Adults with attention-deficit/hyperactivity disorder showed differences by sex and by presentation. Females had higher symptom severity, more depression and anxiety, and greater disability than males. Males reported higher use of alcohol, tobacco, and cannabis. The combined presentation had greater clinical severity, higher depression and anxiety scores, higher impulsivity, more substance use, and higher disability than the inattentive presentation. Sleep quality did not differ by sex or presentation. Psychosocial functioning did not differ between presentations. Only disability showed a sex-presentation interaction, with females in the combined presentation having the highest impairment.
Females received diagnoses at a substantially later age than males: 29 years vs 24 years—a nearly 5-year delay. Presentation distribution and age at symptom onset did not differ by sex.
Attention-deficit/hyperactivity disorder (ADHD) has a pooled prevalence of 3% in adults. Approximately 80% of adult patients with ADHD have a comorbid mental health disorder.
Specific substance use prevalence rates showed clear sex differences: alcohol use was reported by 39% of males vs 28% of females; tobacco use by 33% of males vs 27% of females; and cannabis use by 23% of males vs 13% of females.
Patients with the inattentive presentation were more often working or studying (83%) compared with those with the combined presentation (78%). Legal problems were substantially more frequent in the combined presentation, affecting 18% vs 9% of those with the inattentive presentation.
The study included 900 adults (55% male, mean age 37 years), with the combined presentation present in 48% of participants. Patients were evaluated in a university hospital adult ADHD program through 5 structured visits by trained clinicians. Diagnostic confirmation used the Conners Adult ADHD Diagnostic Interview for DSM-IV (CAADID-I) and the Diagnostic Interview for ADHD in Adults, Fifth Edition (DIVA-5), with Structured Clinical Interview for DSM-IV Axis I and II Disorders (SCID-I/II) to verify diagnoses and exclude alternatives. "However, there is currently no test or combination of tests with sufficient positive predictive value to establish the diagnosis on an individual basis," the researchers wrote.
Severity and functioning were assessed with ADHD Rating Scale (ADHD-RS), Wender Utah Rating Scale (WURS), Clinical Global Impression Severity Scale (CGI-S), Beck-II Depression Inventory II (BDI-II), State-Trait Anxiety Inventory (STAI), Barratt Impulsiveness Scale (BIS-11), Pittsburgh Sleep Quality Index (PSQI), Functioning Assessment Short Test (FAST), and World Health Organization Disability Assessment Schedule version 2.0 (WHODAS 2.0). Analyses used bivariate tests and general linear models to estimate main effects of sex and presentation and their interaction.
The study provides important context about why two functional measures gave different results. The WHODAS 2.0 provides a broader overview of disability by capturing the overall impact of functional impairments across multiple life domains. This may be particularly relevant for patients experiencing impulsivity-driven disruptions or external consequences, such as legal issues. In contrast, FAST offers a more focused assessment of specific areas of daily functioning, such as autonomy, work, interpersonal relationships, and leisure.
The researchers note that the inattentive presentation, being less externalizing than other presentations, is suggested to be the primary factor contributing to the underdiagnosis of ADHD in female patients. Patients with ADHD are estimated to have higher mortality rates, with this increase being more pronounced in females compared with males.
The discussion addresses potential biological mechanisms: hormonal fluctuations, particularly estrogen's influence on dopamine regulation, may impact emotional regulation, stress response, and executive functions in ADHD. Given that executive function and emotional regulation are crucial for managing daily life demands, hormonal effects may exacerbate disability in females with the combined subtype.
Limitations: The clinic-referred, single-program sample may have limited generalizability. The cross-sectional design precluded causal inference. Many measures were self-reported.
Strengths: The large sample size enhances the statistical power and reliability of the findings. The use of multiple validated instruments ensures a robust, multidimensional evaluation of the disorder's impact on patients.
This investigation characterized adult ADHD across sex and presentation using standardized diagnostic interviews, validated scales, and prespecified interaction testing within a structured hospital program, wrote lead study author Ferran Mestres, Department of Mental Health at Hospital Universitari Vall d'Hebron in Barcelona, Spain, and colleagues. The study described the context, instruments, and analytic framework needed for clinical interpretation without addressing treatment effects or longitudinal change.
Full disclosures can be found in the published study.
Source:European Psychiatry
