Quality of life and clinical outcomes in bipolar disorder: An 8-year longitudinal study

•Quality of Life (QoL) is negatively affected by depressive episodes and is rather stable throughout the course of patients diagnosed with Bipolar Disorder (BD).•Higher QoL scores, both at baseline and throughout the course of illness, may be associated to a higher occurrence of manic episodes, while lower QoL scores may be predictive of a higher occurrence of depressive episodes.•OCD, PTSD and Substance Abuse comorbidities may be an important predictor of QoL in BD patients. This longitudinal study examined the relationship of Quality of Life (QOL) throughout an 8-year follow-up period with baseline and longitudinal clinical variables indicative of outcome in patients with Bipolar Disorder (BD). 36 participants, ages 18–70, were recruited from the Bipolar Disorder Research Program (PROMAN) outpatient clinic. Participants completed the WHOQOL-BREF questionnaire in 2009 (baseline), 2015 (6-years) and 2017 (8-years), with high scores being associated with better quality of life. Baseline clinical variables were collected through the Structured Clinical Interview for DSM-IV (SCID-IV) and a structured baseline interview for demographic and clinical assessment. Longitudinal clinical variables were collected through medical records, including mood charts and mood symptoms scales. The results suggest that the QoL, as measured by the WHOQOL-BREF scale, is negatively affected by depressive episodes and is rather stable throughout the course of patients diagnosed with BD. In our study, all three scores were negatively correlated to depressive episodes, and one WHOQOL-BREF score was positively correlated to manic episodes, suggesting that higher scores, both at baseline and throughout the course of the disorder, may be associated to a higher occurrence of manic episodes, while lower QoL scores may be predictive of a higher occurrence of depressive episodes. Also, all three scores revealed significant positive correlations between themselves, suggesting QoL, as measured by the WHOQOL-BREF, remained constant throughout the 8-year observed period. Finally, patients presenting Obsessive Compulsive Disorder (OCD), Post-Traumatic Stress Disorder (PTSD) and substance abuse comorbidities revealed consistent lower WHOQOL-BREF scores, suggesting that these comorbidities may be an important predictor of QoL in BD patients.