Why Psychotherapy Matters for Bipolar II Disorder

A less studied but common phenotype, bipolar II disorder (BP II) affects over 1% of the population and is associated with significant morbidity and psychosocial impairment. Despite its clinical importance, relatively little is known about treatments for BP II. Very few studies have systematically evaluated the efficacy of pharmacotherapy for BP II and even fewer have examined the role of psychotherapy in its management. Psychiatrists often prescribe medications that have been tested for bipolar I disorder (BP I) for their patients with BP II—even though the evidence does not support this practice. In contrast, psychotherapies developed for BP I are not widely used for BP II, even though psychotherapy has few known side effects and directly targets the psychosocial impairment and functional deficits associated with bipolar disorder.

My colleagues and I conducted a study designed to compare psychotherapy plus pill placebo to psychotherapy plus quetiapine as treatments for major depressive episodes occurring in the context of BP II. The study was novel in that it was the first to systematically test psychotherapy as monotherapy (without adjunctive medication) as a treatment for BP II depression. In our trial, both groups improved significantly over the 20-week treatment period, although those who received psychotherapy plus quetiapine did somewhat better than those who received psychotherapy plus pill placebo. The incremental advantage associated with receipt of pharmacotherapy, however, was associated with a cost. Those who received psychotherapy plus quetiapine experienced a relative increase in their BMI and more side effects. We were particularly interested to learn that those who got the treatment they preferred were 4 times as likely to respond to it as those who got a treatment they did not want. We concluded that if individuals with BP II prefer psychotherapy alone—perhaps because they do not wish to incur the negative consequences associated with pharmacotherapy—they have a high probability of doing well. When selecting a treatment for BP II depression, risks for harm and patient preferences matter.

Our study tested Interpersonal and Social Rhythm Therapy (IPSRT), an evidence-based psychotherapy that was originally developed for BP I and adapted for BP II. IPSRT focuses on helping individuals develop more regular routines and rhythms to address underlying disturbances in circadian rhythms. It also helps patients address interpersonal problems that are associated with the onset of a mood episode. Our research shows that use of this bipolar-specific psychotherapy provides individuals with tools needed to regulate their routines and relationships, resulting in significant improvement in mood and global functioning. Unlike medications, IPSRT provides skills that have potentially enduring effects beyond the end of treatment and have no known side effects. Although access to trained psychotherapists remains a concern, it may be reasonable to consider a stepped care model for management of BP II depression by offering a trial of IPSRT to those who wish it, followed by the addition of medication for those who need it. This approach may minimize the risk of metabolic consequences of medications that have not been well-tested for BP II while providing patients with useful tools that help them address psychosocial determinants of an episode.

Financial disclosure:Dr Swartz has been a consultant for Myriad Genetics and Otsuka and has received grant/research support from Myriad Genetics, royalties from UpToDate, and an editorial stipend from American Psychiatric Association Publishing.