Altered Neural Activation in First Episode Psychosis Patients With Comorbid Conduct Disorder: A Pilot Investigation

Most individuals with psychosis do not perpetrate violence. However, conduct disorder (CD) increases the risk of violence in psychotic conditions. Because it is currently unknown whether the neural correlates of first-episode psychosis (FEP) differ when CD is present, we used functional magnetic resonance imaging (fMRI) during a Go/No-Go impulsivity paradigm to investigate. Based on previous research, we hypothesized that activation differences between FEP and FEP+CD would be found in the prefrontal cortex, cingulate cortex, and inferior parietal lobule.

We scanned 51 male participants: 17 FEP, 16 FEP+CD, and 18 healthy controls with an average age of 24.2 years (range, 17-34 years). Whole-brain images were analyzed via a general linear model, and first-level contrast images were created comparing successful No-Go > Go trials. Paired t tests were conducted at the group level and included confound regressors for age, IQ, antipsychotic dose, psychotic symptoms, and framewise displacement. A voxel-based Z-score threshold of Z > 3.1 (p < 0.001, uncorrected) and a cluster-level extent threshold of p <0.01, corrected, was considered significant.

Successful response inhibition elicited hyperactivation in FEP+CD vs FEP in the cingulate gyrus; regions of the PFC, including right middle frontal gyrus (RMFG); bilateral inferior parietal lobule; temporal gyrus; and cerebellum (p values ranged from 1.11E-08 to 0.0031). There was no region in which activation was greater in FEP > FEP+CD.

These preliminary results tentatively suggest that brain regions subserving response inhibition may be altered when CD is comorbid with FEP.