Shared clinical associations between obesity and impulsivity in rapid cycling bipolar disorder: A systematic review

BACKGROUND: Obesity seems to show a two-way relationship with bipolar disorder (BD), representing not only a possible vulnerability factor but also a consequence of chronic mood dysregulation associated with an overall poor prognosis. Increased impulsivity has been described across all stages and phases of BD as being also associated with a worse prognosis. Although obesity and impulsivity are common features among rapid cycling bipolar disorder (RC-BD) patients, there is a lack of understanding about the clinical implications of these conditions combined in BD. METHODS: To explore and integrate available evidence on shared clinical associations between obesity and impulsivity in RC-BD a systematic search of the literature in the electronic database of the National Library of Medicine (PubMed) has been conducted. RESULTS: One hundred and fourteen articles were included in our systematic review. Among RC-BD patients, substance abuse disorders (SUDs), anxiety disorders (ADs), predominantly depressive polarity, chronic exposure to antidepressants, psychotic symptoms, suicidality, and comorbid medical conditions are strongly associated with both obesity and impulsivity. LIMITATIONS: Heterogeneity of published data, inconsistent measurements of both obesity and impulsivity in RC-BD and an absence of control for RC-BD in epidemiological surveys. Consequently, their combined impact on the severity of RC-BD is yet to be recognized and remains to be poorly understood. CONCLUSION: In RC-BD patients the co-occurrence of obesity and impulsivity is associated with an unfavorable course of illness, specific shared clinical correlates, negative psychosocial impact, and overall worse prognosis. There is a need to examine obesity and impulsivity as modulating factors and markers of severity in RC-BD.