Adult ADHD – The Challenges of Diagnosing and Treating

Gender differences in symptomatology to consider when diagnosing

Research in the last decade has also revealed that ADHD symptomatology differs according to gender. In childhood ADHD, boys have the combined type with more frequent externalizing behaviors, while girls have the inattentive type with more frequent internalizing disorders.8,9 In other words, boys can be more raucous and rebellious while girls tend to withdraw. These gender differences are also apparent in adult ADHD. Often, it is the symptoms of the adult female with ADHD that are more difficult to unmask because of their internalized nature. A retrospective data analysis in which 34% of the adults were female showed that women:10

    • Were rated as more symptomatic 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
    • Were more likely to have combined type ADHD (75% vs. 62%)
    • 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-D[17]), more sleep problems, and more past DSM-IV Axis I diagnoses
    • Experienced more emotional dysregulation – lack of temper control, mood lability, emotional overreactivity – than men (37% vs. 29%; P=0.003)

For these reasons, an assessment of adults – both women and men – should include an examination of the emotional extent of the illness.

Treatment of adult ADHD

Treatment for adult ADHD is becoming parallel with treatment for childhood ADHD as clinical studies are now both including and highlighting treatment efficacy in adults, with the FDA granting indications for use in adult patients. Currently, long-acting psychostimulants such as methylphenidate, mixed amphetamine salts, lisdexamfetamine as well as non-stimulants are used in the treatment of ADHD. Although psychostimulants have been shown to be effective and safe for the treatment of ADHD, approximately 30% of those who are prescribed stimulants for ADHD either do not respond to or do not tolerate these treatments.11

Non-adherence to medication due to the array of related side effects – insomnia, tics, mood swings, aggression12 – is a notable reason for treatment failure. While more studies have focused on ADHD medication adherence in children/adolescents than in adults, studies of pharmacy claims databases and treatment studies have revealed that the prevalence of medication discontinuation or non-adherence ranges from 13% to 64% when all age groups are considered.13