Suicide in late-life depression with and without comorbid anxiety disorders

Comorbid anxiety in depression increases the risk of suicidal ideation and behavior, although data on death by suicide are scarce. We compared characteristics of depressed elderly patients with and without anxiety disorders who died by suicide.

From a 16-year clinical survey of all suicides in the UK (n = 25,128), we identified 1909 cases aged ≥60 years with a primary diagnosis of depression and no comorbidity other than anxiety disorders. Clinical characteristics of cases with (n = 333, 17.4%) and without (n = 1576) comorbid anxiety disorders were compared by logistic regression adjusted for demographic differences.

Compared with cases without comorbid anxiety disorders, cases with comorbid anxiety disorders were more likely to have a duration of illness over 1 year (OR(1-5 years)  = 1.4 [95% CI: 1.0-1.9], p = 0.061; OR(≥5 years)  = 1.4 [95% CI: 1.6-2.8], p < 0.001), were more frequently prescribed psychotropic drugs other than antidepressants, lithium, and antipsychotics (OR = 2.1 [95% CI: 1.6-2.7], p < 0.001) and were more distressed during their last contact with services (OR = 1.3 [95% CI: 1.0-1.7], p = 0.037). In contrast, clinicians estimated the immediate and long-term suicidal risks lower in those with comorbid anxiety disorders (OR = 0.6 [95% CI: 0.3-0.9], p = 0.011 and OR = 0.7 [95% CI: 0.6-1.0], p = 0.028, respectively).

Among depressed suicide cases, a comorbid anxiety disorder was identified in one out of six cases and associated with a higher prevalence of several suicide risk factors. This is important, as the detection of anxiety disorders comorbid to depression seems rather low and even when recognized clinicians rated such individuals as at low suicide risk.