Clustering of social disadvantage with attention-deficit/hyperactivity disorder in young adults: A register-based study in Sweden.

The clustering of social disadvantage with attention-deficit/hyperactivity disorder (ADHD) in young adulthood is not well understood. We examined the clustering of ADHD with low educational attainment and unemployment in young adulthood; whether such clustering is stronger when unemployment is prolonged; and whether further clustering of disability pensioning, low education and unemployment occurs among those with ADHD. Data were obtained from Swedish health, demographic and social security registers from which 8,990 individuals with recorded ADHD diagnoses at the age of 10-35 and their 44,387 matched referents without mental disorders. Social disadvantage was measured using data on educational attainment, unemployment and disability pension from the diagnosis year or age 19 if diagnosed at younger age. Clustering was examined by comparing observed and expected occurrence (O/E ratio) of all possible combinations of ADHD, low education and unemployment, and, among those with ADHD, additional combinations with new-onset disability pension. The likelihood of having neither ADHD, low education nor unemployment was increased (O/E ratio = 1.20, 95% confidence interval 1.19-1.20 at baseline; 1.18, 1.17-1.18 at follow-up), as well as having all three characteristics (O/E ratio = 3.99, 3.89-4.10 at baseline; 5.68, 5.47-5.89 at follow-up). This clustering was stronger among women than men and when unemployment was prolonged. The results suggest that low education and unemployment appear to cluster remarkably with ADHD among young adults, more so among women and when unemployment is prolonged.