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

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.