Interaction effect of contingency management and sex on delay-discounting changes among treatment-seeking smokers

Despite the potential influence of sex on delay-discounting rates, there is no previous evidence with regard to the effect of this variable on the clinical interventions aimed at modifying delay-discounting rates. This study assessed the effect of sex on the association between the type of treatment received (either cognitive-behavioral treatment [CBT] alone or combined with contingency management [CM + CBT]) and delay-discounting changes at end of treatment and 6-month follow-up. This aim was addressed after controlling for the influence of baseline delay discounting. Treatment-seeking smokers (N = 116) were randomly assigned to either CM + CBT (n = 69) or CBT alone (n = 47). Participants completed delay-discounting assessments at intake, at end of treatment, and at 6-month follow-up. Results showed that there was a significant interaction effect of treatment type and sex, such that women who received CM decreased their discounting more than women who did not. However, this effect was not found among men. Participants who discounted most at intake showed the greatest delay-discounting decreases. Lastly, smoking abstinence did not affect changes in delay discounting. The current results suggest that CM intervention may have a differential effect on delay-discounting changes as a function of sex. This finding supports the relevance of considering the effect of individual variables when assessing changes in delay discounting due to clinical interventions.