Gender Differences in 2 Clinical Trials of Adults With Attention-Deficit/Hyperactivity Disorder: A Retrospective Data Analysis

Introduction: Studies show that, in childhood attention-deficit/hyperactivity disorder (ADHD), boys have the combined type with externalizing behaviors more frequently, and girls have the inattentive type with increased internalizing disorders more frequently.

Method: This study explored gender differences in adults with ADHD in 2 large, placebo-controlled, multicenter studies conducted from 2000 to 2001. Information collected included 2 measures of ADHD, multiple psychological measures, general physical symptoms, and treatment response.

Results: Thirty-four percent of the subjects were female. Women were rated as more impaired on every measure of ADHD symptoms including total Conners’ Adult ADHD Rating Scale-Investigator Format (CAARS-INV), total Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS), and most subscales of both measures. More women (75%) had combined type compared with men (62%). Women showed a more complex presentation, with higher scores on the Hamilton Rating Scale for Anxiety (HAM-A) and the Hamilton Rating Scale for Depression, 17-item version (HAM-D₁₇), more sleep problems, and more past DSM-IV Axis I diagnoses. Both sexes displayed substantial impairment on 3 Psychological General Well-Being Schedule factors: tension-anxiety, life satisfaction, and vitality-drive. Women experienced significantly (p = .003) greater rates of emotional dysregulation (37%) versus men (29%) as defined by a cluster of symptoms on the WRAADDS. The emotional dysregulation factor is derived by combining 3 symptoms–temper control, mood lability, and emotional overreactivity–from the Utah Criteria for ADHD in adults. These symptoms are considered associated symptoms in the DSM-IV description of ADHD. Women also experienced greater improvement (p = .011) on this symptom factor.

Conclusion: In contrast to the results from childhood studies, women were more impaired than men on ADHD scales in our study. The higher level of emotional symptoms and more complicated presentation in women may obscure the diagnosis of ADHD. Thus, the assessments of adults with ADHD should include an exploration of the emotional dimensions of the illness.