The impact of diabetes on depression treatment outcomes

Background: Individuals with diabetes mellitus (DM) are two to four times more likely to be diagnosed with major depressive disorder (MDD). However, few controlled studies have examined the impact of DM on the treatment of MDD. Understanding the effect of DM on depressed patients could provide valuable clinical information toward adjusting current treatment modalities to produce a more effective treatment for depressed patients with DM. Methods: This study was conducted using an evaluable sample of 2876 outpatient participants enrolled in the Sequenced Treatment Alternatives to Relieve Depression study. Sociodemographic and clinical characteristics and treatment characteristics with the selective serotonin reuptake inhibitor (SSRI) citalopram, as well as remission rates for MDD and time to remission, were compared between participants with DM and participants without DM. Results: The odds of remission were lower in participants with DM than in those without DM prior to adjustment [odds ratio (OR)=0.68; 95% confidence interval (95% CI)=(0.49, 0.94); P=.0184]. These differences were no longer present after adjustment [OR=0.92; 95% CI=(0.64, 1.32); P=.6399]. Participants with DM reported fewer side effects than participants without DM despite similar dosing. Conclusions: Depressed patients with DM and depressed patients without DM appear to have similar rates of MDD remission, indicating that a diagnosis of DM per se has no impact on MDD remission. The findings of fewer side effects and psychiatric serious adverse events in participants with DM imply that depressed patients with DM may be excellent candidates for more aggressive SSRI dosing. This lower prevalence of side effects reported by depressed participants with DM warrants further exploration.