Subthreshold mixed states worsens bipolar outcomes
MedWire News: Bipolar patients with a current mood episode who have subthreshold symptoms of the opposite polarity have worse outcomes than those without such symptoms, Australian study findings suggest.
Mixed clinical states in bipolar disorder are diagnostically complex and have treatment implications. While the current criteria specify that mixed states require the presence of full symptoms for both depressive and manic episodes, the impact of subthreshold symptoms of opposite polarity has not been fully examined.
To investigate further, S Dodd, from the University of Melbourne in Victoria, and colleagues studied 239 patients with either bipolar I disorder or schizoaffective disorder, bipolar type, dividing them into either those having pure, mixed (≥3 concurrent hypomanic symptoms), or no depression (63, 33, and 143 patients, respectively) or pure, mixed (≥2 concurrent depressive symptoms), or no mania (3, 33, and 203 patients, respectively). Clinical data were collected every 3 months for 24 months.
At 24 months, mixed depression and pure depression groups had significantly worse outcomes on almost all measures than patients with no depression at study entry. Young Mania Rating Scale (YMRS) total scores were significantly higher in the mixed depression than pure depression groups. In addition, both manic and depressive symptomatologies were higher in mixed depression patients than other participants at every visit during follow-up.
Compared with other patients, those with mixed mania had significantly worse scores on the Short Form Health Survey Physical Component Score, 21-item Hamilton Depression Rating Scale total score, YMRS total score, Clinical Global Impressions Scale Mania, Depression, and Bipolar subscales, and Streamlined Longitudinal Interview Clinical Evaluation from the Longitudinal Interval Follow-up Evaluation total score.
Again, depressive and manic symptom scores were higher for mixed mania patients versus other participants at every visit, the team notes in the Journal of Affective Disorders.
“In participants with a current mood episode, the presence of subthreshold symptoms of the opposite polarity predicted an adverse prognosis,” the team says.
“Identification of three or more hypomanic symptoms in currently depressed participants or two or more depressive symptoms in currently manic participants was associated with poorer clinical outcomes over a 24-month period.”
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By Liam Davenport