Individuals prenatally exposed to tobacco smoke exhibited weaker response in some regions of the brain while processing a task that measures inhibition control (the ability to control inappropriate responses). Prenatal tobacco smoke exposure is a risk factor for adverse physical and mental outcomes in children. Growing evidence suggests that smoking during pregnancy may increase the risk of psychopathology such as attention-deficit/hyperactivity disorder (ADHD). Research on ADHD has suggested that individuals with the disorder may exhibit poor inhibitory control.