Reduced frontal cortex inositol levels in postmortem brain of suicide victims and patients with bipolar disorder

OBJECTIVE: This study aimed to evaluate aspects of second messenger function in the brain of suicide victims and patients with bipolar disorder. METHOD: Inositol and its synthetic enzyme, inositol monophosphatase, were measured in postmortem brain samples of 10 suicide victims, eight patients with bipolar affective disorder, and 10 normal comparison subjects. RESULTS: The frontal cortex inositol levels of the suicide victims and the patients with bipolar disorder were significantly less than those of the normal comparison group. No differences in cerebellum or occipital cortex inositol levels were found among the three groups. The groups also showed no differences in inositol monophosphatase activity in any brain area. CONCLUSIONS: These results could suggest a deficiency of second messenger precursor in patients with bipolar disorder and suicide victims.