Quality of Life in Young Illicit Substance Abuser Men: Testing a Moderated Mediation Model of Age Related Decline in Executive Functions

Abstract

Background Earlier literature has documented age related decline in executive functions (EF) in normal aging adults, yet it is unclear whether age related EF decline is linked with quality of life (QoL) possibly mediating the link between age and QoL. Therefore, the study hypothesized that selective EF components would mediate the association between age and QoL domains in young substance abuser men and family history of substance use would moderate these mediated associations. Method A sample of 212 young substance abuser men (105 positive family history and 107 negative family history of substance use) performed on performance measures assessing selective EF components—inhibition and cognitive flexibility. Also, they reported their QoL on self-report measure of WHOQOL. Results Mean scores of the sample on all QoL domains were lower than expected by chance. Also, the participants with positive family history of substance use compared to those with negative family history scored significantly lower on all QoL domains except physical QoL. Mediation analyses revealed that of two EF components, only inhibition mediated the negative association of age with psychological, social, and environmental QoL. Furthermore, family history of substance use moderated all the significant mediations with stronger indirect negative associations in participants having a family history of substance use compared to those with no such history. Conclusion 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.