Stability and change in attention problems across development: The emerging role of impulsivity in adulthood in a...

Attention problems (AP) remain relatively stable across childhood and adolescence, but shift in adulthood, with declining hyperactivity but persisting impulsivity. This pattern suggests that adult AP reflect both continuity of earlier symptoms and changes in their underlying expression. We used longitudinal twin data (N = 944, 474 females, 470 males; 91.9% White) to examine continuity of AP from childhood (ages 7-14) and adolescence (age 17) to adulthood (age 29), and whether impulsivity in adolescence (age 16) and adulthood (age 29) explains unique variance in adult AP beyond earlier AP. Childhood and adolescent AP significantly correlated with adult AP (rs = .15-.31), indicating moderate developmental continuity; however, adult impulsivity uniquely predicted adult AP (β = 0.43) beyond earlier AP and adolescent impulsivity. Twin models suggested that adult AP reflected both continuity of earlier genetic influences and novel genetic influences (r_A = 0.29-0.62), whereas nonshared environmental influences showed minimal continuity across time (r_E = -0.06-0.08). The partial association between adult impulsivity and adult AP, controlling for earlier measures, was primarily driven by nonshared environmental influences (89.1%) in adulthood, with smaller genetic overlap (10.9%). These findings indicate that adult AP reflect both stable developmental liability and adult-specific influences, and identify impulsivity as an important component of adult AP.