BACKGROUND: Although irritability is a core symptom of DSM-IV major depressive disorder (MDD) for youth but not adults, clinical studies find comparable rates of irritability between nonbipolar depressed adults and youth. Including irritability as a core symptom of adult MDD would allow detection of depression-equivalent syndromes with primary irritability hypothesized to be more common among males than females. We carried out a preliminary examination of this issue using cross-national community-based survey data from 21 countries in the World Mental Health (WMH) Surveys (n = 110,729). METHODS: The assessment of MDD in the WHO Composite International Diagnostic Interview includes one question about persistent irritability. We examined two expansions of the definition of MDD involving this question: (1) cases with dysphoria and/or anhedonia and exactly four of nine Criterion A symptoms plus irritability; and (2) cases with two or more weeks of irritability plus four or more other Criterion A MDD symptoms in the absence of dysphoria or anhedonia. RESULTS: Adding irritability as a tenth Criterion A symptom increased lifetime prevalence by 0.4% (from 11.2 to 11.6%). Adding episodes of persistent irritability increased prevalence by an additional 0.2%. Proportional prevalence increases were significantly higher, but nonetheless small, among males compared to females. Rates of severe role impairment were significantly lower among respondents with this irritable depression who did not meet conventional DSM-IV criteria than those with DSM-IV MDD. CONCLUSION: Although limited by the superficial assessment in this single question on irritability, results do not support expanding adult MDD criteria to include irritable mood.

The World Health Organization World Mental Health (WMH) Survey Initiative was supported by the National Institute of Mental Health (NIMH; R01 MH070884), the John D. and Catherine T. MacArthur Foundation, the Pfizer Foundation, the US Public Health Service (R13-MH066849, R01-MH069864, and R01 DA016558), the Fogarty International Center (FIRCA R03-TW006481).The São Paulo Megacity Mental Health Survey is supported by the State of São Paulo Research Foundation (FAPESP) Thematic Project Grant 03/00204–3. The ESEMeD project is funded by the European Commission (Contracts QLG5–1999-01042; SANCO 2004123), the Piedmont Region (Italy), Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Spain (FIS 00/0028), Ministerio de Ciencia y Tecnología, Spain (SAF 2000–158-CE), Departament de Salut, Generalitat de Catalunya, Spain, Instituto de Salud Carlos III (CIBER CB06/02/0046, RETICS RD06/0011 REM-TAP) . The World Mental Health Japan (WMHJ) Survey is supported by the Grant for Research on Psychiatric and Neurological Diseases and Mental Health (H13-SHOGAI-023, H14- TOKUBETSU-026, H16-KOKORO-013) from the Japan Ministry of Health, Labour and Welfare. The Lebanese National Mental Health Survey (LEBANON) is supported by the Lebanese Ministry of Public Health, the WHO (Lebanon), National Institute of Health/Fogarty International Center (R03 TW006481–01). The Mexican National Comorbidity Survey (MNCS) is supported by The National Institute of Psychiatry Ramon de la Fuente (INPRFMDIES 4280) and by the National Council on Science and Technology (CONACyT-G30544-H). The South Africa Stress and Health Study (SASH) is supported by the US National Institute of Mental Health (R01-MH059575). The Ukraine Comorbid Mental Disorders during Periods of Social Disruption (CMDPSD) study is funded by the US National Institute of Mental Health (RO1-MH61905). The US National Comorbidity Survey Replication (NCS-R) is supported by the National Institute of Mental Health (NIMH; U01-MH60220) with supplemental support from the Robert Wood Johnson Foundation (RWJF; Grant 044708)