Magnus Landgren, Salmir Nasic, Mats Johnson, Trygve Lövoll, Daniel Holmgren, Elisabeth Fernell

Knowledge about the long-term effects on blood pressure (BP) and body mass index (BMI) when treating young patients for attention-deficit/hyperactivity disorder (AD/HD) with stimulants is limited. Most of the studies have reported mean and not individual values for anthropometrics and BP in treatment with stimulants. This seems to be the first study of changes based on the analyses of individual data measured over time. Seventy young patients (aged 8-18 years) diagnosed with AD/HD and responding well to treatment with stimulants were followed for a mean period of 3 years and 3 months. BP, heart rate, height, weight, and BMI were transformed to standard deviations or z-scores from before treatment to the last registered visit. The mean dose of methylphenidate was 0.95 mg/kg. The mean increase of systolic and diastolic BP was 0.4 z-score and 0.1 z-score, respectively. The systolic BP was associated with BMI; a higher BMI at baseline increased the risk for an increase in systolic BP. Ten percent of the total group had a weight at follow-up of <-1.5 standard deviation (SD) and 12% had a height of <-1.5 SD. Mean height at follow-up was -0.2 SD, but 40% had a reduced height of at least 0.5 SD during the treatment period. BMI on a group level was reduced from +0.8 SD to +0.3 SD. Of the 19 patients with a BMI >+1.5 SD at baseline, 50% had a significantly reduced BMI. Consequences of stimulant treatment must be evaluated individually. Besides significant effects on core AD/HD symptoms, some patients have lower BMI and BP and some increase/maintain their BMI and/or increase their systolic BP. The risk of reduced height trajectory needs further research.