Shingles Nerve Pain Linked to Sharply Higher Mental Health Risks in 15,454-Patient Study

A large retrospective cohort study drawing on the health records of tens of thousands of American adults has found that postherpetic neuralgia, the lingering nerve pain that can follow an outbreak of shingles, is associated with a significantly elevated risk of developing mental disorders in the months that follow. The research, published in BMC Psychiatry, analyzed data from the TriNetX U.S. Collaborative Network and compared 15,454 patients who developed postherpetic neuralgia after herpes zoster with an equal number of shingles patients who did not. Over a six-month follow-up window, those with the chronic pain condition were 26 percent more likely to receive a new psychiatric diagnosis, a difference the researchers describe as clinically meaningful given the size and diversity of the population studied.

Postherpetic neuralgia arises when the varicella-zoster virus, the same pathogen responsible for chickenpox, reactivates years or decades later as shingles and damages sensory nerve fibers. In some patients the pain persists long after the characteristic blistering rash has healed, producing burning, stabbing, or electric shock-like sensations that can last for months or even years. While the condition is well recognized as a driver of reduced quality of life, sleep disturbance, and functional impairment, the authors of the new study note that its association with subsequent formal psychiatric diagnoses has remained underexplored, particularly in large and demographically varied populations. Their work was designed to fill that gap using real-world clinical data rather than small, single-center samples.

The methodology behind the study reflects the growing power of federated electronic health record networks. The researchers identified patients aged 18 and older who received a new diagnosis of herpes zoster between 2016 and 2023. Those diagnosed with postherpetic neuralgia within one month of the shingles diagnosis formed the exposed group, while patients who did not develop the complication formed the comparison group. Crucially, the team excluded anyone who had been diagnosed with any mental disorder before the shingles diagnosis or up to one month afterward, a design choice intended to ensure that the psychiatric outcomes being measured were genuinely new conditions rather than pre-existing ones. After propensity score matching, which balanced the two groups on demographic and clinical characteristics, each cohort contained exactly 15,454 patients.

Propensity score matching is a statistical technique widely used in observational research to mimic the conditions of a randomized trial. Because patients are not randomly assigned to develop postherpetic neuralgia, differences between the groups in age, sex, comorbidities, or healthcare utilization could otherwise confound the results. By matching patients on these covariates and checking balance with standardized mean differences, the investigators reduced the likelihood that the observed association between the pain condition and mental illness is an artifact of underlying differences between the populations. The outcome measure was the hazard ratio, a statistic that captures the relative rate at which new events occur in one group compared with another over the follow-up period.

The headline finding was a hazard ratio of 1.26 for any new mental disorder among patients with postherpetic neuralgia, with a 95 percent confidence interval of 1.12 to 1.42. In practical terms, at any point during the six months of follow-up, the PHN group developed psychiatric conditions at a rate roughly a quarter higher than the matched comparison group. When the researchers broke the results down by diagnostic category, two clusters stood out. Mood disorders, which include depression and bipolar spectrum conditions, showed a hazard ratio of 1.33, while anxiety-related conditions showed a hazard ratio of 1.26. Both confidence intervals excluded the null value of one, indicating that these elevations are unlikely to be due to chance alone.

Perhaps the most striking result emerged from the subgroup analyses. When the cohort was stratified by age, the association was strongest among younger adults. Patients aged 18 to 39 who developed postherpetic neuralgia had a hazard ratio of 1.82 for new mental disorders, with a confidence interval of 1.15 to 2.86, meaning their risk was nearly double that of matched peers without the pain condition. This finding challenges the common assumption that the psychiatric burden of shingles complications falls mainly on older adults, who experience the highest rates of the condition itself. Younger patients may face distinct vulnerabilities, including disruption of work, caregiving responsibilities, and social life during prime working years, as well as the psychological shock of developing a condition typically associated with aging.

Sex and race also shaped the pattern of risk. Female patients with postherpetic neuralgia showed a hazard ratio of 1.39 for new mental disorders, compared with 1.21 to 1.60 confidence bounds, suggesting a stronger association in women than in men. Across racial groups, elevated risks were observed for White patients at a hazard ratio of 1.26, Black patients at 1.44, and Asian patients at 1.97, the latter with a wide confidence interval of 1.06 to 3.67 reflecting a smaller number of events. The authors also examined herpes zoster vaccination status and the anatomical site of disease as stratification variables, underscoring their effort to identify which patient groups might benefit most from targeted psychological screening.

The biological plausibility of a link between chronic neuropathic pain and psychiatric illness is well supported by prior literature. Persistent pain activates stress-response systems, including the hypothalamic-pituitary-adrenal axis, and is associated with elevated levels of inflammatory signaling molecules such as interleukin-1, interleukin-6, and tumor necrosis factor alpha, all of which have been implicated in the pathophysiology of depression and anxiety. Chronic pain also disrupts sleep, limits physical activity, and erodes social engagement, each of which is an established risk factor for mood deterioration. In the specific case of postherpetic neuralgia, damage to sensory neurons can produce allodynia, a state in which normally painless stimuli such as clothing against the skin become excruciating, a symptom burden that patients frequently describe as among the most disabling aspects of the condition.

The study’s authors conclude that clinicians should consider early psychological evaluation and intervention for patients with postherpetic neuralgia, rather than treating the condition purely as a pain management problem. Because the elevated risk was measurable within six months of the shingles diagnosis, there is a defined window in which proactive screening for depression and anxiety could plausibly alter trajectories. The findings also add weight to public health arguments for shingles vaccination, since preventing herpes zoster and its most common chronic complication would avert the downstream psychiatric morbidity documented here. The research received support from Chung Shan Medical University Hospital, National Taichung University of Science and Technology, and Taiwan’s Ministry of Science and Technology, and was approved by the institutional review board of Chung Shan Medical University Hospital.

As with all observational studies, some caveats apply. The analysis relies on diagnostic codes recorded in electronic health records, which can vary in accuracy and completeness across institutions, and the six-month follow-up period cannot capture psychiatric outcomes that emerge later. Residual confounding is always possible in matched cohort designs, since factors such as pain intensity, medication use, and socioeconomic circumstances are imperfectly captured in claims-style data. Nevertheless, the scale of the TriNetX network, the rigorous exclusion of pre-existing mental illness, and the consistency of the signal across multiple demographic subgroups lend considerable credibility to the central conclusion: postherpetic neuralgia is not merely a sensory disorder but a condition with measurable consequences for mental health, and the youngest patients, who are least expected to suffer it, may bear the heaviest psychological toll.

Subject of Research: Association between postherpetic neuralgia and subsequent mental disorders in a large U.S. retrospective cohort

Article Title: Mental health impact of post-herpetic neuralgia: a retrospective cohort study from 15,454 patients using TriNetX network database

Article References: Yang, M.-H., Hsiao, Y.-P., Wang, Y.-H., Huang, L.-H., Du, Y.-S., & Wu, T.-J. (2026). Mental health impact of post-herpetic neuralgia: a retrospective cohort study from 15,454 patients using TriNetX network database. BMC Psychiatry. https://doi.org/10.1186/s12888-026-08675-w

Image Credits: AI Generated

DOI: 10.1186/s12888-026-08675-w

Keywords: postherpetic neuralgia, herpes zoster, shingles, mental disorders, depression, anxiety, mood disorders, TriNetX, retrospective cohort study, propensity score matching, neuropathic pain, varicella-zoster virus