ADHD Traits and Decision-Making

<p><strong>Delay discounting describes a decision-making phenomenon where rewards lose value because they are delayed. Delay discounting tasks are often used to explore the relationship between impulsive choice and ADHD traits, and conclusions are often extended to all delay discounting contexts across all populations. However, most studies use hypothetical postponing and experiential waiting contexts to explore delay discounting in populations of ADHD children and adolescents. A stronger link has been found between ADHD and delay discounting in experiential waiting contexts. However, fewer studies have explored hypothetical waiting contexts, and none have explored experiential postponing contexts. Therefore, it is not clear whether cross-study differences reflect the effects of waiting or the effects of experienced rewards. That is, research comparing discounting behaviours across different tasks or studies, may actually be comparing behaviours under different decision-making contexts. Hypothetical tasks use hypothetical delays and rewards the individual imagines, for example: would you prefer $100 now or $200 in six months? Comparatively, experiential tasks use rewards and delay the individual experiences, for example: would you prefer 50 points now or 100 points in 15 seconds? Hypothetical and experiential tasks can both be used to explore decisions about waiting and postponing. Delay discounting is much steeper in waiting contexts, where participants must wait during the delay (losing access to other rewards) than in postponing contexts where they can engage in other activities during the delay. In Experiment 1, we explored the relationship between delay discounting and ADHD traits in hypothetical and experiential waiting and postponing in a sample of New Zealand students. We replicated the finding that delay discounting was steeper in waiting than in postponing contexts. There was no relationship between ADHD scores and any delay discounting measure, perhaps because our sample did not include sufficient participants with very high or low ADHD scores. Consequently, in Experiment 2, we explored these relationships with an ADHD group and a comparison group. Again, discounting rates were significantly steeper in both waiting conditions. The ADHD and comparison group did not differ significantly from the comparison group on any delay discounting task. ADHD traits specifically inattentive (IA) and hyperactive/impulsive (H/I) symptom subscales, were, however, positively correlated with delay discounting. This correlation was also stronger in the experiential task and for the longest second-long delay lengths.</strong></p><p>Our results suggest that ADHD adults are more choice-impulsive across discounting contexts, but only when using correlational analyses with ADHD symptoms rather than group comparison. Additionally, IA and H/I trait symptoms similarly correlate with discounting in waiting and postponing contexts, but there is weaker support for this relationship in hypothetical tasks. Consequently, both delay aversion and temporal myopia may be important contributors to steeper discounting in experiential and hypothetical contexts. Future studies should continue to explore this relationship across all discounting contexts, in ADHD adults and children, ensuring they capture the full range of ADHD symptoms and design discounting conditions well.</p>