A brief assessment of psychosocial functioning of subjects with bipolar I disorder

Those afflicted with bipolar disorder often suffer from substantial functio nal impairment both when in episode and when in remission. This study exami ned the psychometric properties of a brief assessment of psychosocial funct ioning, the Range of Impaired Functioning Tool (LIFE-RIFT), among subjects with bipolar I disorder. The study sample consisted of 163 subjects who pre sented with bipolar I disorder at intake into the NIMH Collaborative Depres sion Study (CDS). All LIFE-RIFT items come from the Longitudinal Interval F ollow-up Evaluation (LIFE). Follow-up data that were used to examine the re liability and validity of the scale come from assessments of psychosocial f unctioning that were conducted 6, 12, 18, and 24 months after intake into t he CDS. The results of factor analyses indicate that the scale items are me asures of one construct, psychosocial functioning. The interrater agreement on the scale score was very good with an intraclass correlation coefficien t was 0.94. The internal consistency reliability among the scale items was uniformly satisfactory over the four assessment periods, with coefficient a lpha ranging from 0.78 to 0.84. Mixed-effect regression analyses showed tha t during mood episodes subjects were significantly more impaired than those in recovery. In conclusion, the psychometric properties of the LIFE-RIFT w ere examined in subjects with bipolar I disorder. The analyses from this lo ngitudinal, observational study provide empirical support for the reliabili ty and validity of the scale. The LIFE-RIFT provides a brief, inexpensive a lternative to scales currently used to assess psychosocial functioning and can be easily added to semistructured assessments that are used in clinical and treatment outcome studies.