“Behaviour is the language of trauma”
– Gross K, 2022.
For decades, adverse experiences in childhood such as maltreatment or neglect, domestic violence, having a parent with a mental illness or parental separation have been recognised as key risk factors for developing psychosis later in life.
Ten years ago, a Mental Elf blog (Wood S, 2015) highlighted a review which showed that experiences of adversity in childhood were linked with the persistence of psychotic experiences later in life. With approximately 16% of adults having experienced some kind of adversity in childhood (see previous Mental Elf blog by Stock S, 2024), childhood adversity seems an ideal target for early prediction and prevention in psychosis.
Previous studies (e.g. Varese et al., 2012) have shown that those with experiences of adversity in childhood are almost three times more likely to develop psychosis than those without these experiences. The aim of a recent review by Zhou and colleagues (2025) was to investigate if this previous figure is still accurate and if different types of adversity, sex differences or the age that psychosis symptoms emerge might contribute most to this increased risk.
Childhood adversity is a key risk factor for later mental health issues, including psychosis.
Methods
The authors used six databases (PubMed, Embase, PsycINFO, Web of Science, WANFANG and China National Knowledge Internet) to search for childhood adversity and psychosis articles that were published up until February 2022.
Eligibility criteria included:
- Articles written in English, Chinese, Dutch, Italian, German, or Spanish.
- Cross-sectional, cohort or case-control studies.
- Adversity experienced before 18 years of age.
- Patients with a diagnosis of psychotic disorder, schizophrenia, or schizoaffective disorder who also provided ratings of their psychotic experiences.
Studies that only referenced drug-induced psychosis, forensic samples or the general population were excluded. The National Institute of Health (NIH) quality assessment tool was used to determine the quality of included studies.
The authors used a multilevel meta-analysis to pool all of the available data from the studies and provide an estimate of the overall association between of childhood adversity and psychosis. They also explored the relationship between the type of adversity experienced and psychosis, any differences between male and female participants and the effect of adversity on the age psychosis symptoms first occurred.
Results
From the literature search, 54,553 relevant records were found. From this, the authors examined 1,546 full text articles. In total, two hundred and four studies were included in this review, with a total of 349,468 participants (50% female) and a mix of study designs (65% case-control, 28% cross-sectional and 7% cohort).
Overall Association: Childhood Adversity and Risk of Psychosis (183 studies)
People who suffered childhood adversity were almost three times more likely to develop psychosis than those who did not suffer from adversity (odds ratio (OR) = 2.80, 95% CI [2.18 to 3.6]).
The strength of the relationship differed depending on the type of study used. Case-control studies, for example, showed that those with adversity had a larger risk of psychosis compared to those without (3.49, 95% CI=3.06 to 3.99). This risk was bigger than the effect shown in cross-sectional studies, but not as different to that shown in cohort studies. As cohort studies tend to be more reliable in identifying causal relationships, the similarity in effect sizes between these studies and the case-control studies suggests that childhood adversity may play a causal role in the development of psychosis later in life.
Specific Adversity Subtypes (167 studies)
The authors looked at 12 different types of childhood adversity. People who experienced any type of adversity had overall a greater chance of developing psychosis or psychotic symptoms, compared to those who did not experience adversity.
People who specifically experienced emotional abuse had the highest chance of developing psychosis (OR 3.54, 95% CI [3.04 to 4.13]).
Those who experienced parental antipathy (a form of emotional abuse stemming specifically from one’s parent) had the lowest (but still increased) risk of developing psychosis (OR 1.58, 95% CI [1.48 to 1.68]).
Sex Differences (40 studies)
No differences were found between males and females in the association between childhood adversity and psychosis. This means that both men (OR 2.48) and women (OR 2.62) have a similar likelihood of developing psychosis if they have experienced childhood adversity.
Age of Psychosis Onset (16 studies)
Patients who experienced childhood adversity developed psychosis approximately 9.5 months earlier than those who did not experience adversity (−0.79, 95% CI [−1.47 to −0.12]).
People affected by childhood adversity face nearly three times the relative risk of developing psychosis.
Conclusions
The authors conclude that this study:
confirms the increased risk of psychosis among individuals exposed to adversities early in life.
This means that people who experience adversity in childhood are almost 3 times more likely to develop psychosis in later life than those without such negative experiences. This increased risk was evident across at least nine types of childhood adversity, particularly emotional abuse, which has been frequently shown to be associated with psychosis in previous studies. Childhood adversity-exposed individuals were also shown to have experienced their first psychotic episode appropriately 9.5 months earlier compared to unexposed individuals.
Trauma speeds up onset: psychosis starts earlier in those exposed to childhood adversity.
Strengths and limitations
This study is the largest meta-analysis to date on the association between childhood adversity and psychosis, enabling a synthesis of the evidence and strong reliability of findings. It is also the first meta-analysis to investigate potential sex differences in the effects of childhood adversity on psychosis risk and the first to link this adversity to variations in the age of onset of psychosis symptoms.
Some limitations are of note. Some characteristics of childhood adversity were not considered, such as whether the adversity was ongoing and for how long the adversity was experienced. Additionally, other important aspects to consider include the relationship of perpetrator to the child and how much of an impact the trauma had on the child. Such details could potentially affect the strength of the relationship between childhood adversity and psychosis, as well as provide further insight into the mechanisms behind the relationship (i.e. how does childhood adversity increase the risk of psychosis?). As acknowledged by the authors, there was insufficient data for some sub-types of childhood adversity such as discrimination and the authors noted that different subtypes of adversity were reported for males and females. Not only did this mean that some studies had to be excluded from the analyses that explored sex differences in the adversity-psychosis relationship, but this could also have resulted in some of the effects being under-reported. For example, there was little evidence that sexual and physical abuse were related to psychosis in men. The authors acknowledged that this finding could be attributed to the limited number of studies that were included in these analyses. Moreover, the current review observed significant heterogeneity across the studies and several included studies did not account adequately for important confounding factors. A more standardised, methodological approach would help to discern more comparable findings.
Importantly, childhood adversity was measured as a “chunk of time.” The developmental timing of the adversity could be a crucial factor in determining later impact and for more strategic early interventions (Dunn et al., 2013; Murphy et al., 2025). Furthermore, significant publication bias was also found for some of the analyses, meaning that some effect sizes could be subject to inflation. Lastly, it is unclear whether in addition to self-report, parental reports of adversity experienced by their child were used. There are often substantial differences in how the adversity is reported or described by the parent and by the child themselves. Parental reports may under-report or minimise the impact of the adversity experienced by the child due to feelings of guilt or shame, or fear of repercussions. This can greatly affect the accuracy of the findings (Skar et al., 2021).
Not just if, but when trauma happens may influence mental health outcomes.
Implications for practice
Several key clinical interpretations can be pulled from this review.
Firstly, people with childhood adversity are at an increased risk for psychosis, irrespective of being male or female or the types of adversity that they experienced. Other studies have also shown that people with childhood adversity have an increased risk of developing depression and bipolar disorder. Collectively, the evidence shows how important it is to consider the influence of environmental exposures when considering a person’s risk for later mental health challenges. We need to consider approaches such as trauma-informed care, where instead of asking the question “what’s wrong with you?”, we ask “what has happened to you?”. Trauma-informed care involves gathering a complete picture of a person’s life, which helps service providers to then tailor care to meet the individual’s needs in a more holistic manner and has been linked to improved outcomes of mental health disorders such as psychosis.
The review also showed that people who had experienced emotional abuse and neglect had the highest increased risk for developing psychosis later in life compared to the other types of adversity. Abuse and neglect are fundamentally different psychological experiences and therefore differ in their impact on both the risk of psychosis, as well as its symptoms. There are also differences in how the person recognises and understands emotional cues, challenges with socio-emotional adjustment, as well as variations in brain development – all which create a heightened vulnerability for later mental health challenges. In line with the idea of trauma-informed care, this increased understanding of the impact that different types of adversity can have on psychosis could be beneficial in terms of psychosis treatment, enabling the development of tailored treatment plans and more specialised trauma-focused therapy.
Secondly, psychosis symptoms emerged approximately 9.5 months earlier in people with childhood adversity compared to those without this trauma. This really emphasises the importance of early identification of and intervention for psychosis in people with a history of childhood adversity. The provision of early intervention in psychosis holds a key position in mental health care both in Ireland and indeed worldwide. With outcomes ranging from reduced severity of symptoms and less overall hospitalisations, it is important that policy makers continue to be informed about the benefits of these programmes, so that we can maximise the availability of these services.
However, while this review article is striking in its confirmation of the relationship between early adversity and psychosis, it is not possible to determine definite causal pathways as the studies included information that was taken from one point in time and also used self-reported data. Future well-powered longitudinal studies would help to develop a better understanding of the underlying causal mechanisms linking childhood adversity and psychosis so that we can better focus on targeted prevention and treatment techniques.
We need better long-term studies to understand how childhood trauma leads to psychosis – and how to prevent it.
Statement of interests
I have no conflicting interests to express.
Links
Primary paper
Zhou L, Sommer IEC, Yang P, et al. (2025) What Do Four Decades of Research Tell Us About the Association Between Childhood Adversity and Psychosis: An Updated and Extended Multi-Level Meta-Analysis. American Journal in Psychiatry. 182(4):360-372. [PubMed abstract]
Other references
Dunn E C, McLaughlin K A, Slopen N, et al. (2013) Developmental timing of child maltreatment and symptoms of depression and suicidal ideation in young adulthood: results from the National Longitudinal Study of Adolescent Health. Depression and anxiety (PDF), 30(10), 955–964.
Gross K. (2022). Behavior is the language of trauma. Medium. [last accessed 19 May 2025]
Murphy J, Healy C, Mongan D, et al. (2025). Developmental stage of childhood trauma exposure and markers of inflammation at age 24 (PDF). Brain Behavior and Immunity. 126, 225-234.
Skar A S, Jensen T K, and Harpviken A N. (2021) Who Reports What? A Comparison of Child and Caregivers´ Reports of Child Trauma Exposure and Associations to Post-Traumatic Stress Symptoms and Functional Impairment in Child and Adolescent Mental Health Clinics. Research on child and adolescent psychopathology (PDF). 49(7), 919–934.
Stock, S. Adverse childhood experiences: how common are they and who is most at risk? The Mental Elf, 15th Jan 2024.
Varese F, Smeets F, Drukker M, et al. (2012) Childhood adversities increase the risk of psychosis: a meta-analysis of patient-control, prospective- and cross-sectional cohort studies (PDF). Schizophrenia Bulletin. 38(4).
Wood, S. Childhood adversity and psychotic symptoms: how much can a growing evidence-base tell us? The Mental Elf, 14th Sep 2015.
