Reuven Dar of Tel Aviv University's School of Psychological Sciences and Amitai Abramovitch, who completed his doctorate under Dar's supervision, said groups of both OCD and ADHD patients had difficulty controlling their abnormal impulses in a laboratory setting. However, only the ADHD group had significant problems with these impulses in the real world.
Dar said OCD and ADHD might appear similar on a behavioral level, but the mechanism behind the two disorders differed greatly.
People with ADHD are impulsive risk-takers, rarely reflecting on the consequences of their actions, while OCD are all too concerned with consequences, causing hesitancy, difficulty in decision-making and the tendency to over-control and over-plan, Dar said.
The findings, published in the Journal of Neuropsychology, provide more accurate guidelines for correct diagnosis.
Dar noted treatment plans for the two disorders can differ dramatically. Ritalin, a psychostimulant commonly prescribed to ADHD patients, can actually exacerbate OCD behaviors. The drug, if prescribed to an OCD patient, would only worsen symptoms, the study said.