The circumstances of the discovery were striking. When emergency responders reached the scene, they found the man lying on the ground directly below his own apartment window. Inside the apartment, investigators documented a state of considerable disorder, with furniture and objects disturbed in a pattern that suggested violent or chaotic activity before the fall. Crucially, the man had no documented psychiatric history, and there were no indicators of suicidal intent, such as a note or prior statements. This combination of findings, the authors argue, is most consistent with acute agitation or a dissociative state induced by substance use rather than a deliberate act of self-harm.

An autopsy confirmed that death resulted from multiple traumatic injuries characteristic of a fall from height, establishing the mechanical cause of death beyond doubt. But establishing why the man went through the window required toxicology. Analysis of peripheral blood, drawn from a site away from the torso where postmortem redistribution can distort concentrations, revealed 3-MeO-PCE at 80 micrograms per liter, along with 13 micrograms per liter of its metabolite 3-HO-PCE. The analysis also detected tramadol at 674 micrograms per liter and ethanol at 0.18 grams per liter, indicating that the man had consumed an opioid analgesic and a modest amount of alcohol alongside the dissociative compound.

3-MeO-PCE belongs to the arylcyclohexylamine family, a chemical lineage that traces back to phencyclidine, better known as PCP, which was synthesized in the 1960s and briefly developed as a surgical anesthetic before its severe psychotomimetic effects ended clinical use. Arylcyclohexylamines act as potent antagonists of the N-methyl-D-aspartate receptor, a glutamate-gated ion channel central to synaptic plasticity, perception, and consciousness. Blocking this receptor produces the profound dissociation characteristic of drugs like ketamine: users report detachment from their bodies, distorted perception of space and gravity, analgesia, and in deep intoxication a trance-like state often described as the K-hole. Laboratory work has shown that 3-MeO-PCE and related methoxy analogues bind the NMDA receptor with high affinity and selectivity, and rodent studies have demonstrated phencyclidine-like abuse liability and psychosis-like neurocognitive effects.

What makes the compound particularly concerning from a public health standpoint is how little is known about it. 3-MeO-PCE is an analogue of eticyclidine, itself a potent PCP derivative, and it emerged on the recreational market as part of the broader wave of new psychoactive substances that continue to proliferate worldwide. According to the authors, information on its pharmacology, metabolism, and toxicity remains scarce, and before this report only a single postmortem blood concentration had ever been published in the scientific literature. Earlier studies have mapped its metabolism in human liver microsomes, zebrafish models, and human urine samples using high-resolution mass spectrometry, identifying 3-HO-PCE as a key metabolite, but real-world fatality data have been almost entirely absent.

The detection of the metabolite alongside the parent compound carries forensic significance. Finding 3-HO-PCE in the blood confirms that the man ingested 3-MeO-PCE and that his body had begun processing it, rather than the substance being introduced after death or through contamination. The relatively low concentration of 80 micrograms per liter suggests the man was not at the extreme end of intoxication by dose, yet dissociative drugs are notorious for producing dramatic behavioral disturbance at doses that do not approach classical toxicity. This disconnect between blood concentration and behavioral effect is a recurring challenge in forensic toxicology, particularly for NMDA receptor antagonists, where impairment of judgment, perception of height, and reality testing can occur well before life-threatening physiological effects appear.

The co-detection of tramadol adds another layer of pharmacological complexity. Tramadol is an atypical opioid analgesic that inhibits the reuptake of serotonin and norepinephrine in addition to its weak mu-opioid receptor activity, and it has a well-documented capacity to lower the seizure threshold and to trigger hallucinations, particularly at higher doses or in combination with other serotonergic or psychotropic substances. A systematic review of tramadol-associated hallucinations has catalogued numerous cases in which patients experienced vivid sensory disturbances without any primary psychiatric illness. Alcohol, meanwhile, is a central nervous system depressant that can potentiate the cognitive disorganization produced by dissociatives and further erode impulse control. The authors suggest that the combined effect of these three substances may have potentiated the behavioral disturbance that preceded the fall.

Self-defenestration, the act of falling or jumping from a window, has appeared repeatedly in the literature on dissociative drugs. Case series involving 3-MeO-PCP, a closely related methoxy analogue, have documented severe agitation, psychosis, and dangerous behavior among users presenting to emergency departments in Sweden and France. Ketamine intoxication has likewise been associated with accidents in which users, detached from their bodies and unable to accurately perceive their surroundings, walked into traffic or fell from buildings. The phenomenology of the dissociative state, in which the sense of self becomes separated from the body and the environment takes on an unreal quality, provides a plausible mechanism for how a person with no suicidal ideation could end up outside a window. The disordered apartment in this case fits that picture, suggesting a period of agitated confusion before the fatal fall.

The case also underscores the analytical challenges that new psychoactive substances pose for forensic laboratories. Standard immunoassay drug screens are calibrated to detect established compounds like PCP and ketamine and frequently fail to flag their novel analogues, sometimes producing false negatives or, conversely, false positives that require confirmation by more sophisticated methods. Detecting 3-MeO-PCE required targeted liquid chromatography coupled with high-resolution mass spectrometry, an approach that can identify and quantify obscure compounds in blood and other biological matrices. The authors validated their quantitative method according to established toxicology guidelines, and the resulting concentration data now constitute only the second published postmortem peripheral blood value for this drug, a small but meaningful addition to a forensic literature that lags far behind the pace at which new substances reach the market.

For toxicologists, emergency physicians, and harm reduction services, the report is a warning about a compound most clinicians have never heard of. Monitoring systems run by the United Nations Office on Drugs and Crime and the European Union Drugs Agency have tracked the steady appearance of arylcyclohexylamine derivatives among new psychoactive substances, and user communities circulate detailed dosing and experience reports online even as formal pharmacological data remain thin. The French authors emphasize that while trauma was the immediate cause of death, the potential of 3-MeO-PCE to induce serious behavioral disturbances deserves recognition, particularly when combined with other psychoactive substances. As dissociative analogues continue to spread through recreational markets faster than science can characterize them, each carefully documented case becomes a critical data point for recognizing, treating, and ultimately preventing the next unexplained fall from a window.

Subject of Research: Forensic toxicology of 3-MeO-PCE, a dissociative arylcyclohexylamine new psychoactive substance, in a fatal self-defenestration case

Article Title: Self-defenestration associated with 3-MeO-PCE ingestion

Article References: Knapp-Gisclon, A., Mayer, C., Bellouard, M., Oliero, J., Rambaud, C., & Alvarez, J.-C. (2026). Self-defenestration associated with 3-MeO-PCE ingestion. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-03993-w

Image Credits: AI Generated

DOI: 10.1007/s00414-026-03993-w

Keywords: 3-MeO-PCE, new psychoactive substances, arylcyclohexylamines, NMDA receptor antagonists, forensic toxicology, self-defenestration, dissociative drugs, postmortem blood concentration, tramadol, ketamine analogs, 3-HO-PCE, International Journal of Legal Medicine

The study, published in Archives of Sexual Behavior, was conducted by a team including Lucia Gallego-Deike, Marcos Bella-Fernández, and Hilario Blasco-Fontecilla, working with data from the Spanish Observatory on Drugs and Addictions. The EWSD is a multinational, web-based survey coordinated every three years by the European Union Drugs Agency across 30 European and neighboring countries. Spain has participated since 2021, and the 2024 edition collected data between May and June. To qualify, participants had to be 18 or older and report having used at least one of several substances in the previous year, including cannabis, cocaine, ecstasy/MDMA, amphetamine, methamphetamine, heroin, or any new psychoactive substance. The questionnaire spanned 225 questions and took roughly fifteen minutes to complete.

The technical detail in the new paper is considerable. Respondents were classified by both sex assigned at birth and gender identity, allowing the researchers to distinguish cisgender men, cisgender women, and transgender or non-binary participants. A respondent was counted as using a drug if they had consumed it within the previous 12 months, and they were categorized as engaging in chemsex if they identified a chemsex party as a context of use for at least one substance in that period. Statistical comparisons between subgroups used t-tests for quantitative variables and chi-square tests for qualitative ones, with all analyses performed in R version 4.3.2.

The most striking findings concern why people use drugs at all. Cannabis and heroin stand apart from the general recreational pattern. Nearly half of cannabis users, 49.73 percent, said they used it to relax or manage stress, as did 30.14 percent of heroin users. About a quarter of users of each substance reported taking them to improve sleep, and 26.35 percent reported using them to cope with anxiety or depression. This self-medication profile contrasts sharply with substances such as ecstasy/MDMA, where 73 percent of users reported purely recreational motives. The researchers note that comparable proportions of cannabis and heroin users reported consumption driven by dependence, despite the two substances carrying very different social perceptions of risk.

Context matters as much as motive. Across the board, drugs were most often consumed at home, but music festivals and parties emerged as the most frequent public settings. This aligns with a well-established body of evidence: wastewater analyses in several countries have documented spikes in psychostimulant concentrations during festivals featuring rap, house, dance, pop, or rock music, and surveys of festival attendees have repeatedly identified MDMA and cannabis as the most common illicit drugs in those environments. Clubs and bars ranked slightly lower. Only cannabis and heroin appeared across an unusually wide range of environments, including schools, supervised drug use rooms, and natural settings.

The sexualized drug use findings carry the most public health weight. Sexualized drug use, or SDU, is an umbrella term for the intentional use of substances to enhance or facilitate sexual activity, practiced across genders and orientations but disproportionately represented among sexual-orientation and gender minorities. The paper emphasizes that no unified definition of SDU exists, and chemsex, its most specific subset, is likewise not recognized as a distinct diagnostic entity in the ICD-11. Chemsex conventionally involves stimulants, methamphetamine, GHB/GBL, and mephedrone, used before or during prolonged group sexual sessions, historically among men who have sex with men, often facilitated by geosocial networking apps and hosted in private residences or sex-on-premise venues.

The new data show that among the 874 respondents reporting drug use for sexual enhancement, 81.46 percent used only one substance, while 12.93 percent used two or more, and use of five or more drugs was rare. Male respondents reported sexual enhancement use at roughly twice the rate of female respondents. Cisgender men reported higher rates of sexualized use of cocaine (crack), heroin, and MDMA than cisgender women, while transgender or non-binary participants reported higher MDMA use for sexual purposes than cisgender women. Cannabis was the most frequently used substance for sexual enhancement across all gender groups, a finding consistent with its overall status as the most widely used illicit drug.

Chemsex itself remained a minority practice but displayed a distinctive signature. Of the 206 respondents who attended at least one chemsex session in the past year, the vast majority, 170 or 81.33 percent, were cisgender men, followed by 22 cisgender women (10.53 percent) and 14 transgender or non-binary individuals (6.70 percent). Methamphetamine and new psychoactive substances were primarily linked to chemsex parties, and the route of administration differed markedly from general drug users: injection and rectal insertion were far more prevalent among chemsex attendees, as was smoking in pipes. Injection within chemsex contexts, sometimes called slamsex, is a particularly high-risk variant associated with elevated likelihood of addiction, psychosis, neurological harm, overdose, and sexually transmitted infections.

The sociodemographic profile of sex-related drug users also diverged from the rest of the sample in statistically significant ways. Sex assigned at birth and gender identity both differed between groups, with p-values of 0.004 and below 0.001 respectively, and sex-related drug users were slightly younger, more often students, and included a modestly higher proportion of transgender or non-binary individuals, 3.66 percent versus 2.38 percent. Employment status also differed significantly. Notably, living situation, income, residency, and education showed no significant differences, echoing review literature that has found inconsistent sociodemographic correlates of SDU beyond gender and age.

Perhaps the most consequential implication of the study is its suggestion that chemsex epidemiology is shifting. Though the practice is traditionally associated with men who have sex with men, the presence of women among chemsex participants in this sample suggests the phenomenon may be expanding into heterosexual populations, a trend supported by emerging but still limited research on heterosexual men and women in party and club subcultures. Chemsex carries substantial risks, including unsafe sexual practices that raise HIV and hepatitis C transmission, drug-induced disinhibition that can lead to non-consensual encounters, and long-term mental health problems such as depression, anxiety, sleep disorders, psychotic symptoms, and cognitive decline. The authors argue that prevention campaigns, which have until now focused primarily on MSM communities, must adapt. They call for targeted strategies including health education, harm reduction, inclusive care services, and professional training, measures they say are essential to reduce harm and improve health outcomes as the landscape of sexualized drug use evolves.

Subject of Research: Sexualized drug use and chemsex patterns among illicit drug users in Spain

Article Title: Patterns of Drug Use Across Social and Sexual Contexts in Spain: Insights From the European Web Survey on Drugs 2024

Article References: Gallego-Deike, L., Bella-Fernández, M., López-Sánchez, L. M., Brime-Beteta, B., Ruiz-Medina, S., & Blasco-Fontecilla, H. (2026). Patterns of Drug Use Across Social and Sexual Contexts in Spain: Insights From the European Web Survey on Drugs 2024. Archives of Sexual Behavior. https://doi.org/10.1007/s10508-026-03525-y

Image Credits: AI Generated

DOI: 10.1007/s10508-026-03525-y

Keywords: chemsex, sexualized drug use, European Web Survey on Drugs, methamphetamine, cannabis, MDMA, public health, men who have sex with men, harm reduction, Spain, new psychoactive substances, drug use patterns

The research team, led by Lateef Olutoyin Oluwole and Adetunji Obadeji of the Department of Psychiatry, conducted four focus group discussions with 22 young adults aged 18 to 47 who were receiving treatment for mental and behavioural disorders linked to psychoactive substance use. Seventeen of the participants were male and five female, with a mean age of just over 25 years. Most had tertiary education, a detail that punctures the stereotype of the fraudster as an uneducated dropout. Participants were identified through careful, ethically supervised clinical screening, and only those who had personally disclosed direct or vicarious involvement in internet fraud were included. Sessions lasted between 60 and 90 minutes and were analysed thematically using Braun and Clarke’s established six-step framework, with the research team continuing until data saturation was reached at the fourth discussion.

The scale of the underlying problem is staggering. Recent studies cited by the authors document lifetime psychoactive substance use among Nigerian university students reaching 86 percent, with regional prevalence rates of 44 percent for alcohol, 30 percent for tramadol, between 6 and 16 percent for cannabis, and 11 percent for codeine. More alarming still is the emergence of new psychoactive substances, including synthetic cannabinoids sold under street names such as “Wiz,” “Black Mamba” and “Colorado,” which are marketed through online platforms and local outlets with deceptive labelling and are associated with severe neuropsychiatric effects including psychosis and hallucinations. Against this backdrop, Nigeria’s demographic profile, in which individuals under 35 constitute more than 70 percent of the population, means that the intersection of drug use and cybercrime touches an enormous share of the nation’s future workforce.

What the focus groups revealed is that the relationship between substances and fraud operates through at least three distinct patterns. The first is functional linkage: substances used deliberately to enhance fraudulent performance. Participants described smoking synthetic cannabinoids to stay awake through long nights of online scamming, or using tramadol and cannabis to summon the confidence needed to manipulate victims. “When they use tramadol or loud, it gives them confidence to talk to clients online,” one participant explained. The second pattern is independence, where the two behaviours coexist without direct connection; many participants knew fraudsters who avoided drugs entirely, and drug users with no involvement in fraud. The third, and perhaps most destructive, is bidirectional reinforcement, in which fraud proceeds fund escalating substance use while substances sustain the emotional and physical capacity to continue defrauding victims.

Peer influence emerged as the most consistently cited driver across every discussion group. The researchers frame this through Sutherland’s Differential Association Theory, which holds that deviant behaviour is learned through intimate social interaction. Participants described acquiring not only the technical knowledge of fraud schemes but also the rationalisations that make them acceptable. “If your guy is doing Yahoo and you see him driving Benz, you go want join too,” one speaker said. Crucially, the authors found that peer influence now extends beyond face-to-face networks into mediated channels: Instagram displays of fraud-derived wealth create aspirational models that reach far beyond immediate friendship circles, effectively digitising the social transmission of deviance.

Beneath the peer dynamics lies a structural engine that the researchers interpret through Merton’s Strain Theory. When culturally prescribed goals, financial success, material display, social status, are pursued in a society where legitimate routes such as education and formal employment are systematically blocked, illegitimate pathways become rational choices for some. Participants spoke of poverty as the fundamental push factor and of intense family expectations, particularly on firstborn sons, to provide. “It’s poverty that is pushing them… they want to make it fast,” one participant said. The frustration of educated unemployment, the perception that the system has failed, and the visible rewards of fraud combined to produce what the authors describe as a maladaptive response to the disjuncture between aspiration and opportunity.

Perhaps the most unsettling finding concerns the family and community. Rather than uniformly condemning fraud, participants described a spectrum of parental responses ranging from unknowing enablement to active complicity. Some parents remained silent once money began flowing home; a few reportedly prayed for their sons’ success in fraud; others took their children to traditional healers, or babalawos, for spiritual “fortification” before fraudulent ventures. The authors argue that this cultural ambivalence, a system that simultaneously prohibits and enables, may be more consequential for youth behaviour than either clear condemnation or clear approval, because it creates exploitable ambiguity. Social media, pop culture and the visible material success of “big boys” reinforce the normalisation, with participants noting that fraud is now regarded in many communities as a normal job, morally softened by comparisons such as “not stealing with a gun.”

The biopsychosocial model completes the theoretical triad. Biologically, substances alter brain chemistry in ways that impair judgment and increase impulsivity, effects that may facilitate fraud. Psychologically, substances serve as self-medication for the distress arising from economic pressure, family conflict and the moral tensions of deceiving others. Socially, peer networks supply both the context for use and the normative framework for fraud. The authors stress that these frameworks are complementary rather than competing: strain theory explains the structural pressures, differential association explains how deviant responses are transmitted, and the biopsychosocial model explains how these forces manifest in individual experience.

Yet beneath the bravado and the Benz photographs, the study documents a hidden toll. Despite widespread normalisation, participants consistently reported guilt, remorse, depression, anxiety, sleep disturbance, intrusive thoughts about victims and difficulty forming trusting relationships. “Sometimes it’s hard to sleep, even after making money. The guilt is real,” one speaker admitted. Others described violence and depression when fraud ventures failed. This coexistence of external reward and internal distress, the authors note, complicates simplistic portrayals of “Yahoo boys” as simply immoral; even within deviant subcultures, individuals retain a moral awareness that carries real psychological cost, and young adults with mental health conditions appear significantly more vulnerable to new psychoactive substances, which in turn further impair judgment and increase susceptibility to fraudulent involvement.

The participants themselves offered a roadmap for intervention that the authors endorse: economic empowerment and job creation, parenting and family training programmes that replace punitive discipline with emotional connection, recreational and vocational initiatives, mental health support and mentorship, and faith-based moral reorientation. “If there are jobs or skills training, many won’t do Yahoo or drugs,” one participant said. The researchers caution that their sample, drawn from a single treatment facility in southwestern Nigeria, may limit generalisability, and that the clinical setting could have emphasised pathological aspects of participants’ experiences. Still, the consistency of narratives across groups lends weight to the central conclusion: substance use and internet fraud among Nigerian youths are not isolated acts of deviance but interconnected maladaptive coping strategies within contexts of structural inequality, demanding integrated, youth-focused responses that address mental health, family dynamics and economic opportunity together rather than treating either crisis alone.

Subject of Research: The psychosocial and cultural drivers linking psychoactive substance use and internet fraud among Nigerian youths

Article Title: Psychosocial and cultural dynamics shaping substance use and internet fraud among Nigerian youths

Article References: Oluwole, L. O., Obadeji, A., Ajiboye, A. S., & Atofarati, M. A. (2026). Psychosocial and cultural dynamics shaping substance use and internet fraud among Nigerian youths. Discover Mental Health, 6(1), Article 178. https://doi.org/10.1007/s44192-026-00476-7

Image Credits: AI Generated

DOI: 10.1007/s44192-026-00476-7

Keywords: substance use, internet fraud, Yahoo Yahoo, Nigeria, youth, cybercrime, mental health, peer influence, strain theory, new psychoactive substances, qualitative research, cultural normalisation

The scale of the problem the researchers confront is enormous. According to the United Nations Office on Drugs and Crime, new psychoactive substances are compounds that threaten public health yet fall outside the 1961 Single Convention on Narcotic Drugs and the 1971 Convention on Psychotropic Substances. By the end of 2024, the European Union Drugs Agency was monitoring 1,000 such substances in Europe, 47 of them first reported that year. Between 2012 and 2025, the UNODC Early Warning Advisory logged 1,391 new psychoactive substances across 152 countries and territories, while the NPS Discovery program of the Center for Forensic Science Research and Education identified 174 compounds for the first time in the United States between 2018 and 2024, including 20 in 2024 alone. Each new structure demands a rapid toxicological evaluation, and the zebrafish, with its transparent embryos, rapid development, and vertebrate reward circuitry, has become one of the most practical platforms for that task.

The two compounds chosen for this study illustrate the cat-and-mouse dynamics of the synthetic drug market. ADB-INACA is a so-called tail-less precursor, an indazole carboxamide lacking the N-alkyl tail found in potent controlled SCRAs such as ADB-BUTINACA. First flagged by NPS Discovery in 2023, it has since appeared in nine drug-material cases and seven toxicological specimens. CHO-4′Me-5′Br-FUBOXPYRA, by contrast, was engineered with a novel 5-bromo-4-methylpyridin-2(1H)-one core specifically to evade China’s 2021 generic ban on synthetic cannabinoids. First identified in Europe in 2022, it has since surfaced in Germany, Italy, Slovenia, Sweden, Lithuania, Romania, Spain, and, as of 2023, in United States drug material, with a first toxicological detection reported in 2024. Prior receptor studies suggested both compounds carry only limited CB1 activity, making them ideal candidates to test whether structural loopholes translate into genuine physiological risk.

To answer that question, the team, led by Leonardo Costalonga Rodrigues and colleagues at the Universidade Estadual de Campinas in Brazil and the University of Utah, deployed a battery of complementary assays. Acute embryonic toxicity was measured with the fish embryo acute toxicity test standardized by the Organization for Economic Co-operation and Development as guideline 236, in which newly fertilized eggs are exposed to a compound for 96 hours and scored for lethal endpoints: coagulation of the egg, lack of somite formation, failure of the tail bud to detach from the yolk sac, and absence of heartbeat. Concentrations ranged from 0.001 to 10 micromolar, with 16 embryos per concentration, and sublethal observations such as pericardial edema, loss of posture, and heart rate changes were recorded daily under a stereoscopic microscope. At three days post-fertilization, heartbeats of five larvae per group were filmed for 20 seconds and extrapolated to beats per minute, and at four days each larva was touched on the tail with a micropipette tip to test its escape response.

The results from embryonic exposure were strikingly mild. Both SCRAs produced low mortality across the entire tested range, with embryo coagulation the only lethal endpoint observed, and even that appeared in fewer than 19 percent of embryos at any time point. CHO-4′Me-5′Br-FUBOXPYRA, however, did produce sublethal cardiac and postural effects that crossed the study’s 30 percent reporting threshold: pericardial edema at 10 micromolar, loss of posture in 69 percent of larvae at the highest concentration at three days post-fertilization, and a statistically significant reduction in heart rate at 10 micromolar, with a p-value below 0.01. Escape responses were blunted at all concentrations above 0.1 micromolar for this compound. ADB-INACA produced mainly impaired escape responses at select concentrations without significant lethality or cardiac effects. A companion maximum tolerated concentration test in larvae, exposing animals from five to eight days post-fertilization, largely confirmed this picture, with absent escape responses and occasional loss of posture at the highest doses but little else.

The behavioral experiments are where the study breaks genuinely new ground. Social behavior was assessed at 21 days post-fertilization using the Fishbook assay, a scalable, fully automated system first described in 2022. Juvenile zebrafish swim in a three-dimensional-printed rectangular arena divided by transparent windows into a central test compartment, an end compartment holding a live fish as a social stimulus, and an empty end compartment. Forty-four arenas are imaged simultaneously through a telecentric lens system, and software streams frame-by-frame positional coordinates that are converted into a social score between negative one and one, where higher values indicate that a fish spent more time near the social stimulus. Neither compound altered the social score: fish exposed to 10 micromolar ADB-INACA averaged 0.484 versus 0.424 in controls, and fish exposed to 10 micromolar CHO-4′Me-5′Br-FUBOXPYRA averaged 0.658 versus 0.623 in controls. To the researchers’ knowledge, this is the first in vivo evaluation of any SCRA’s impact on social interaction.

The final and arguably most ambitious assay tested whether the new compounds could drive drug-seeking behavior. Building on a paradigm developed by Bossé and Peterson, the team constructed a custom arena with two submersible platforms, an “active” one wired to a Raspberry Pi minicomputer and infrared cameras that trigger a peristaltic pump releasing a drug solution, and an “inactive” one that dispenses nothing. A recirculation system prevented drug diffusion to the inactive corner. Adult zebrafish first learned over five days of food conditioning that crossing the active platform yields a reward, then received five days of drug treatment. Hydrocodone served as the positive control, and it performed as expected: fish consistently sought the opioid, triggering the active platform far more often than the inactive one. Fish exposed to 0.625 micrograms of CHO-4′Me-5′Br-FUBOXPYRA per trigger, however, showed a progressive decline in active-platform crossings indistinguishable from the water-treated controls, indicating the compound lacked reinforcing effects under these conditions. ADB-INACA was not carried into self-administration testing because the earlier toxicity assays had revealed no significant effects.

The authors connect their findings to the wider pharmacological literature on these structural families. Earlier work on tail-less indazole precursors found minimal CB1 receptor activity for ADB-INACA, with concentration-response curves that failed to reach a clear plateau and potency estimates that could not be determined, while brominated analogs showed only partial receptor activation even at 100 micromolar. For CHO-4′Me-5′Br-FUBOXPYRA, a 2025 investigation of its metabolism identified four hydroxylated metabolites and a limited activation potential at both CB1 and CB2. The new zebrafish data align neatly with that weak receptor profile: limited cannabinoid-like behavioral effects, normal social behavior, no drug-seeking, and only modest cardiotoxicity for the brominated pyridone compound in the form of pericardial edema and reduced heart rate at the highest concentration tested. The study does have limitations the authors themselves acknowledge: only two compounds were evaluated, exposures were acute rather than chronic, and no molecular or neurochemical endpoints were measured to confirm what the receptors were doing during the behavioral tests.

Even so, the methodological takeaway may prove more consequential than the individual toxicological verdicts. By combining OECD-standard embryo testing, larval maximum tolerated concentration assays, the automated Fishbook social paradigm, and an operant self-administration assay within a single vertebrate model, the study demonstrates an end-to-end pipeline capable of profiling a novel psychoactive substance from developmental toxicity to abuse liability in a matter of weeks. The authors describe these assays as feasible, reproducible, and translationally relevant, and argue that they can be extended to a much larger number of emerging compounds, offering a rapid toxicological surveillance bridge between preclinical toxicology and public health needs. As forensic chemists continue to identify new SCRAs faster than regulators can schedule them, the humble zebrafish may become one of the fastest ways to learn whether the next designer cannabinoid is a genuine threat or, as appears to be the case for ADB-INACA and CHO-4′Me-5′Br-FUBOXPYRA at the concentrations tested, a structural dodge with surprisingly little punch.

Subject of Research: Toxicity and behavioral effects of the synthetic cannabinoid receptor agonists ADB-INACA and CHO-4′Me-5′Br-FUBOXPYRA in zebrafish models

Article Title: Evaluation of synthetic cannabinoid receptor agonists toxicity in zebrafish (Danio rerio) through self-administration and Fishbook assays

Article References: Rodrigues, L. C., Muhsen, M., Aliabadi, S. R., Zhang, T., Maurer-Morelli, C. V., Peterson, R. T., & Costa, J. L. (2026). Evaluation of synthetic cannabinoid receptor agonists toxicity in zebrafish (Danio rerio) through self-administration and Fishbook assays. Discover Toxicology, 3(1), Article 4. https://doi.org/10.1007/s44339-026-00049-x

Image Credits: AI Generated

DOI: 10.1007/s44339-026-00049-x

Keywords: synthetic cannabinoids, new psychoactive substances, zebrafish, toxicology, ADB-INACA, CHO-4′Me-5′Br-FUBOXPYRA, Fishbook assay, self-administration, drug-seeking behavior, CB1 receptor, embryotoxicity, social behavior

The review, conducted by researchers at the Universidade Federal do Rio Grande do Sul in Brazil, searched PubMed/Medline, Scielo and Google Scholar for articles and technical notes published between 2020 and 2024. From an initial pool of 108 works, 41 studies were included in the final analysis. The authors note that the United Nations Office on Drugs and Crime had recorded more than 120 opioid receptor agonists by 2024, divided into five subgroups: fentanyl analogues, U-series substances, nitazenes, piperazines and a miscellaneous category. Nitazenes stand out within this crowded field because of the sheer affinity of some analogues for the µ-opioid receptor. The first fatal case involving isotonitazene, one of the most notorious members of the family, was reported in the United States in August 2019, only months after the compound first appeared on the recreational market. Since then, metonitazene, butonitazene, flunitazene, etodesnitazene, protonitazene and N-pyrrolidinoetonitazene have all been identified in forensic casework, and between 2019 and 2025 a total of 32 nitazene analogues were reported by 36 countries.

What makes the current wave of nitazene activity particularly hazardous is the way these substances reach consumers. They are rarely sold as standalone products. Instead, they are frequently detected as adulterants in heroin, benzodiazepines, synthetic cannabinoids and even cocaine, often without the knowledge of the people who buy them. This adulteration broadens the population at risk far beyond habitual opioid users. In Brazil, a country where opioid misuse had historically been considered statistically insignificant, the arrival of nitazenes came through an unexpected channel: herbal smoking blends sold as synthetic cannabinoids. An analysis of 140 opioid samples seized by São Paulo state police over roughly one year found that 95 percent contained nitazene analogues, with metonitazene present in 72 percent of the nitazene-positive samples. In most of these cases the compounds appeared in combination with other drugs, meaning users were inhaling a potent opioid hidden inside a product they believed contained something else entirely.

The chemistry behind this potency is instructive. Nitazene analogues share a benzimidazole nucleus linked to an amine group, and small modifications to the side chains produce compounds with markedly different pharmacological profiles. Etonitazene, first synthesized in 1957, proved in animal models to be between 100 and 1000 times more potent than morphine, making it the most powerful compound of the 2-benzylbenzimidazole subclass. Isotonitazene ranked second in potency, followed by protonitazene, metonitazene and butonitazene. The electron-withdrawing nitro group at the 5-position of the ring, the structural feature that gives the nitazenes their name, reduces the basicity of the heteroaromatic ring and appears central to receptor binding. The basic properties of these molecules generally dominate over their acidic ones, owing to two basic moieties: the benzimidazole ring and a tertiary amine in the side chain. These subtle structural differences translate into dramatic differences in how strongly each compound activates opioid receptors and how long it stays bound to them.

Once inside the body, nitazene analogues follow a metabolic route that creates its own set of problems. Biotransformation is mediated primarily by cytochrome P450 enzymes in the liver, particularly the CYP2D6, CYP2B6 and CYP2C8 isoforms. Phase I metabolism oxidizes the parent compounds, introducing reactive and polar functional groups, while phase II conjugation adds glucuronides and sulfates to facilitate urinary excretion. Crucially, some of the metabolites generated along the way are pharmacologically active in their own right. The main urinary metabolite of isotonitazene, N-desethyl-isotonitazene, is actually more potent than the parent drug and has itself appeared for sale on the drug market. Metabolite profiling shows that the O-desalkyl metabolites of isotonitazene and metonitazene are the same molecule, complicating the interpretation of toxicological results, and in silico analysis of etazene suggests it is three times more lipophilic than morphine, crosses the blood-brain barrier readily and inhibits several major CYP enzymes. Genetic variation in CYP450 activity means metabolism can differ substantially between individuals, adding further unpredictability to overdose risk.

Clinically, nitazene exposure produces the effects expected of powerful opioids: euphoria, pain relief and relaxation, followed by drowsiness, dizziness, nausea, constipation and dry mouth. The life-threatening effect is respiratory depression, which can progress to cardiac arrest. Prolonged exposure leads to tolerance, dependence and a characteristic withdrawal syndrome that begins with anxiety, drug craving and lacrimation before escalating to tremors, muscle pain, tachycardia, hypertension and gastrointestinal distress. What distinguishes nitazenes from earlier opioid threats is the difficulty of reversing their overdoses with naloxone, the standard opioid antidote. Laboratory work suggests that nitazenes and fentanyl analogues dissociate slowly from the µ-opioid receptor, reducing naloxone sensitivity. A systematic review found that nitazene overdoses typically required naloxone doses in the range of 1 to 6 milligrams, compared with the 0.4 to 0.8 milligrams usually sufficient for heroin. In one Brazilian clinical case involving N-pyrrolidinoprotonitazene, a patient with a blood concentration of 3.0 nanograms per milliliter required three ampoules of naloxone, equivalent to 1.2 milligrams, before respiratory function improved. The short half-life of naloxone relative to these synthetic opioids also means respiratory depression can relapse, demanding repeated dosing and sustained monitoring.

Detecting nitazenes in biological samples presents a formidable analytical challenge. Because these compounds are so potent, they are consumed at microgram doses and clear the body rapidly, so timely sampling and highly sensitive instruments are essential. Liquid chromatography coupled with tandem mass spectrometry has become the method of choice, typically using whole blood as the primary matrix and liquid-liquid extraction for sample preparation. Related techniques, including GC-MS and LC-QTOF-MS, allow detailed chemical differentiation between analogues. Forensic scientists emphasize that robust documentation of exposure requires detecting the parent compound alongside N-desethyl, O-desalkyl and N-desethyl-O-desalkyl biomarkers, since metabolites are often more abundant than the original drug. Adding to the confusion, illicit production by the original synthetic route can generate positional isomer impurities that confound analytical interpretation. The review also highlights a promising harm-reduction tool: nitazene test strips, a lateral flow immunoassay commercially available since early 2024 and calibrated against isotonitazene. However, a Belgian laboratory evaluation found the strips failed to detect two analogues, metodesnitazene and etodesnitazene, even at high concentrations, underscoring how quickly the market evolves beyond the tools designed to monitor it.

The regulatory response has been uneven. Brazil formally controlled metonitazene in 2023 and has since listed ten more analogues, while its national rapid alert system for new psychoactive substances was only permanently formalized in early 2025. In a potentially significant shift, China introduced generic control of the entire nitazene structure in June 2025, meaning any new analogue containing the core scaffold is now illegal. The downstream effects on the illicit market remain uncertain, but similar generic controls on fentanyl precursors have previously reshaped supply chains in unpredictable ways. The review’s authors stress that underreporting remains a major obstacle to understanding the true scale of the problem, since many poisonings go unidentified without specialized testing and standardized reporting protocols are still lacking.

The core message from the toxicologists is that health systems must adapt before the crisis deepens. The combination of extreme potency, active metabolites, polysubstance adulteration and naloxone resistance creates a clinical scenario for which many emergency services are not adequately prepared. The authors call for specific intervention protocols, training for health professionals on the risks of synthetic opioids, and urgent advances in toxicokinetic and toxicodynamic research to support detection, treatment and rehabilitation programs. Without that foundation, they warn, public health authorities will continue to underestimate both the prevalence and the lethality of these compounds. As nitazene analogues spread through adulterated drug supplies worldwide, the gap between what users think they are consuming and what is actually in the sample may prove to be the deadliest variable of all.

Subject of Research: Toxicology of emerging nitazene analogue synthetic opioids and their overdose risks

Article Title: Toxicological aspects of emerging nitazene analogues as a new threat to the synthetic drug landscape

Article References: Martins, J. N., dos Santos, B. P., & Arbo, M. D. (2026). Toxicological aspects of emerging nitazene analogues as a new threat to the synthetic drug landscape. Discover Toxicology, 3(1), Article 5. https://doi.org/10.1007/s44339-026-00050-4

Image Credits: AI Generated

DOI: 10.1007/s44339-026-00050-4

Keywords: nitazenes, synthetic opioids, isotonitazene, metonitazene, fentanyl, naloxone, overdose, new psychoactive substances, toxicokinetics, respiratory depression, forensic toxicology, drug detection

The scale of the problem motivating the study is considerable. New psychoactive substances—a shifting family of synthetic compounds designed to mimic the effects of controlled drugs while evading legal restrictions—have become one of the most difficult fronts in global drug policy. Because their chemical structures change constantly, their health consequences are poorly characterized, and people who begin using them in adolescence face heightened risks of lasting neurobiological and psychological harm. The adolescent brain, with its early-maturing reward circuitry and still-developing self-control systems, is particularly vulnerable to substance initiation and to the entrenched patterns of craving that follow.

To uncover the hidden structure of craving, the researchers assessed 1,008 patients in Tianjin whose substance use disorder began during adolescence. Rather than reducing craving to a single score, the team measured three separate dimensions: the intensity of craving itself, the degree to which it interfered with daily functioning, and the effort patients expended resisting it. Latent profile analysis—a form of statistical modeling that sorts individuals into unobserved subgroups based on patterns across multiple measures—was then applied to see whether distinct combinations of these dimensions existed within the sample.

Three profiles emerged, and they were strikingly uneven in size. The largest group, accounting for 54 percent of participants, was labeled relatively stable, showing moderate craving without overwhelming functional disruption. A second group, 40.2 percent of the sample, fell into a high craving struggle category marked by intense urges and an exhausting internal battle to resist them. The smallest but most concerning group, 6 percent, was described as functionally impaired, in which craving severely disrupted everyday life. That two in five patients occupied the high struggle profile underscores how common severe craving is in this population—and how misleading it would be to treat them all identically.

Identifying the profiles was only the first step. The team then asked whether psychosocial information could predict which profile a patient belonged to, using three machine learning models of increasing sophistication: logistic regression, a classical statistical baseline; random forest, an ensemble method that averages many decision trees; and XGBoost, a gradient-boosted algorithm known for its performance on tabular medical data. Performance was evaluated using macro-AUC, accuracy, and Macro-F1 scores, metrics that account for the imbalanced group sizes. XGBoost achieved the strongest discrimination among the three, although the researchers are candid that overall classification performance remained modest—a limitation they attribute to the exploratory nature of the work and the complexity of the underlying constructs.

Perhaps the most clinically valuable output came from interpreting the models. Using SHAP, an explainability technique that quantifies each feature’s contribution to predictions, the researchers identified the psychosocial variables that most strongly distinguished the craving subgroups. Social support emerged as a leading factor, consistent with a growing body of evidence that supportive networks buffer against relapse. Resistance to peer influence also ranked highly—a finding that resonates with developmental research showing adolescence as the period of peak susceptibility to peer pressure. Coping style, childhood adversity, age, and age at first drug use completed the list of key contributors, weaving together life history, developmental timing, and present-day resources into a single predictive picture.

These findings align closely with the biopsychosocial model of addiction, which holds that substance use disorders arise from interactions among biological vulnerability, psychological processes, and social context rather than from any single cause. The prominence of childhood adversity in the models echoes systematic reviews linking early maltreatment to elevated risk of substance misuse, while the role of social support reflects studies demonstrating that perceived support moderates the relationship between stress and relapse. By embedding these factors in a quantitative, subgroup-aware framework, the study gives that conceptual model a practical, data-driven form.

The authors are careful to frame the work as exploratory rather than definitive. The cross-sectional design captures a single moment in time and cannot establish causal direction—for instance, whether low social support drives intense craving or vice versa. The modest discriminative performance means the models are not yet ready for individual-level clinical decisions, and the data, which contain sensitive personal information, are not publicly available for reasons of privacy protection. Still, the researchers argue that the approach may provide preliminary evidence for risk stratification and for subgroup-sensitive addiction nursing support, in which care is tailored to whether a patient fits the stable, high struggle, or functionally impaired pattern.

If future longitudinal studies confirm and refine these profiles, the implications could be far-reaching. A patient in the functionally impaired group might warrant immediate intensive intervention, while someone in the high craving struggle group might benefit most from coping-skills training and peer-resistance support, and those in the stable group from relapse prevention and social strengthening. In an era when new psychoactive substances continually outpace regulation and traditional treatment models, the ability to sort patients by their actual craving signature—rather than a one-size-fits-all label—could mark a meaningful shift toward precision medicine in addiction care. The study, funded by the Ministry of Education in China, is an early but provocative demonstration that the algorithms of machine learning can find order in one of addiction’s most stubborn and subjective experiences.

Subject of Research: Exploratory risk stratification of adolescent-onset new psychoactive substance use disorder using latent craving profiles and machine learning

Article Title: Exploratory Risk Stratification of Patients With Adolescent-Onset New Psychoactive Substance Use Disorder: Integrating Latent Craving Profiles, Psychosocial Factors, and Machine Learning

Article References: Zhuang, S., Che, X., Song, Y., Li, S., Shang, X., Shi, L., Zhang, X., Song, C., Jing, J., Fan, J., Qin, S., Xu, Z., Zhang, J., Li, J., Li, L., Hou, K., & Jiang, Y. (2026). Exploratory Risk Stratification of Patients With Adolescent-Onset New Psychoactive Substance Use Disorder: Integrating Latent Craving Profiles, Psychosocial Factors, and Machine Learning. International Journal of Mental Health and Addiction. https://doi.org/10.1007/s11469-026-01714-3

Image Credits: AI Generated

DOI: 10.1007/s11469-026-01714-3

Keywords: new psychoactive substances, adolescent-onset substance use disorder, craving, latent profile analysis, machine learning, XGBoost, SHAP, social support, childhood adversity, risk stratification, addiction nursing, peer influence