Treatment adherence in bipolar I and schizoaffective disorder, bipolar type

Background: Poor adherence rates in Bipolar Disorder type I (BDI) and Schizoaffective Disorder, bipolar type (SAD) may be high This study was aimed at comparing the clinical correlates of adherence to treatment and the course of illness in BDI and SAD patients.

Methods: 75 SAD and 150 BDI DSM-IV outpatients were included. Adherence was assessed on the basis of patients' and care-givers' reports and serum levels, when available. Socio-demographic, clinical and treatment variables were collected and compared between diagnostic subsamples and then between goodly and poorly adherent patients. Multiple logistic regressions were performed, controlling for diagnostic subsample differences, to identify correlates of adherence in BDI and SAD groups.

Results: Poor adherence was highly prevalent both in BDI (32%) and in SAD patients (44%), with no significant differences between diagnostic categories. Presence of psychotic symptoms (p=0.029), higher number of manic relapses (p<0.001), comorbidity with personality disorders (p=0.002), and lithium therapy (p=0.003) were associated with poor adherence to treatment. Diagnostic subgroup analyses showed different predictive models, with the BDI poorly adherent subsample being more likely to include comorbid personality and manic recurrences and the SAD poorly adherent subsample being less clinically predictable.

Limitations: The cross-sectional nature of the study limits de capacity to ascertain the direction of the relationship between certain variables.

Conclusions: Rates of poor adherence to oral treatments are similar in SAD and BDI. BDI patients with comorbid personality and substance use disorders are likely to be poorly adherent. Treatment adherence may be more difficult to predict in SAD patients.