There does not appear to be a causal association between methylphenidate hydrochloride treatment for attention-deficit/hyperactivity disorder (ADHD) and suicide attempts, according to a study in JAMA Psychiatry.
The researchers examined 25,629 patients age 6 to 25 who received at least one prescription for methylphenidate and made at least one suicide attempt during a 15-year period ending December 31, 2015.
Data was drawn from the Clinical Data Analysis & Reporting System (CDARS), an electronic health record database developed by the Hong Kong (HK) Hospital Authority, China. The service covers about 80% of all hospital admissions in HK.
There were 19 patients excluded from the study because they attempted suicide before the observation period started. Of the study cohort, 154 patients had their first recorded suicide attempt within the observation period; 111 (72.1%) were male and 43 (27.9%) female.
The mean (SD) age at commencement of observation was 7.15 (2.19) (range 6.0 to 16.47) and the mean duration of follow-up was 12.15 (2.82) years.
Mean (SD) methylphenidate exposure was 2.22 (2.33) years. The median length of each prescription was 70 days (interquartile range 35-105 days; range 1 to 1023 days). Short-acting forms of the drug were written in 3617 of 4300 prescriptions (84.1%).
The overall incidence of suicide attempts during methylphenidate treatment was 9.27 per 10,000 patient-years, and the highest number of suicide attempts occurred immediately before the start of methylphenidate treatment. The risk then remained elevated immediately after the start of treatment and returned to baseline levels during continuation of methylphenidate treatment.
When the risk during the first 90 days of treatment was compared with the 90 days preceding the first treatment, the incidence of suicide attempts was not elevated (incidence rate ratio 0.78; 95% CI 0.26-2.35).
Man KKC, Coghill D, Chan EW et al. Association of Risk of Suicide Attempts with Methylphenidate Treatment [published online July 26, 2017]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2017.2183