Attention-Deficit/Hyperactivity Disorder and Monetary Delay Discounting: A Meta-Analysis of Case-Control Studies

Abstract

Background A growing number of studies have investigated delay discounting, a behavioral economic index of impulsivity, and its relevance to attention deficit hyperactivity disorder (ADHD), but with mixed findings. The current meta-analysis synthesizes the literature on the relationship between monetary delay discounting and ADHD in studies using case-control designs. Specifically, the objectives were: 1) to characterize the aggregated differences in monetary delay discounting between individuals with ADHD (cases) and controls in studies using categorical case-control designs; 2) to examine potential differences based on sample age (<18 vs. >18), reward outcome (real vs. hypothetical), and prevalence of conduct disorder and oppositional defiant disorder in the sample; and 3) to evaluate potential small-study (publication) bias in the literature. Methods From 567 candidate articles, 21 independent investigations yielded 25 case-control comparisons (total N=3,913). Random effects meta-analysis was conducted using Cohen's d as the common effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger tests, and metaregression of publication year and effect size. Results Across studies, a statistically significant difference of medium magnitude effect size was present for the case-control comparisons (d=0.43; p < 10−15). No significant differences based on sample age, reward outcome, or comorbid status was detected. Minimal heterogeneity and evidence of publication bias was present. Conclusions These findings provide robust evidence that delay discounting is significantly elevated among individuals with ADHD compared to controls. Gaps in the literature and the importance of characterizing the neural and genetic bases of this relationship are discussed.

The decision neuroscience perspective on suicidal behavior

“…The notion of subjective value is central to understanding how our brain converts disparate inputs, such as delay and magnitude of rewards, into a single currency, enabling us to choose among alternative options. The degree to which humans discount the value of delayed outcomes differs across people, with high discount rates (lower willingness to delay gratification) associated with trait impulsivity, addiction and attention deficit-hyperactivity disorder [33,34]. Does this association extend to suicide?…”

Neuroanatomical foundations of delayed reward discounting decision making

“…Steep discounting of future rewards is considered a form of impulsivity and has been associated with a variety of different behaviors in normative samples, such as credit card debt (Meier and Sprenger, 2010) and completing regular health screenings (Bradford, 2010). Furthermore, precipitous DRD has been consistently associated with psychiatric disorders such as substance use disorders, gambling disorder, and attention deficit hyperactivity disorder (Amlung et al, 2016b; Jackson and MacKillop, 2016; MacKillop et al, 2011; Reynolds, 2006). …”

Genome-wide association study of delay discounting in 23,217 adult research participants of European ancestry

“…--Delay discounting (DD) is a fundamental component of impulse control 1 and is exaggerated in patients with diseases including attention-deficit/hyperactivity disorder (ADHD) 3 , substance use disorders 4 and obesity 5 . DD is included in the National Institute of Mental Health (NIMH)'s Research Domain Criteria (RDoC) initiative 6 , which focuses on psychiatric disorders as extremes of normal tendencies, based on a biological understanding of behavior.…”