ADHD Medications May Reduce Risk of Depression
Abstract
Depression is more common in youth with ADHD than in the general population.
Despite decades of prescribing stimulant medications for the treatment of attention-deficit/hyperactivity disorder (ADHD), much remains unknown about the long-term effects of these medications. Although studies show that depression in youth with ADHD occurs at a higher rate than in those without ADHD, whether ADHD medications increase or decrease this risk was unknown.
A study published last month in Biological Psychiatry suggests that ADHD medications do not increase the risk of depression; rather, they may reduce the risk of subsequent or concurrent depression.
“There is continued concern about the long-term health effects of treatment with stimulant medication,” APA Trustee R. Scott Benson, M.D., a child psychiatrist in private practice in Pensacola, Fla., told Psychiatric News. “The current study puts one of those concerns to rest.” Benson was not involved with the study.
The study was led by Zheng Chang, Ph.D., of the Karolinska Institutet in Sweden. Chang and colleagues used several population-based registers in Sweden to identify 38,752 patients with ADHD who were born between 1960 and 1998 and living in Sweden in 2009.
The researchers tracked the individuals from January 2006 through December 2009 to assess the association between ADHD medication (methylphenidate, amphetamine, dexamphetamine, and atomoxetine) and depression. The primary outcome was occurrence of depression between January 1, 2009, and December 31, 2009, including diagnoses from both hospital admissions and outpatient visits for depression. A total of 2,987 patients within the sample were reported to have had “depression events” in 2009.
After adjusting for sociodemographic and clinical confounders, the researchers found that taking ADHD medication in January 2006 was associated with a 43 percent decreased rate of depression in 2009. For each year an individual was taking ADHD medication during the study period, there was a 21 percent decrease in the rate of depression in 2009. In addition, the analysis showed that concomitant occurrence of depression was 36 percent less common during periods when patients received ADHD medications compared with periods when they did not receive medication.
“[O]ur study provided new evidence that ADHD medication does not increase the risk of later depression, but rather is associated with a reduced risk for subsequent and concurrent depression,” the researchers wrote.
David Fassler, M.D., a clinical professor of psychiatry at the University of Vermont who was not involved with the study, said that although the study represents a significant contribution to the field of psychiatry, several limitations of the study should be noted: “Diagnoses were based on patient registers as opposed to clinical assessment,” which probably only captured the most severe cases of depression that require outpatient care and hospitalization, he said. “In addition, there was no information on medication dosage, and the potential effects of non-stimulant medication were not assessed.”
Nevertheless, the current results advance what was previously understood of the relationship between stimulants and depression, Fassler said.
This study was supported by the Swedish Research Council Grant. ■
