Irritability and elation in a large bipolar youth sample: relative symptom severity and clinical outcomes over 4 years

Abstract

Objective: To assess whether relative severity of irritability symptoms versus elation symptoms in mania is stable and predicts subsequent illness course in youth with DSM-IV bipolar I or II disorder or operationally defined bipolar disorder not otherwise specified.

Method: Investigators used the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children to assess the most severe lifetime manic episode in bipolar youth aged 7-17 years who were recruited from 2000 to 2006 as part of the Course and Outcomes of Bipolar Youth prospective cohort study (N = 361), conducted at university-affiliated mental health clinics. Subjects with at least 4 years of follow-up (N = 309) were categorized as irritable-only (n = 30), elated-only (n = 42), or both irritable and elated (n = 237) at baseline. Stability of this categorization over follow-up was the primary outcome. The course of mood symptoms and episodes, risk of suicide attempt, and functioning over follow-up were also compared between baseline groups.

Results: Most subjects experienced both irritability and elation during follow-up, and agreement between baseline and follow-up group assignment did not exceed that expected by chance (κ = 0.03; 95% CI, -0.06 to 0.12). Elated-only subjects were most likely to report the absence of both irritability and elation symptoms at every follow-up assessment (35.7%, versus 26.7% of irritable-only subjects and 16.9% of those with both irritability and elation; P = .01). Baseline groups experienced mania or hypomania for a similar proportion of the follow-up period, but irritable-only subjects experienced depression for a greater proportion of the follow-up period than did subjects who were both irritable and elated (53.9% versus 39.7%, respectively; P = .01). The groups did not otherwise differ by course of mood episode duration, polarity, bipolar diagnostic type, suicide attempt risk, or functional impairment.

Conclusions: Most bipolar youth eventually experienced both irritability and elation irrespective of history. Irritable-only youth were at similar risk for mania but at greater risk for depression compared with elated-only youth and youth who had both irritability and elation symptoms.