Hypothalamic subunit volumes in schizophrenia and bipolar spectrum disorders

Abstract BackgroundThe hypothalamus is central to many hormonal and autonomous nervous system pathways. Emerging evidence indicates that these pathways may be disrupted in schizophrenia and bipolar disorder. Yet, few studies have examined the volumes of hypothalamic subunits in these patient groups. We compared hypothalamic subunit volumes in individuals with psychotic disorders to healthy controls. Study DesignWe included 344 patients with schizophrenia spectrum disorders (SCZ), 340 patients with bipolar disorders (BPD) and 684 age-and-sex-matched healthy controls (CTR). Total hypothalamus and five hypothalamic subunit volumes were extracted from T1-weighted MRI using an automated Bayesian segmentation method. Regression models, corrected for age, age2, sex, and segmentation-based intracranial volume (sbTIV), were used to examine diagnostic group differences, interactions with sex, and associations with clinical symptoms, antipsychotic medication, antidepressants and mood stabilizers. Study ResultsSCZ had larger volumes in the left inferior tubular subunit and smaller right anterior inferior, right anterior superior and right posterior hypothalamic subunits compared to CTR. BPD did not differ significantly from CTR for any hypothalamic subunit volume, however, there was a significant sex-by-diagnosis interaction. Analyses stratified by sex showed smaller right hypothalamus and right posterior subunit volumes in male patients, but not female patients, relative to same-sex controls. There was a significant association between BPD currently taking antipsychotic medication and the left inferior tubular subunits volumes. ConclusionsOur results show regional-specific alterations in hypothalamus subunit volumes in individuals with SCZ, with relevance to HPA-axis dysregulation, circadian rhythm disruption and cognition impairment. HighlightsSmaller right anterior-inferior, right anterior superior, right posterior and larger left inferior tubular subunit volumes were observed in individuals with schizophrenia spectrum disorders compared to healthy controls.Smaller total right hypothalamus volume and smaller right posterior subunit volumes were found for males, but not females, with bipolar disorders.There were no significant associations with clinical symptom dimensions.Larger left inferior tubular subunits volumes were observed in individuals with bipolar disorders currently taking antipsychotic medication.