Children and teens with attention-deficit/hyperactivity disorder (ADHD) are significantly more likely to experience depression than other children. Attention Disorder Journal.
ADHD is a neurodevelopmental condition that affects attention, impulse control, and activity levels. While these behavioral symptoms are widely known to exist, experts are increasingly recognizing that mental health issues often co-occur. Although previous studies have shown that many children with ADHD develop additional symptoms, the exact prevalence of comorbid depression in this group remains unknown.
To address this gap, researchers set out to gather existing evidence from around the world. The researchers wanted to better understand how common depression is among young people with ADHD and whether certain factors, such as age, gender, and medications, make a difference in reporting rates.
A research team led by Shipei Wang from the University of Edinburgh in the UK analyzed data from 24 rigorous studies involving a total of 6,815 children and adolescents. Of these, just over 5,000 had ADHD. Importantly, the researchers focused specifically on children with ADHD without intellectual disability, as intellectual disability can independently influence depression severity.
Participants ranged in age from early childhood to late adolescence (5 to 19 years), with an average age of less than 18 years. Although the study included both boys and girls, the majority of ADHD participants (over 76%) were boys, reflecting a long-standing gender imbalance in ADHD diagnoses.
Across included studies, depression was assessed using clinical interviews, standardized questionnaires, or a combination of both. The researchers combined these results using a statistical approach called meta-analysis. This allowed us to estimate pooled rates of depression across all studies while examining differences between subgroups.
Their findings revealed that depression is highly common among young people with ADHD. Across individual studies, reported rates varied widely, from a low of 1.7% to a high of 60%. In total, the estimated average rate was 11.31%. Importantly, seven case-control studies that directly compared the two groups found that youth with ADHD were much more likely to experience depression, about 12% compared to just 2% of neurotypical youth.
The meta-analysis also revealed significant differences between boys and girls. Girls with ADHD were found to have a much higher incidence of depression (about 21%) compared to about 9% of boys. Although this reflects gender disparities seen in the general population, the researchers noted that the severe underrepresentation of girls in ADHD research could mean that women’s rates of comorbid depression are even higher than current estimates.
Another important finding was that the method used to measure depression had a significant impact on the results. Studies that combined interviews and questionnaires tended to report the highest proportions (approximately 21%), whereas studies that relied solely on interviews reported the lowest proportions (approximately 8.4%).
Wang et al. emphasized the urgent need to develop depression assessment tools specific to the ADHD population.
“Symptoms of ADHD, such as inattention, restlessness, and irritability, may also manifest as symptoms of depression, and children and their parents may over-report depressive symptoms on standardized questionnaires designed for neurotypical populations,” the authors noted. Conversely, “the lack of validated measures specific to ADHD may result in interviewers interpreting overlapping symptoms as part of ADHD, masking and underestimating co-occurring depression,” it added.
Despite these important insights, the researchers caution that the overall pooled results should be interpreted with caution. There was significant statistical variation (heterogeneity) between studies with respect to design, sample characteristics, and assessment methods. Additionally, this review only included studies published in English, and related studies conducted in other regions may be excluded.
The study, “Prevalence of Depression in Children and Adolescents with ADHD: A Systematic Review and Meta-Analysis,” was authored by Shipei Wang, Tracy M. Stewart, Isinsu Ozen, Arnab Mukherjee, and Sinead M. Rhodes.
