A Moderated Mediation Model of Age-Related Decline in Selective Executive Functions and Quality of Life in Men with Substance Use Disorder.

Objective: It is known from earlier literature that substance use is associated with diminished executive functioning and decreased quality of life (QoL). The study extended this knowledge by assessing whether selective executive function components would mediate the association between age and QoL domains in young men with substance use disorder and whether family history of substance use would moderate these mediated associations. Method: A sample of 212 young inpatient men with substance use disorder (105 positive family history and 107 negative family history of substance use disorder) was selected from drug units/wards of government sector hospitals. Results: The participants with positive family history compared to those with negative family history scored significantly lower on all QoL domains except physical QoL. Mediation analyses revealed that only inhibition but not flexibility mediated the negative association of age with psychological, social, and environmental QoL. Furthermore, family history of substance use moderated all the significant mediated associations with stronger indirect negative associations in participants having a family history of substance use disorder compared to those with no such history. Conclusions: It is concluded that inhibitory control, which is vulnerable to aging, substance use, and family history of substance use, is an important factor related to QoL in young substance abuser men.