Effects of childhood trauma on working memory in affective and non-affective psychotic disorders

Abstract

Childhood trauma is a significant risk factor for the development of psychotic disorders, and may influence executive brain functions. We thus set out to investigate the long-term effects of childhood trauma exposure on brain function of adult chronic patients diagnosed with schizophrenia, schizoaffective disorder and (psychotic) bipolar-I disorder while performing a standard 2/0-back working memory task. Participants were 50 cases diagnosed with schizophrenia/schizoaffective disorder (SCZ), 42 cases with bipolar-I disorder (BD), and 47 healthy controls (HC). Among this sample, 56 clinical cases (SCZ = 32; BD = 24) and 17 HC reported significant levels of childhood trauma, while 36 clinical cases (SCZ = 18; BD = 18) and 30 HC did not. Effects of childhood trauma on working memory-related brain activation were examined in combined samples of clinical cases (independently of diagnosis) relative to HCs, as well as within each diagnostic category. Case-control analyses revealed increased activation of the left inferior parietal lobule as a main effect of trauma exposure. In addition, trauma exposure interacted with a diagnosis of SCZ or BD to reveal trauma-related increased activation in the cuneus in clinical cases and decreased activation in this region in controls. Disorder-specific functional alterations were also evident in the SCZ sample, but not BD. Childhood trauma exposure elicits aberrant function of parietal regions involved in working memory performance regardless of clinical status, as well as task-relevant visual regions that participates to attentional processes. Childhood trauma may therefore contribute to alterations in attention in SCZ and BD while performing an n-back working memory task.

Keywords: Bipolar-I disorder; Childhood trauma; Functional magnetic resonance imaging; Psychosis; Schizophrenia; Working memory.