Childhood Trauma in Schizophrenia Spectrum Disorders: A comparison to substance abuse disorders, and relation to cognitive performance and antipsychotic treatment outcomes

Abstract

An increasing body of research points to the importance of childhood trauma (CT) in psychosis, and as a risk factor for schizophrenia spectrum disorders (SSDs). The aim of this thesis was to investigate and compare the frequency and severity of CT in relation to clinical aspects and treatment outcomes in SSDs. The Childhood Trauma Questionnaire Short-Form (CTQ-SF) was used to retrospectively measure overall exposure to CT and CT subtypes (physical, sexual, and emotional abuse, and physical and emotional neglect).

Paper I examined the specificity of CT in SSDs, and showed no group differences between patients with SSDs and patients with substance use disorders (SUDs) when comparing CTQ-SF sum and subscale scores, as well as no differences in the frequency and severity in the reported CT. Paper II examined the potential effect of CT on cognition in SSDs. No overall group differences emerged between SSD patients with CT compared to those reporting no CT. However, the CT subtype physical neglect predicted impaired attention/working memory abilities in SSDs. Paper III examined the influence of CT on general and differential antipsychotic effectiveness in SSDs. There were no differences for general antipsychotic effectiveness at 52 weeks for SSDs patients with CT as compared to the no CT group. However, for the olanzapine subgroup, the CT group showed less decrease in overall psychosis symptoms form baseline to 12, 26, 39 and 52 weeks.

Findings from the current thesis suggest that CT is frequently reported in SSDs, although not unique nor specific for SSDs in comparison to SUDs. The CT subtype neglect appears to be related to clinically relevant features associated with SSDs such as cognitive performance, possibly reflecting a cognitive vulnerability for psychosis. Additionally, our findings indicate that CT may be associated with a slower antipsychotic treatment response to olanzapine in SSDs, even though the overall effect of CT was minimal. Clinicians and patients with SSDs and SUDs could benefit from integrating information regarding CT exposure in routine clinical settings.