Evaluating the Link Between Shorter Height and ADHD Medication

Shorter height in men with ADHD may be related to factors besides medication use, such as genetics or somatic conditions.

Attention-deficit/hyperactivity disorder (ADHD) was associated with shorter height in men both before and after wide medication availability, according to authors of a Swedish study published in the Journal of the American Academy of Child & Adolescent Psychiatry.

Although treatment with ADHD medications has been commonly associated with growth deficits, growth studies conducted during ADHD treatment have yielded conflicting findings. These variable results suggest that, in addition to medication use, other factors, such as genetics or somatic conditions, may play a role in the association between ADHD and shorter stature.

Investigators sourced data for the study from multiple Swedish National Registers. Men (n=14,268) diagnosed with ADHD between 1987 and 2001 who participated in Swedish military conscription between 1968 and 2010 were evaluated for somatic conditions, mental health comorbidities, parental education, and height. Treatment-naive cases were defined as individuals who conscripted between 1968 and 1991, before ADHD medications were available in Sweden. The potential ADHD medication use-cases conscripted between 1992 and 2010. Each case was matched with up to 5 comparators (all men, who also had to participate in the Swedish military conscription and were matched for birth year and county), for a total of 71,339 controls.

The mean (SD) height was 178.51 (6.74) cm for potential ADHD medication use-cases at conscription, and 179.47 (6.57) cm for patients in the control group at conscription. Among the patients, 44.62% and 4.04% had substance use disorder (SUD), 42.75% and 3.30% had depression, 11.97% and 0.51% had anxiety disorder, and 1.63% and 1.20% had inflammatory bowel disease, respectively. Stratified by time periods before vs after the availability of ADHD medication, height at conscription in the “premedication” treatment-naive sample was similar between cases vs controls. The mean (SD) height was 178.12 (6.60) cm for individuals with ADHD, and 179.27 (6.51) cm for patients in the control group. Using a family-based design, the investigators also evaluated 833,172 male relatives without ADHD who had different degrees of relatedness to the men with ADHD and the matched controls.

We found that the association between ADHD and shorter height was similar in magnitude in a treatment-naive cohort and a potentially treated cohort.

Compared with individuals who were 173-185 cm tall at conscription (ie, average height), in both the pre- and postmedication period, men with ADHD were more likely to be 150-165 cm (height far below average; odds ratio [OR] range, 1.55-1.58) or 166-172 cm (below average height; OR range, 1.21-1.31) tall at conscription and less likely to be 186-192 cm (above average height; OR range, 0.81-0.88) or 193-209 cm (far above average height; OR, 0.65-0.85) tall compared with controls. The trend for ADHD to be associated with shorter than average height remained consistent but partially attenuated after adjusting for birthweight, somatic conditions, mental health conditions, and parental education (adjusted OR range, 1.11-1.58).

When cases and controls were paired with their male relatives, the investigators found that full siblings of the cases were also more likely to be shorter than average (OR range, 1.14-1.18) and less likely to be taller than average (OR range, 0.89-0.90) compared with siblings of controls. These trends were consistent in the analyses that used paternal half-siblings and full first cousins. The analysis that used maternal half-siblings tended to follow a similar pattern.

Study limitations include lack of clarity regarding whether the participants had reached their final adult height at the time of military conscription.

The study authors concluded, “We found that the association between ADHD and shorter height was similar in magnitude in a treatment-naive cohort and a potentially treated cohort. The associations between ADHD and shorter height were partly explained by [socioeconomic status], prenatal factors, and psychiatric comorbidity. Family-based analyses further indicated a shared familial liability between ADHD and shorter height.”

Disclosures: Several study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

References:

Ahlberg R, Garcia-Argibay M, Rietz ED, et al. Associations between attention-deficit/hyperactivity disorder (ADHD), ADHD medication and shorter height: a quasi-experimental and family-based study. J Am Acad Child Adolesc Psychiatry. Published online April 18, 2023. doi:10.1016/j.jaac.2023.03.015