Factors associated with functional recovery in bipolar disorder patients

Psychosocial and occupational impairments in patients diagnosed with bipolar disorder (BPD) are highly prevalent despite modern therapeutic advances (1). A life-long and often debilitating illness, BPD affects at least 2% of the general population (2). As few as 20%–40% of BPD patients achieve social and occupational recovery to their own premorbid levels (1). In addition, only 19%–23% of adult BPD-I patients are married, compared to 60% of the general population (1). Of 2839 BPD patients in the Stanley Institute BPD Registry, 64% were unemployed even though 60% had some post-high school education or training, and 30% had completed college (3). Likewise, among the first 1000 BPD patients in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD), 82% had some college education compared to 52% in the general US population, but 37% were unemployed or disabled compared to 3.7% of the contemporaneous general population (4). Recovery among BPD patients has been conceptualized as involving several dimensions (5). Typically, syndromal recovery is defined as no longer meeting DSM criteria for an acute mood episode, symptomatic recovery as having low scores on standard ratings of mania and depression that indicate near-absence of symptoms, and functional recovery as regaining individual premorbid levels of psychosocial, residential, and occupational status (5). Using these criteria, the McLean-Harvard First Episode project followed first-episode, type I BPD patients from initial hospitalization for a DSM-IV manic or mixed episode: by two years, 98% achieved syndromal recovery, 72% symptomatic recovery, but only 43% reached functional recovery (6). With similar definitions, another study followed mid-course BP-I patients for a year after hospitalization for a manic or mixed episode: only 48% achieved syndromal recovery, 26% symptomatic, and 24% functional recovery (7). These studies suggest that nearly 60% of sometimes hospitalized, type I BPD patients treated by current methods failed to regain their own premorbid functional status within 1–2 years, even from illness-outset, and that prospects for functional recovery may be even poorer after prolonged illness. Moreover, symptomatic recovery does not necessarily lead directly to functional recovery. An important question is what factors might facilitate or impede functional recovery of BPD patients, particularly considering those in or near symptomatic recovery. Some studies found that higher socioeconomic status (based on years of education and highest level of employment in the previous year), older age at first manic episode, and shorter hospitalization for the first manic or mixed episode predicted functional recovery, as defined above, within 1–2 years (6,7). However, when functional outcome was assessed across 15 studies and for groups rather than on a within-patient basis for occupational, residential, or social functioning, few demographic or clinical characteristics consistently predicted functional outcome (8). Not yet specifically assessed is a relationship between functional recovery and neurocognitive functioning, which can be significantly impaired even among euthymic BPD type I or II patients (9,10), and may influence functional outcomes (11,12). Regarding neurocognitive functioning, euthymic BPD patients showed medium-to-large effect sizes (ES) for impairments of attention and processing speed (ES = 0.60–0.79), episodic memory (ES = 0.43–0.81), and executive functioning (ES = 0.47–0.71) in a meta-analytic review of 39 studies comparing 948 euthymic BPD patients and 1128 normal controls matched for age, sex, education, and estimated premorbid IQ (13). Cognitive impairment has been associated with impaired psychosocial functioning, even after adjusting for residual mood symptoms and relevant demographic and clinical variables (11). However, these studies used various, often broad, ratings of functional status, such as the Global Assessment of Functioning (GAF) Scale (12,14), Social Adjustment Scale (15), Multidimensional Scale for Independent Functioning (16), and none considered functional recovery based on individual return to baseline status. Given this background, we evaluated associations of demographic, clinical, and neurocognitive factors with functional recovery, defined as regaining individual premorbid or previous highest level of residential and occupational status, among euthymic or only mildly depressed BPD patients. We included residually depressed patients since longitudinal studies suggest that BPD patients experience subsyndromal depression or dysthymia during the majority of follow-up time in morbid states, despite access to modern treatments (17–19). We hypothesized that functional recovery would be associated with superior neurocognitive functioning, younger age, or more educational, professional and social accomplishment, including being married.