In one of my first blogs for The Mental Elf, I reported on a systematic review and meta-analysis of the association between exposure to childhood maltreatment and later mental and physical ill health. That demonstrated a link between physical abuse, emotional abuse, and neglect, with poor mental and physical health outcomes.

Furthermore, the association between child sexual abuse and poor psychological health in adult life is now well established (Andrews et al, 2004). Research is now studying the extent to which childhood adversity is associated with persistence of symptoms or disorder, particularly in psychosis.

In this systematic review and meta-analysis published recently in Psychological Medicine (Trotta et al, 2015), the impact of childhood adversity on psychotic experiences and symptomatic outcomes from clinical states is examined.

Methods

The authors conducted a systematic review of all publications in Medline, EMBASE and PsychINFO databases up to the end of November 2014 that investigated childhood adversity, psychosis, and course of psychotic experiences and symptoms.

Childhood adversity was defined as maltreatment, victimization, parental loss or separation, war-related trauma, natural disasters, and witnessing violence.

Publications were included only if they had sufficient follow-up data to judge psychotic experience or symptomatic outcome – unfortunately for generalisability, articles in languages other than English were excluded.

From this search, 20 studies were eligible for inclusion:

• 9 assessing the general population
• 3 the ultra-high risk state
• 4 first-episode psychosis
• 4 non-first episode patients

However, only 13 were regarded as methodologically robust on the basis of a quality assessment score.

Results

• In general population samples, there was some evidence of an association between persistence of psychotic experiences and childhood adversity. Only one of these papers failed to show such an association.
• In ultra-high risk samples, the main outcome variable was transition to psychosis rather than persistence of subthreshold symptoms. All three studies suggested increased risk of transition in those with a history of childhood adversity, which may be specific to sexual trauma.
• In patients with frank psychotic disorder the results were more mixed, with some positive associations and some negative. This may be due to the overall small numbers in these studies, or the focus on different measures of adversity or outcome making comparison difficult.
• A meta-analysis was conducted on those papers that reported odds ratios (OR) between childhood adversity and persistence of psychotic symptoms:
  • This suggested a significantly elevated risk of symptom persistence in those with a history of childhood adversity in the general population (OR 1.76, CI 1.19 to 2.32; 5 studies)
  • However, there was significant heterogeneity between these papers, suggesting there may be problems combining them. While the OR in clinical groups was similar (OR 1.55), the confidence interval included 1 (CI 0.32 to 2.77) suggesting this was non-significant. There is confusion on this point though, because the authors state that this was actually significant (p=0.007).

Strengths and limitations

The authors have covered the spectrum of psychotic symptomatology, from non-clinical experiences in the general population, through ultra-high risk individuals, to those with frank psychosis.

However, there are several serious limitations:

• The main one, acknowledged by the authors themselves, is that there is huge variability in definitions of childhood adversity, and in their method of assessment, making comparisons between studies in the review extremely difficult and of limited value.
• The meta-analysis is also problematic. Only 9 studies could be included, but only a third of them were methodologically acceptable by the authors’ own measure. There is also some confusion about the significance of one of the results mentioned above, which reduces the value of the analysis.
• Finally, when reviewing the three studies of ultra-high risk patients, the authors did not notice that two of the three are actually reporting the same population, with different follow-up intervals.

Conclusion

The authors appropriately note that the evidence to date is methodologically limited, but that is of sufficient value to tentatively support a role for childhood adversity in the course of psychotic phenomena.

While this has potential value for understanding the mechanisms by which psychotic phenomena persist, from an intervention perspective it is not clear that this adds very much beyond what we already know.

Reducing childhood adversity will have enormous mental health benefits and needs significant effort now.

Links

Primary paper

Trotta A, Murray RM, Fisher HL. The impact of childhood adversity on the persistence of psychotic symptoms: a systematic review and meta-analysis. Psychol Med 2015 Apr 23:1-18. [PubMed abstract]

Other references

Andrews et al (2004) Child sexual abuse. In Comparative quantification of health risks: global and regional burden of disease attributable to selected major risk factors (Ezzati et al, editors). WHO, Geneva; pp 1851-1940