Prevalence, correlates and comorbidity of irritability in adults with major depressive episode in the U.S. population (2012-2013)

Background: Irritability has been documented in major depressive episodes (MDE) in children and adolescents. However, the prevalence of irritability in MDE and its clinical correlates remain unknown in adults.

Method: We showed associations between the prevalence of irritability and its sociodemographic characteristics in a representative U.S. sample, along with the associations between irritability and other psychiatric disorders and its relationship with health-related quality of life. This cross-sectional study utilized a large national sample (n = 36,309) from the National Epidemiologic Survey on Alcohol and Related Conditions-III. Face-to-face interviews were conducted to collect sociodemographic characteristics, structured diagnoses, and self-reported irritability.

Results: The irritable MDE group (n = 4988) was compared to the non-irritable MDE group (n = 3065). The lifetime prevalence of irritability in MDE was estimated at 61.3%. Participants with irritable MDE were significantly more likely to report a lifetime history of psychiatric disorders (aOR = 1.96) than those with non-irritable MDE. Irritable MDE was also positively associated with severe MDE (aOR = 2.12). Participants with irritable MDE were more likely to report a lifetime history of suicide attempts (aOR = 1.15), substance use disorders (aOR = 1.54), mood disorders (aOR = 1.93), and anxiety disorders (aOR = 1.67). Participants with irritable MDE had lower levels of health-related quality of life than those with non-irritable MDE.

Conclusions: The majority of adults with MDE exhibits irritability. Irritability is associated with severe characteristics and comorbidities, leading to a higher burden of depression.

Significance: This study demonstrates a strong association between irritable MDE and psychiatric comorbidities, as well as a substantial burden of depression and related conditions. As a cross-sectional study using a representative sample of the U.S. population with highly reliable psychiatric diagnoses, our results are generalizable. Practitioners managing MDE should identify and treat these comorbidities.