Moderation Effects of Substance Use on Physical and Mental Well-Being in Adults.

Background: Each year about one in five adults experiences mental illness. Although the independent physical and mental health consequences of alcohol misuse and cigarette smoking are well documented, little is known on how substance use moderates the relationship between physical and mental well-being.

Aim: The purpose of this study was to examine whether substance use moderates the relationship between physical activity and mental health in adults.

Methods: This was a secondary analysis of data provided by the Behavioral Risk Factor Surveillance System (BRFSS).

Results: Participants (N = 450,016) were adults who completed the BRFSS in 2017. Those who did not drink alcohol had fewer mental health problems when they indicated greater amounts of time spent doing physical activities each week. Last, smokers' number of mental health problems decreased as they engaged in more physical activity, whereas nonsmokers' number of mental health problems increased as they engaged in more physical activity.

Conclusions: The relationship between physical activity and mental health outcomes is well established and cannot be overemphasized. Nonetheless, substance abuse can moderate this relationship and should be routinely screened for by health care providers regardless of treatment setting.