Clinical, sociodemographic and environmental predicting factors for relapse in bipolar disorder: A systematic review

Bipolar disorder (BD) is a chronic and recurrent illness characterized by manic, mixed or depressive episodes, alternated with periods of euthymia. Several prognostic factors are associated with higher rates of relapse, which is crucial for the identification of high-risk individuals. This study aimed at systematically reviewing the existing literature regarding the impact of sociodemographic, clinical and environmental factors, in clinical relapses, recurrences and hospitalizations due to mood episodes in BD. A systematic search of electronic databases (PubMed, Cochrane library and Web of Science) was conducted to integrate current evidence about the impact of specific risk factors in these outcomes. Fifty-eight articles met the inclusion criteria. Studies were grouped by the type of factors assessed. Family and personal psychiatric history, more severe previous episodes, earlier age of onset, and history of rapid cycling are associated with clinical relapses, along with lower global functioning and cognitive impairments. Unemployment, low educational status, poorer social adjustment and life events are also associated with higher frequency of episodes, and cannabis with a higher likelihood for rehospitalization. Small sample sizes, absence of randomized clinical trials, diverse follow-up periods, lack of control for some confounding factors, heterogeneous study designs and diverse clinical outcomes. Although current evidence remains controversial, several factors have been associated with an impaired prognosis, which might allow clinicians to identify patients at higher risk for adverse clinical outcomes and find modifiable factors. Further research is needed to elucidate the impact of each risk factor in the mentioned outcomes.