**Background:** Adult attention-deficit/hyperactivity disorder (ADHD) is associated with risky decision-making behavior, but laboratory studies often fail to capture daily-life deficits. According to the Dual Pathway Model, two pathways guide behavior: cognitive-analytic (cold functions) and intuitive-affective (hot functions). Over the lifespan, cognitive impairments in ADHD may improve while affective dysfunctions worsen. The authors hypothesized that risky decision-making in adult ADHD arises predominantly from deficits in affective (hot) processes, and that altered physiological responses (skin conductance) would be observed during risky decision-making.
**Methods:** Twenty-eight adults with ADHD (DSM-V criteria, recruited from the University Hospital Bonn) and 28 healthy controls (HC) participated. Inclusion criteria: age 18–60, fluent German, no neurological diseases, no depressive disorder, no borderline personality disorder, no psychosis. ADHD participants ceased medication 24 hours prior. Groups did not differ significantly in age, gender, verbal IQ, or education. Participants completed clinical questionnaires (CAARS, WURS-k, BDI-II, BSL-95) and self-report measures of risk behavior (DOSPERT) and emotional competence (EKF). Skin conductance was recorded at 5,000 Hz using a Biopac MP150 system with Ag-AgCl electrodes on the non-dominant hand. Participants performed a modified Balloon Analogue Risk Task (BART) with 60 trials (30 high reward, 30 low reward). Anticipatory SCR (aSCR) was measured 1–6 seconds after stimulus onset; reactive SCR (rSCR) was measured 1–3 seconds after feedback. Linear mixed-effects models with random intercepts for participants and trials were used, with group and reward condition as fixed effects.
**Key Results:** Model 1 (aSCR) showed a significant main effect of group (β = −0.12, SE = 0.05, t = −2.63, p < 0.001), with higher aSCR in ADHD than HC (mean difference ADHD–HC = 0.09, SE = 0.03, t = 2.79, p = 0.005). Model 2 (RT) showed significant main effects of group (β = 219.51, SE = 39.88, t = 5.5, p < 0.001) and reward condition (β = 215.36, SE = 38.36, t = 5.61, p < 0.001), with HC showing longer RTs (mean difference ADHD–HC = −222, SE = 29.3, t = −7.59, p < 0.001) and both groups showing longer RTs under high reward (mean difference low–high = −218, SE = 27.2, t = −8.02, p < 0.001). Model 3 (RT predicted by aSCR) revealed a significant interaction of group and aSCR (β = 107.17, SE = 41.91, t = 2.56, p = 0.011): aSCR and RT were positively correlated in HC but negatively correlated in ADHD. Model 4 (rSCR) showed significant main effects of group (β = −0.14, SE = 0.05, t = −2.66, p = 0.008) and feedback (β = −0.11, SE = 0.05, t = −2.32, p = 0.02), with higher rSCR in ADHD (mean difference ADHD–HC = 0.098, SE = 0.04, t = 2.7, p = 0.007) and after loss (mean difference loss–gain = 0.07, SE = 0.03, t = 2.03, p = 0.042). Self-report: DOSPERT showed no group difference [F(1,54) = 0.285, p = 0.6, η² = 0.005]; EKF showed significantly lower emotional competence in ADHD [F(1,54) = 23.1, p < 0.001, partial η² = 0.3].
**Clinical Implications:** This is the first study to investigate hot functions as underlying mechanisms for risky decision-making in adult ADHD using SCR. Adults with ADHD exhibited heightened physiological arousal before decisions and after feedback, but this arousal did not translate into adaptive behavioral adjustments—unlike healthy controls, where higher anticipatory arousal was associated with longer (safer) reaction times. The negative correlation between aSCR and RT in ADHD suggests a disconnect between bodily signals and behavioral regulation. Self-report data confirmed impaired emotional competence in ADHD, while conscious risk perception was not different from controls, supporting the idea that deficits operate at an unconscious, affective level. The authors note limitations including potential medication effects, environmental noise on SCR recordings, limited comparability with child studies, and possible effects of unassessed comorbidities (e.g., antisocial personality disorder). They recommend future research on demographic effects (age, gender, education) and emphasize the importance of incorporating emotional therapeutic techniques in ADHD treatment.