Bipolar disorder and type 2 diabetes mellitus: A bidirectional relationship

Background and objectives

Over the past few decades, research has revealed complex interactions between type 2 diabetes mellitus (T2DM) and a wide range of comorbid conditions. The present paper sought to examine the relationship between bipolar disorder and T2DM and clarify the clinical impact of therapeutic interventions, highlighting the interpretation and implications of recent literature reports.

Methods

The PubMed electronic database was searched for keywords “bipolar disorder” AND “diabetes” OR “glucose”. Based on this literature search, 15 meta-analyses/systematic reviews and numerous research studies were identified that examined interrelationships between bipolar disorders and T2DM.

Results

Patients with bipolar disorder have higher rates of T2DM compared to the general population. Further, type 2 diabetic patients with comorbid bipolar disorder often experience deteriorated long-term glucose control and increased cardiovascular morbidity and mortality. Recent literature suggests shared risk factors and underlying disease mechanisms. In addition, genetic factors, sedentary life-style, lack of exercise, increased simple carbohydrate intake, adverse effects of bipolar pharmacotherapy, and bipolar depressive symptoms phenomenology may affect glucose metabolism.

Conclusions

The observed bidirectional interaction merits screening for psychiatric disorders in T2DM and vice versa to allow for early detection and treatment of this at risk population. Selection of drugs with neutral metabolic effects and dose individualization hold significant promise for optimizing therapy with antipsychotic and antidiabetic agents.