Prevalence and clinical correlates of irritability in major depressive disorder: a preliminary report from the Sequenced Treatment Alternatives to Relieve Depression study.
BACKGROUND
Irritability is a common feature of major depressive disorder (MDD), though it is not included in the DSM-IV diagnostic criteria for adult MDD and is not assessed in most standard depression rating scales. Irritability with or without depression has been associated with risk for suicide, violence, and cardiovascular disease.


METHODS
The prevalence of significant levels of irritability was examined among the first 1456 outpatients with nonpsychotic MDD entering the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Sociodemographic and clinical features were compared for participants who did and did not report irritability at least 50% of the time during the week preceding study entry.


RESULTS
Of 1456 evaluable subjects, 582 (40%) reported irritability more than half the time. These individuals were more likely than nonirritable subjects to be female, to be younger, to be unemployed, and to report a history of at least 1 suicide attempt. Functional status and quality of life were also poorer in this group. Irritability was correlated with overall depressive severity, which accounted for nearly all of the clinical differences noted, with the exception of vascular disease, for which the association persisted after controlling for age, sex, and depressive severity.


CONCLUSIONS
Irritability is prevalent among depressed outpatients and associated with a greater likelihood of suicide attempts, poorer functional status, and greater prevalence of vascular disease. It is correlated with overall depression severity and thus may not represent a distinct depressive subtype per se. The impact of irritability on course and treatment outcome merits further study.
Perlis
Roy H
RH
Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. rperlis@partners.org
Fraguas
Renerio
R
Fava
Maurizio
M
Trivedi
Madhukar H
MH
Luther
James F
JF
Wisniewski
Stephen R
SR
Rush
A John
AJ
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000553:Ambulatory Care; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007508:Irritable Mood; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D013406:Suicide, Attempted / Q000523:psychology / Q000706:statistics & numerical data; D016896:Treatment Outcome