Background: Psychosis is a common feature of BD, but few studies have focused on brain volume alterations associated with psychotic symptoms in BD.
Objectives: To investigate the relation between brain volumes and psychotic symptoms in patients with BD who recently had their first manic episode.
Methods: We have recruited 50 first-episode patients with BD, according to DSM-IV-TR, and 28 healthy controls. Magnetic resonance images were used to assess whole brain measures of grey and white matter volume. History of psychotic symptoms was assessed with the MINI International Neuropsychiatric Interview. All statistical analyses were controlled for age, sex, handedness and intracranial volume.
Results: There was no significant reduction in brain volumes of patients with history of psychotic features in comparison to either non-psychotic patients or controls. However, the quantification of psychotic symptoms reported by patients was found to be negatively correlated with total grey matter volume (r=-.338, p=0.021). No significant correlation was found with total white matter or CSF volumes.
Conclusions: Our results show a negative correlation of grey matter volume and psychotic symptoms in bipolar patient early after a first manic episode. The fact that no difference in grey matter volume was observed when considering psychosis as a categorical variable suggests the need for a dimensional evaluation of psychosis. Further studies are necessary to elucidate to which extent these changes in brain volume reflect functional and cognitive impairments.