Bipolar disorder (BD) is a complex and heterogeneous condition characterized by a variety of symptoms and marked variability in disease course. A patient with BD can experience episodes of depression, hypomania, mania, or psychosis and, indeed, can experience a mixture of emotional states or cycle rapidly between them. In fact, recent research has highlighted the prevalence of marked subsyndromal features between episodes,1 but despite currently available treatments, BD remains a chronic relapsing condition.2
Given the symptom profile of BD, it is not surprising that the diagnosis is typically associated with significant disability and impaired functioning. According to World Health Organization (WHO) estimates, BD was the 6th leading cause of disability worldwide among young adults at the turn of the century.3 For example, if BD develops in a woman at the age of 25, she may lose 9 years in life expectancy (because of cardiovascular and other medical problems), 14 years of productivity, and 12 years of good health.4 Disturbingly, the lifetime suicide rates of patients with BD (treated or not) may be as high as 15%.5
Beyond symptoms to quality of life
While outcomes in patients with BD have traditionally been assessed as objectively measured clinicalinformation (such as relapse rates, number of hospitalizations, or symptom reduction as rated by a clinician-rated scale), a number of arguments suggest the need for the addition of functional and quality-of-life (QOL) measures.6-8 It has been observed clinically, for example, that some patients appear to function poorly despite relatively few symptoms, while others function well in the context of relatively severe symptoms.7 Likewise, there is evidence for a disjunction between symptom change and QOL change in response to treatment, with the latter typically lagging substantially behind the former.9 Finally, as discussed later in this article, patients themselves attend to more than symptoms when assessing the success of their treatment, and it would be reasonable to expect that the treatment alliance would benefit when clinicians share this more holistic viewpoint.6
The movement toward a broader set of outcome measures in BD is consistent with a change in the zeitgeist of BD research in the past decade. Mirroring the developments that occurred in schizophrenia research a decade earlier,10 biopsychosocial models of BD have recently been proposed,11-13 and a number of adjunctive psychosocial treatments for BD have been found efficacious.14,15 Researchers from this contemporary tradition have called for expanded targets for therapy7 and, hence, an expanded range of outcome mea-surements in BD. Indeed, it may be in the area of functional outcomes that psychosocial interventions make their strongest contribution.16 As asserted by Harvey,17 for example: "recovery should not be defined merely by symptomatic remission or even syndromal remission; rather, recovery should include symptomatic recovery, syndromal recovery, functional recovery, and a return to an acceptable quality of life for the patient."
Although the terms "QOL" and "functioning" are often used interchangeably, it may be useful to distinguish between them. Functioning is typically clinician-assessed and refers to objective function in a variety of behavioral domains. In contrast, QOL is commonly understood as a subjective indicator of patient well-being. The WHO has described QOL as the "individuals' perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards, and concerns."18 Although the domains encompassed by QOL and functioning may overlap (eg, social, occupational, and independent living), the former are characterized by an emphasis on subjective assessment of satisfaction. This article focuses on the subjective assessments of QOL in BD. Given the limited evidence base, our review will not distinguish between a broad conceptualization of QOL and health-related quality of life (HRQOL), with the latter referring specifically to those aspects of life that are impacted by health or ill health.