The mortality risk rises across the spectrum of ADHD severity, much like blood pressure or cholesterol
STUDY: Thapar A et al, British Journal of Psychiatry 2026
STUDY TYPE: Secondary analysis of a population birth cohort (observational study)
FUNDING: Independent
Background
ADHD referrals have surged across the UK and Europe, and waiting lists, roughly 700,000 people in England alone, have prompted calls to limit assessment and treatment to the more severe cases. This paper looks at whether “milder” symptom levels still carry a significant health risk.
The Study
- A reanalysis of the 1958 British birth cohort, following participants to age 58.
- Parent (Rutter A Scale) and teacher symptom ratings at age 7 were combined into an ADHD symptom score from 1 to 8.
- Each score level, not just a full diagnosis, was checked against premature mortality.
Results
Every score level except the single mildest one, a score of 1, was tied to higher mortality. Risk rose with the score: the odds ratio was 1.4 (95% CI, 1.1-1.6) at a score of 2, which covered 18% of the cohort, climbing to 2.6 (95% CI, 1.3-5.3) at the highest score of 8, covering just 0.5% of the cohort. Mortality risk rose with symptom severity in a graded pattern, not only in the small group who would have met full diagnostic criteria.
Limitations
This cohort was born in 1958 and grew up without ADHD diagnosis or treatment, so the findings may not generalize to a treated population today. Symptom scores came from decades-old parent and teacher ratings, not a validated diagnostic interview. The highest-risk group included only 66 people, limiting precision at the severe end.
Practice Implications
- Mild symptoms can lead to major problems when they occur every day for years on end.
- We learned a similar truth with dysthymic disorder, a “mild” chronic depression that causes more disability than episodic major depression.
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
