Association between ADHD symptoms, physical effort discounting, and unhealthy lifestyles in adults.

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental condition marked by difficulties with attention, increased activity levels, and impulsive behaviour, which can impact social, academic, and work-related performance. Its presence in adults is often overlooked and inadequately addressed. Emerging research suggests a link between ADHD and unhealthy lifestyles, including sedentary behaviour, substance use, and effort discounting, a decision-making process where individuals undervalue rewards requiring significant physical or cognitive effort. This study investigates the association between ADHD symptoms, physical effort discounting, and indicators of unhealthy lifestyles in young adults. We recruited 181 participants aged 18-33 years. They completed the Effort-Expenditure for Rewards Task (EEfRT) and a hypothetical effort-discounting task, alongside questionnaires assessing ADHD and developmental co-ordination disorder (DCD) symptoms, physical activity, alcohol, tobacco and drug use. A logistic mixed model was used to analyze effort-discounting decisions, while regression analyses assessed the influence of ADHD symptoms and effort discounting on unhealthy lifestyle indicators. EEfRT decisions were significantly influenced by reward probability, monetary value, and ADHD medication status, whereas choices in the hypothetical effort-discounting task were influenced by money, effort and ADHD symptoms. When exploring the association between all variables, ADHD symptoms were positively correlated with effort discounting in the hypothetical task, smoking, and DCD. Effort discounting was associated with a sedentary lifestyle while smoking correlated with higher BMI and alcohol consumption. Linear and logistic regressions suggested that ADHD symptoms and effort discounting were associated with a sedentary lifestyle, and smoking status was significantly explained by ADHD symptoms. These findings highlight the need for targeted interventions addressing both ADHD symptomatology and lifestyle factors to improve outcomes in affected individuals.