Associations between health risk behaviors and symptoms of schizophrenia and bipolar disorder: a systematic review

Objective: To systematically review the literature to determine if health risk behaviors in patients with schizophrenia or bipolar disorder are associated with subsequent symptom burden or level of functioning. Method: Using the PRISMA systematic review method we searched PubMed, Cochrane, PsychInfo and EMBASE databases with key words: health risk behaviors, diet, obesity, overweight, BMI, smoking, tobacco use, cigarette use, sedentary lifestyle, sedentary behaviors, physical inactivity, activity level, fitness, sitting AND schizophrenia, bipolar disorder, bipolar illness, schizoaffective disorder, severe and persistent mental illness, and psychotic to identify prospective, controlled studies of greater than 6 months duration. Included studies examined associations between sedentary lifestyle, smoking, obesity, physical inactivity and subsequent symptom severity or functional impairment in patients with schizophrenia or bipolar disorder. Results: Eight of the 2130 articles identified met inclusion criteria and included 508 patients with a health risk behavior and 825 controls. Six studies examined tobacco use, and two studies examined weight gain/obesity. Seven studies found that patients with schizophrenia or bipolar illness and at least one health risk behavior had more severe subsequent psychiatric symptoms and/or decreased level of functioning. Conclusion: Tobacco use and weight gain/obesity may be associated with increased severity of symptoms of schizophrenia and bipolar disorder or decreased level of functioning. (C) 2013 Elsevier Inc. All rights reserved.