Abstract
Patients with bipolar disorders (BD) have double the risk of Type 2 diabetes mellitus (T2DM) relative to age and sex matched nonpsychiatric controls. T2DM negatively affects brain structure and function.
Participants with comorbid BD and T2DM or insulin resistance demonstrate greater morbidity, chronicity and disability, and lower treatment response to Li than euglycemic BD participants. Bipolar disorders complicated by insulin resistance/ T2DM are associated with smaller hippocampal and cortical gray matter volumes and lower levels of prefrontal N- acetyl aspartate (neuronal marker).
Importantly, the above mentioned clinical and brain changes occur already at the level of insulin resistance, which is not screened for in common clinical practice. Growing body of evidence shows that treatment of T2DM leads to preservation of brain tissue and insulin sensitizers, such as pioglitazone, improve symptoms of depression in unipolar or bipolar disorders.
These findings create a rich agenda for future research, which could enhance psychiatric pharmacopeia and directly impact patient care.