Irritability signals suicidal ideation in major depression

Among patients with major depressive disorder (MDD), high levels of irritability are linked to suicidal behaviour, a study suggests.

The study used data from three trials: Combining Medications to Enhance Depression Outcomes (CO-MED, n=665), Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care (EMBARC, n=296), and Suicide Assessment Methodology Study (SAMS, n=266).

Clinical and demographic characteristics were similar across the cohorts, with the exception of the proportion of unemployed participants, which was higher in CO-MED (50.2 percent) than in SAMS (35.8 percent). Furthermore, participants in SAMS reported lower levels of suicidality (assessed using three-item suicidal thoughts factor of Concise Health Risk Tracking scale) than in CO-MED or in EMBARC.

Repeated-measures mixed model analyses revealed an association between higher irritability (measured using five-item irritability domain of Concise Associated Symptom Tracking scale) and higher suicidal ideation (SI) concurrently (estimates, 0.18 in CO-MED, 0.64 in EMBARC, and 0.26 in SAMS; p<0.0001, p<0.0001, and p<0.0001, respectively).

At week 2, greater reductions in irritability from baseline predicted lower levels of subsequent SI (estimates, −0.08 in CO-MED, −0.50 in EMBARC, and −0.12 in SAMS; p=0.023, p<0.0001, and p=0.024, respectively). The estimates persisted despite controlling for anxiety or insomnia.