Complex post-traumatic stress disorder moderates functional connectivity in people with psychosis

Altered functional connectivity in several functional networks has been found in people with psychosis, especially in the default mode (DMN), salience (SAL) and central executive (CEN) networks. Functional connectivity in people with psychosis is influenced by traumatic life experiences. Trauma histories typical of people with psychosis are associated with complex post-traumatic stress disorder (cPTSD), but no studies have explored whether post-traumatic sequelae contribute to functional dysconnectivity in people with psychosis.

Using resting-state fMRI, we compared two groups meeting diagnostic criteria for schizophrenia spectrum disorders (N = 106); one group additionally met ICD-11 criteria for comorbid cPTSD, whereas the other did not. We assessed between-group differences in functional connectivity between 15 pre-defined regions of the DMN, SAL and CEN. Post-hoc correlations were used to test whether intra- and/or inter-network connectivity related to cPTSD symptom severity in the comorbid cPTSD group.

The comorbid cPTSD group demonstrated significantly lower functional connectivity within the DMN, SAL and CEN, as well as increased negative connectivity between the SAL and CEN. The control group showed significantly decreased connectivity of the DMN with the SAL and CEN. PTSD symptoms correlated positively with intra-SAL connectivity and DMN-SAL dysconnectivity, whereas DSOs correlated positively with intra-SAL dysconnectivity and reduced DMN-CEN connectivity.

Our findings broadly align with the tripartite network model explaining psychopathology in terms of DMN, SAL and CEN dysconnectivity. Intra-network dysconnectivity in subgroups of people with psychosis may relate to post-traumatic sequelae, whereas inter-network dysconnectivity may be more central in trauma-unrelated psychoses.