How Is Adult ADHD Actually Diagnosed in Research?
- Aug 25
- 2 min read
When a study says it included “adults with ADHD,” there is an easy assumption: everyone in the trial must have been diagnosed in roughly the same way. A 2025 scoping review suggests that assumption is often wrong.
What the review examined
Researchers reviewed 292 randomized controlled trials involving adults with ADHD and asked a basic methodological question: how was the diagnosis established?
They found substantial variation and no clear consensus across studies. More than half of the trials did not appear to include an assessment of general psychopathology, and only 35% reported that the ADHD diagnosis was assigned by psychiatrists or psychologists.
Treatment evidence is only as clinically interpretable as the population that entered the study.
Why that matters
Adult ADHD overlaps phenomenologically with many other conditions. Poor concentration, procrastination, restlessness, disorganization, and working-memory complaints can occur in anxiety, depression, sleep disorders, substance use, trauma-related conditions, and medical illness.
If a study uses a narrow diagnostic process, it may enroll a population that differs from the patients a clinician sees after a comprehensive differential diagnosis. That does not make the study useless. It changes how confidently the results can be generalized.
What the review does not prove
It does not prove that the participants were misdiagnosed. It does not invalidate randomized trials of adult ADHD. And it does not establish that only one profession can diagnose ADHD correctly.
The review’s contribution is methodological: researchers and clinicians should pay attention to how diagnosis was established rather than treating the label “ADHD” as self-validating.
The clinical implication
In practice, a rigorous adult evaluation should integrate symptom history, developmental course, impairment, context, and competing explanations. Standardized scales can support that work, but diagnostic quality depends on the synthesis.