The Role of Childhood Trauma in Psychosis and Schizophrenia: A Systematic Review

Abstract

Schizophrenia (SCZ) is a prevalent cause of disability worldwide. Distinguished mainly by psychosis, behavioral alterations could range from hallucinations to delusions. This systematic review examines evidence of a relationship between childhood trauma/adverse life events and psychosis, especially in SCZ. A methodical search provided reproducible results using these five databases: PubMed, ScienceDirect, Semantic Scholar, JSTOR, and Cochrane Library. The systematic search focused on articles published between July 2016 and July 2021. The search strategy utilized specific keywords relevant to SCZ, psychosis, and childhood trauma. The formulation of specified inclusion and exclusion criteria was necessary to ensure a comprehensive narrowed-down search, such as the inclusion of free full-text articles published or translated in English and exclusion of irrelevant subject areas. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a strategic search initially identified 741 articles; three additional articles were identified from citation searching. After relevance screening, duplicate removal, and quality appraisal, 12 studies from databases/registers and three from citation searching met the criteria proving relevance to our review with minimal evidence of bias. The final selected 15 studies included observational studies and reviews. A review of relevant data unveiled findings on childhood adversity, individual lived experiences, and their involvement in SCZ. Evidence suggests that certain neurobiological processes occur in brain after trauma. The inflammation and dysregulation from oxidative stress predispose patients to an at-risk-mental state, facilitating the progression to SCZ. This review encourages further evaluation of early trauma detection and the potential benefits of early intervention.

Increased blood neutrophil extracellular traps (NETs) associated with early life stress: translational findings in recent-onset schizophrenia and rodent model

“…Our exploratory analyses suggested that forms of neglect (emotional and physical) together with emotional abuse were the subtypes mostly contributing to cluster separation. This is consistent with evidence showing that the prevalence of child neglect is around 78% in the general population, while physical and sexual abuse are reported in around 18% and 9% [87].…”

Clinical and Biological Overlap between Schizophrenia, Autism Spectrum Disorder, and Trauma and Stress-Related Disorders: The Three-Tree Model of SCZ-ASD-TSRD

“…Childhood trauma experiences are also associated with the degree of symptoms, with higher levels of trauma being associated with more positive symptoms, depressive symptoms, and lower levels of cognitive functioning. Childhood trauma experiences are associated more with positive symptoms, such as hallucinations and delusions, than with negative symptoms [5]. Childhood trauma induces dissociation, where stronger childhood trauma experiences are reflected by higher scores on the Dissociative Experiences Scale (DES), which measures dissociation.…”

“…Positive symptoms have also been shown to correlate positively with DES scores in SCZ patients [28]. Indeed, some researchers have proposed the idea that symptoms such as hallucinations and delusions reflect a personal perception of intrusion that leads to a sense of hopelessness [5]. Furthermore, it is worth noting that the direction of Schneider's first-class symptoms, which were historically considered important symptoms of SCZ, are more common in patients with dissociative identity disorder than in those with SCZ [29].…”

“…Notably, it has recently become widely recognized in clinical practice that some of the symptoms of SCZ (especially negative symptoms) and ASD share similarities [4]. Trauma-and stress-related disorders (TSRDs) are a group of emotional and behavioral problems that result from childhood trauma and stress experiences, which have also received attention as disorders that exhibit symptoms similar to those of SCZ, especially the positive symptoms of SCZ [5]. Traumatic and stressful experiences that cause TSRD include exposure to physical and emotional violence and distress, such as abuse and neglect.…”

A scoping review of trauma informed approaches in acute, crisis, emergency and residential mental health care

“…Research has shown that individuals engaged with mental health services report high levels of childhood and adulthood trauma (2, 8–10). There is a high prevalence of trauma among service users in acute services, including among women (2, 11), those with psychosis (12, 13), and “personality disorder” diagnoses (14) (which is a particularly controversial diagnosis (15) as a result of the stigma associated with this diagnostic label and disparities in quality of care experienced (16–19)). Electronic health record evidence shows that service users with a history of abuse during childhood have more comorbidities and are more likely to have inpatient admissions versus service users without a similar history (20).…”