When Baby Won’t Stop Crying: Stress and Temperament Shape Mother-Infant Bonding

Every parent knows the feeling: the baby who cries for hours, refuses to sleep, or turns away from food, leaving exhausted mothers and fathers questioning everything they do. Now, new research from Germany offers one of the most detailed looks yet at what happens to the emotional bond between mothers and infants when these early regulatory problems become clinical disorders. The study, published in Frontiers in Developmental Psychology, followed 119 mothers of infants diagnosed with excessive crying, sleeping, or eating disorders according to the DC:0-5 classification system, the gold standard for diagnosing mental health conditions in children under five. Its central finding is striking in its simplicity: when it comes to bonding difficulties, two factors rise above all others as independent predictors—parenting stress and the infant’s capacity for effortful control.

Regulatory problems are far from rare. In the first year of life, roughly 20 to 30 percent of infants show difficulties in at least one of the three domains of crying, sleeping, or eating. Excessive crying is typically defined by the Wessel criterion, known as the rule of three: crying for at least three hours per day, on at least three days per week, for a minimum of three weeks. Sleep onset disorder involves a latency exceeding 30 minutes on most nights, while night waking disorder describes multiple or prolonged awakenings. Undereating disorder is characterized by reduced food intake relative to age, often accompanied by lack of interest in food, selective eating, or difficulties transitioning to solid foods. These problems are among the most common mental health diagnoses in the first three years of life, and they carry long-term consequences, with research linking early regulatory problems to increased risks of behavioral and mental disorders later in childhood and even adulthood.

The research team, led by Jennifer Mrakovits of the Technical University of Munich and kbo-Kinderzentrum Munich, recruited families from a socio-pediatric clinic in Southern Germany. The infants ranged in age from under one month to nearly two years, with an average of about 11 months. Most had been diagnosed with a single disorder, though nearly 40 percent carried two diagnoses and a small number had three. Sleep disorders were the most prevalent, followed by feeding and crying disorders. The mothers completed a battery of validated questionnaires measuring bonding through the Postpartum Bonding Questionnaire, mentalizing abilities through the Parental Reflective Functioning Questionnaire, parenting stress through the Parenting Stress Index, and psychological symptoms through the Symptom-Checklist-90. Infant symptom severity was captured with the Questionnaire for Crying, Feeding, and Sleeping, while temperament was assessed with standardized instruments covering three dimensions: negative affect, surgency, and effortful control.

Bonding, in this context, refers to the degree to which a mother shows positive emotions, cognitive appraisals, and supportive actions toward her infant. It begins during pregnancy and gradually strengthens through early childhood, forming a central context for the development of the infant’s self-regulation. Impaired bonding manifests in feelings of irritability, hostility, or a sense of rejecting the child. Because infants depend on caregivers for co-regulation of arousal, emotion, attention, and behavior, disruptions in this emotional relationship can interfere with the very process through which babies learn to manage their internal states. Previous research has linked weaker bonding to more frequent regulatory problems, higher colic ratings, and increased sleep difficulties, creating the possibility of a self-reinforcing cycle between infant dysregulation and relational strain.

The correlational results painted a broad picture. Greater bonding problems were associated with higher levels of a pre-mentalizing mode, in which mothers interpret infant behavior as hostile or inexplicable rather than as reflecting underlying mental states. Bonding difficulties also correlated with lower certainty about mental states, elevated parenting stress, and increased psychopathology. On the infant side, bonding problems were related to increased crying and sleeping difficulties, lower effortful control, and lower surgency, a temperament dimension reflecting approach behavior and positive reactivity. Notably, negative affect—the fussiness and irritability that define a difficult temperament—just barely failed to reach statistical significance in its association with bonding, a pattern the authors suggest may reflect the specific clinical character of the sample.

But the regression analysis told a more selective story. When all maternal and infant variables were entered simultaneously, only two emerged as significant independent predictors of bonding impairment: parenting stress and infant effortful control. Parenting stress carried a positive association, meaning higher stress predicted greater bonding problems, while effortful control showed a negative association, meaning infants with lower capacity for voluntary, top-down regulation of attention and behavior had mothers with greater bonding difficulties. The model explained a substantial portion of the variance in bonding scores, and a post-hoc power analysis indicated very high statistical power. The authors interpret this pattern as suggesting that proximal, interaction-related factors may be more directly tied to bonding than broader maternal psychological characteristics such as general symptom burden.

Further analyses added a mediation component. Infant effortful control was significantly associated with parenting stress, which in turn was associated with bonding problems. An indirect effect of effortful control on bonding through parenting stress was observed, indicating significant mediation. Yet the direct effect of effortful control on bonding remained significant even after accounting for this pathway, indicating partial mediation. In practical terms, this suggests that infants with limited self-regulatory capacity may increase the emotional and cognitive burden of caregiving, which then elevates the risk of bonding difficulties. At the same time, the infant’s temperament appears to shape bonding experiences through additional routes beyond stress alone, possibly through the day-to-day quality of interactions and the transactional dynamics within the mother-infant relationship.

The clinical implications are considerable. Mothers of infants with regulatory disorders may be particularly vulnerable to bonding difficulties because the infant’s signals can be difficult to interpret. Repeated unsuccessful attempts to soothe a crying baby can generate physical and emotional exhaustion, leading to feelings of helplessness, guilt, and frustration that interfere with the development of positive feelings toward the child. High stress levels in parents are also associated with a higher likelihood of maladaptive responses to excessive infant crying, which in extreme cases may include aggressive behaviors with serious consequences. The authors emphasize that early interventions, such as infant-parent psychotherapy, should address maternal bonding explicitly. Approaches that enhance parents’ curiosity about their infants’ inner world, such as mentalization-based group interventions, may be particularly promising, as may early support targeting parental sensitivity and stress management.

Psychoeducation emerges as another key application. The causes of early regulatory problems remain poorly understood, and parental guilt about their origins is a salient concern for families. The findings suggest that parents can be informed that early regulatory difficulties may reflect an underlying biological disposition, such as limited effortful control, while also being shaped by parent-infant interaction processes and parental psychosocial stressors. Emphasizing this multifactorial perspective may alleviate parental burden and reduce shame, reframing regulatory problems as challenges within the caregiving relationship rather than as results of parental failure. Importantly, the authors distinguish between effortful control, which reflects a relatively stable temperamental trait, and regulatory problems, which are observable, domain-specific difficulties that may vary across contexts and developmental stages.

The study is not without limitations. The cross-sectional design precludes causal conclusions, and bidirectional effects cannot be ruled out—it is conceivable that bonding impairment might negatively affect parenting stress and infant self-regulation in terms of a vicious cycle. The sample consisted predominantly of highly educated, German-speaking mothers in stable partnerships, which may limit generalizability, and the absence of a control group makes it difficult to determine how specific these bonding difficulties are to infants with regulatory disorders. All variables apart from the clinical diagnoses were assessed by maternal self-report, raising the possibility that mothers with higher bonding problems perceive their infant’s development more negatively. Fathers were not investigated, despite evidence that paternal bonding and mental health are closely linked to children’s developmental outcomes. Future studies should employ longitudinal designs, include more diverse samples, incorporate objective measures of temperament and parent-infant interaction, and investigate fathers. Still, as the first study to examine bonding in infants diagnosed with excessive crying, sleeping, or eating disorders according to DC:0-5, the work marks a significant step toward understanding how maternal stress and infant temperament jointly shape the earliest emotional relationships—and how supporting both sides of the dyad may protect the foundations of lifelong mental health.

Subject of Research: Developmental Psychology

Article Title: Maternal bonding in mothers of infants with excessive crying, sleeping, and/or eating disorders: the role of maternal stress and infant temperament

Article References: Mrakovits, J., Mall, V., & Licata-Dandel, M. (2026). Maternal bonding in mothers of infants with excessive crying, sleeping, and/or eating disorders: the role of maternal stress and infant temperament. Frontiers in Developmental Psychology, 4, Article 1831323. https://doi.org/10.3389/fdpys.2026.1831323

Image Credits: AI Generated

DOI: 10.3389/fdpys.2026.1831323

Keywords: maternal bonding, infant temperament, parenting stress, regulatory problems, excessive crying, mentalization, child development, Maternal, bonding, mothers, infants, excessive