Suicide rates for those with depression elevated regardless of diabetes diagnosis

Rates for suicide and mortality were elevated for patients diagnosed with major depressive disorder regardless of timing for diagnosis of type 2 diabetes, according to a longitudinal study published in the Journal of Clinical Psychiatry.

“Depression in [diabetes mellitus] is associated with low-quality self-care behaviors, suboptimal glycaemic control, reduced quality of life, incident microvascular and macrovascular diseases and elevated mortality,” Chun-Jen Huang, MD, MPH, PhD, of the department of psychiatry at Kaohsiung Medical University Hospital in Taiwan, and colleagues wrote. “Because patients with MDD generally exhibit poor self-care, lack of medication compliance and neglect of diet and exercise, patients with MDD and [type 2 diabetes mellitus] may have increased diabetic complications and higher mortality.”

Huang and colleagues sought to investigate whether any differences existed in the rates of both suicide and all-cause mortality in Taiwanese patients diagnosed with MDD and type 2 diabetes mellitus (T2DM) depending on which was initially diagnosed.

The researchers culled data from a longitudinal administrative claims database, which yielded a representative random sample of 2 million national health insurance beneficiaries, as well as from national death registry data from 2000 through 2015. They divided patients with newly diagnosed T2DMinto subgroups: MDD before T2DM, T2DM without diagnosis of MDD (from which they selected matched controls), and MDD after T2DM. Huang and colleagues analyzed data from 157,426 patients without MDD, 2,681 patients with MDD before T2DM and 5,174 patients with MDD after T2DM.

The first matched cohort featured 2,638 patients with MDD before T2DM and 10,552 matched control patients. The second matched cohort included 5,114 patients with MDD after T2DM and 20,456 matched control patients.

Results showed that significantly higher risks for all-cause mortality existed for both MDD before T2DM and MDD after T2DM groups (adjusted HR=1.21; 95% CI, 1.08–1.35 and AHR=1.55; 95% CI, 1.45–1.66, respectively), as well as for suicide (aHR=5.05; 95% CI, 2.46–10.37 and aHR=14.32; 95% CI, 7.44–27.55, respectively), when compared with matched controls. Data revealed a statistically significant (P <.0001) difference in mortality between the MDD before T2DM and MDD after T2DM groups, but a nonsignificant difference between the two regarding death by suicide.

“In conclusion, the study findings indicated suicide and mortality rates were higher in both the MDD before and MDD after T2DM groups when compared with matched controls,” Huang and colleagues wrote. “Public health initiatives are needed to survey and treat comorbid MDD and T2DM.”