Functional MRI of verbal self-monitoring in schizophrenia: performance and illness-specific effects.

Previous small-sample studies have shown altered frontotemporal activity in schizophrenia patients with auditory hallucinations and impaired monitoring of self-generated speech. We examined a large cohort of patients with schizophrenia (n = 63) and a representative group of healthy controls (n = 20) to disentangle performance, illness, and symptom-related effects in functional magnetic resonance imaging-detected brain abnormalities during monitoring of self- and externally generated speech in schizophrenia. Our results revealed activation of the thalamus (medial geniculate nucleus, MGN) and frontotemporal regions with accurate monitoring across all participants. Less activation of the thalamus (MGN, pulvinar) and superior-middle temporal and inferior frontal gyri occurred in poorly performing patients (1 standard deviation below controls' mean; n = 36), relative to the combined group of controls and well-performing patients. In patients, (1) greater deactivation of the ventral striatum and hypothalamus to own voice, combined with nonsignificant activation of the same regions to others' voice, associated positively with negative symptoms (blunted affect, emotional withdrawal, poor rapport, passive social avoidance) regardless of performance and (2) exaggerated activation of the right superior-middle temporal gyrus during undistorted, relative to distorted, feedback associated with both positive symptoms (hallucinations, persecution) and poor performance. A further thalamic abnormality characterized schizophrenia patients regardless of performance and symptoms. We conclude that hypoactivation of a neural network comprised of the thalamus and frontotemporal regions underlies impaired speech monitoring in schizophrenia. Positive symptoms and poor monitoring share a common activation abnormality in the right superior temporal gyrus during processing of degraded speech. Altered striatal and hypothalamic modulation to own and others' voice characterizes emotionally withdrawn and socially avoidant patients.

Structural magnetic resonance imaging predictors of responsiveness to cognitive behaviour therapy in psychosis.

BACKGROUND: Responsiveness to cognitive behaviour therapy (CBT) in psychosis may have a neurological basis. This study aimed to determine whether improvement in symptoms following CBT for psychosis (CBTp) in people with schizophrenia is positively associated with pre-therapy grey matter volume in brain regions involved in cognitive processing. METHODS: Sixty outpatients stable on medication with at least one distressing symptom of schizophrenia and willing to receive CBTp in addition to their standard care (SC), and 25 healthy participants underwent magnetic resonance imaging. Subsequently, 30 patients received CBTp (CBTp+SC; 25 completers) for 6-8 months and 30 continued with their standard care (SC; 19 completers). Symptoms in all patients were assessed (blindly) at entry and follow-up. RESULTS: The CBTp+SC and SC groups did not differ clinically at baseline, and only the CBTp+SC group showed improved symptoms at follow-up. Severity of baseline symptoms was not associated with CBTp responsiveness. Reduction with CBTp in positive symptoms was associated with greater right cerebellum (lobule VII) grey matter volume, in negative symptoms with left precentral gyrus and right inferior parietal lobule grey matter volumes, and in general psychopathology with greater right superior temporal gyrus, cuneus and cerebellum (Crus I) grey matter volumes. Grey matter volume in these brain areas did not correlate with the severity of baseline symptoms. CONCLUSION: Grey matter volume of the frontal, temporal, parietal and cerebellar areas that are known to be involved in the co-ordination of mental activity, cognitive flexibility, and verbal learning and memory predict responsiveness to CBTp in patients with psychosis.