Eighteen nonmedicated adults with attention-deficit hyperactivity disorder (ADHD) and 18 who did not have ADHD were evaluated in a full-day simulated workplace experience. It was hypothesized that adults with ADHD would evidence greater impairments on simulated tasks, off-task behavior, and self-reported ADHD symptoms than those without ADHD. Participants were compared on self-reported ADHD symptoms, objective observations, and performance on written tasks. Significant differences were noted in reading comprehension and math fluency as well as observer-rated and self-reported behavior, but not attention. The results of this study suggest that ADHD among adults is associated with significant deficits in performance of workplace tasks, internal experiences, and external observations of core symptoms of ADHD.

The familial relationship between dyscalculia and attention-deficit/hyperactivity disorder (ADHD) was assessed. We conducted a familial risk analysis using probands with and without ADHD of both genders and their first-degree relatives. Participants were assessed with structured diagnostic interviews and a cognitive test battery. We found elevated rates of ADHD in relatives of both ADHD proband groups, regardless of dyscalculia status, and elevated rates of dyscalculia in relatives of probands with dyscalculia, irrespective of ADHD status. There was no evidence for cosegregation or assortative mating. Our findings support the hypothesis that ADHD and dyscalculia are independently transmitted in families and are etiologically distinct. These results reinforce the current nosological approach to these disorders and underscore the need for separate identification and treatment strategies for children with both conditions.

Background: The few controlled studies of methylphenidate (MPH) in adults with attention deficit/hyperactivity disorder (ADHD) have reported equivocal results. A previous, pilot study by our group suggested that these results were dure to inadequate dosing.Method: We conducted a randomized, 6-week, placebo-controlled, parallel study of MPH in 146 adult patients with DSM-IV ADHD using standardized instruments for diagnosis, separate assessments of ADHD, depressive and anxiety symptoms, and a robust average oral daily doze of 1.1 mg/kg/day.Results: We found a marked therapeutic response for the MPH treatment of ADHD symptoms that exceeded the placebo response (76% vs. 19%). Treatment was safe and well tolerated. Response to MPH was independent of socioeconomic status, gender, and lifetime history of psychiatric comorbidity.Conclusions: These results confirm that robust doses of MPH are effective in the treatment of adult ADHD.