The effect of personalized guideline-concordant treatment on quality of life and functional impairment in bipolar disorder

Conclusions Optimized care for bipolar disorder improves overall quality of life and life functioning, with no additional benefit from adjunct moderate doses of lithium. Illness burden and psychosocial stressors were associated with worse quality of life and lower functioning in individuals with bipolar disorder.

Objectives The aims of this study were to evaluate correlates and predictors of life functioning and quality of life in bipolar disorder during a comparative effectiveness trial of moderate doses of lithium.

Methods In the Lithium treatment moderate-dose use study (LiTMUS), 283 symptomatic outpatients with bipolar disorder type I or II were randomized to receive lithium plus "optimal personalized treatment (OPT)", or OPT alone. Participants were assessed using structured diagnostic interviews, clinician-rated blinded assessments, and questionnaires. We employ linear mixed effects models to test the effect of treatment overall and adjunct lithium specifically on quality of life or functioning. Similar models are used to examine the association of baseline demographics and clinical features with quality of life and life functioning.

Results Quality of life and impaired functioning at baseline were associated with lower income, higher depressive severity, and more psychiatric comorbid conditions. Over 6 months, patients in both treatment groups improved in quality of life and life functioning (p-Values<0.0001); without a statistically significant difference between the two treatment groups (p-Values>0.05). Within the lithium group, improvement in quality of life and functioning was not associated with concurrent lithium levels at week 12 or week 24 (p-Values>0.05). Lower baseline depressive severity and younger age of onset predicted less improvement in functioning over 6 months.