Childhood trauma and hippocampal-dependent memory across the psychosis spectrum: a systematic review and meta-analysis.

Abstract

Background: Although the processes underlying the relationship between developmental trauma and psychosis remain to be elucidated, alterations in hippocampal-dependent memory (HDM) processing may underlie this relationship. We hypothesized that exposure to developmental trauma would be negatively associated with HDM and hippocampal volume and positively associated with intrusive memories among people with psychosis.

Methods: We conducted a systematic search of studies published from Dec. 18, 2020, to Nov. 14, 2023, using the search terms "childhood," "trauma," "psychosis," and "memory processing" in Embase, PsycINFO, MEDLINE, OpenGrey, Google Scholar, and PTSDpubs. We conducted meta-analyses of studies that measured developmental trauma (self-report questionnaires or interviews), HDM (episodic memory performance and trauma-memory intrusions), semantic and recognition-memory performance, and hippocampal volume among people with psychosis. Subsample analysis determined whether these associations differed across the psychosis spectrum or for specific abuse types.

Results: We included 26 studies. Meta-analyses found that developmental trauma was not associated with total hippocampal volume (n = 4, outcomes = 6, d = -0.12, standard error [SE] = 0.20, p = 0.2), episodic memory performance (n = 10, outcomes = 42, d = 0.11, SE = 0.19, p = 0.5), recognition (n = 3, outcomes = 4, d = -0.55, SE = 0.58, p = 0.3), or semantic memory performance (n = 4, outcomes = 6, d = 0.08, SE = 0.13, p = 0.6) in participants across the psychosis spectrum. One study found that developmental trauma was associated with impaired episodic memory performance in participants with schizotypal disorder and participants with a mixed phenotype of affective and psychotic symptoms. Two studies found developmental trauma to be associated with increased involuntary memory intrusions in a sample of people with psychosis.

Limitations: We did not control for age of trauma, sex, or chronicity of trauma. Results should be considered with caution, given the high publication bias and study heterogeneity seen within meta-analyses.

Conclusion: The association between developmental trauma and memory processing may not affect HDM more than the psychotic symptoms already experienced by affected individuals. However, future studies should focus on the effects of developmental trauma on involuntary memory among people with psychosis.