Patients who have recovered from bipolar disorder — at least 8 weeks of euthymia — were more likely to experience recurrence of depression or a slower recovery from depression if they had higher levels of irritability, found new research.
Laura D. Yuen and her colleagues at Stanford University assessed 503 outpatients with bipolar I or bipolar II disorder for irritability and recurrence from 2000-2011. Among these, 21% were currently recovered and 30% were currently depressed. At baseline, they assessed the patients with the STEP-BD Affective Disorders Evaluation, and then prospectively with the Clinical Monitoring Form for up to two years of naturalistic treatment during monthly visits.
Nearly twice as many currently depressed patients, 69%, had irritability as did recovered patients (36%). Among recovered patients, 61% of those with irritability and 39% of those without had lifetime anxiety; for current anxiety, those numbers were 58% and 24%, respectively. Irritability was also associated with higher rates of alcohol and substance use disorder, bipolar II disorder, having at least one first-degree relative with a mood disorder, attempting suicide at any point, an earlier age of onset, at least 10 prior episodes, rapid cycling in the previous year, current sadness, anhedonia and euphoria.
Past psychosis, however, was inversely related to irritability: 32% of patients with irritability and 55% of patents without had a history of psychosis/psychiatric hospitalization. Depressive recurrence in recovered patients occurred faster in those with current irritability than without. Among those with irritability, risk of hastened depressive recurrence was 3.8 times greater in those with lifetime anxiety disorder and 2.6 times greater in those with prior year rapid cycling, though history of psychosis again attenuated the risk.
Among currently depressed patients, irritability was also more likely in those with lifetime anxiety disorder, bipolar II disorder, having at least one first degree relative with a mood disorder, having at least 10 episodes, current euphoria, current anxiety and an earlier onset age. Delayed depressive recovery also occurred more in depressed patients with current irritability.
“The relationships between current irritability and both depressive recurrence and depressive recovery are consistent with the possibility of a particularly strong connection between current irritability and longitudinal depressive burden,” the authors concluded.
“Our observation of associations between current irritability and hastened depressive recurrence as well as delayed depressive recovery suggests that irritability may be an important indicator of longitudinal depressive burden in BD,” they continued. “Given the worse outcomes associated with bipolar depression and irritability, further examination of these relationships is warranted to better understand their mechanisms and clinical implications.”
The participants were American and mostly white, female, educated and insured, which may limit generalizability to other populations both in and outside the U.S.
Yuen LD, Shah S, Do D, et al. Current irritability associated with hastened depressive recurrence and delayed depressive recovery in bipolar disorder. Int J Bipolar Disord. 2016;4:15.