Suicidal Behaviour among Persons with Attention-Deficit Hyperactivity Disorder
Cecilie Fitzgerald, Søren Dalsgaard, Merete Nordentoft and Annette Erlangsen
The British Journal of Psychiatry (2019)
Commentary* by Dr. Margaret Weiss: This truly remarkable study consolidates our understanding of the serious risks associated with ADHD.
Background: Persons diagnosed with attention-deficit hyperactivity disorder (ADHD) have been found to have an increased risk of suicidal behaviour, but the pathway remains to be thoroughly explored.
Aims: To determine whether persons with ADHD are more likely to present with suicidal behaviour (i.e. suicide attempts and deaths by suicide) if they have a comorbid psychiatric disorder.
Method: Using nationwide registers covering the entire population of Denmark, this cohort study of 2.9 million individuals followed from 1 January 1995 until 31 December 2014, covers more than 46 million person-years. All persons aged ≥10 years with Danish-born parents were identified and persons with a diagnosis of ADHD were compared with persons without. Incidence rate ratios (IRRs) were calculated by Poisson regression, with adjustments for sociodemographics and parental suicidal behaviour.
Results: Persons with ADHD were followed for 164 113 person-years and 697 suicidal outcomes were observed. This group was found to have an IRR of suicidal behaviour of 4.7 (95% CI, 4.3–5.1) compared with those without ADHD. Persons with ADHD only had a 4.1-fold higher rate (95% CI, 3.5–4.7) when compared with those without any psychiatric diagnoses. For persons with ADHD and comorbid disorders the IRR was higher yet (IRR: 10.4; 95% CI, 9.5–11.4).
Conclusions: This study underlines the link between ADHD and an elevated rate of suicidal behaviour, which is significantly elevated by comorbid psychiatric disorders. In sum, these results suggest that persons with ADHD and comorbid psychiatric disorders are targets for suicide preventive interventions.
* Abstracts are selected for their clinical relevance by Dr. Margaret Weiss, Director of Clinical Research, Child Psychiatry, Cambridge Health Alliance, Harvard University. Her commentary reflects her own opinion. It is not approved or necessarily representative of the CADDRA board.