Objective: This is the first study to examine self-reported seasonal differences in the severity of ADHD symptoms in adults from the general population. Method: Data were analyzed from N = 5,303 respondents participating in the second wave of the Netherlands Mental Health Survey and Incidence Study–2, a population-based study on mental health. ADHD symptoms were assessed using the Adult ADHD Self-Report Scale Screener. As indicators of the severity of ADHD symptoms, the total ADHD symptom score and inattention and hyperactivity subscale scores were examined. Results: Compared with participants who were assessed in autumn, total ADHD and inattention subscale scores were significantly higher among participants who were assessed in spring or summer; the hyperactivity subscale score was significantly higher in spring. Conclusion: We found seasonal variations in the severity of ADHD symptoms, which was highest in those assessed in spring and summer. Researchers should be aware of this in the diagnostic process.
Vogel, S. W. N., ten Have, M. L., Bijlenga, D., de Graaf, R., Beekman, A. T. F., & Kooij, J. J. S. (2019). Seasonal variations in the severity of ADHD symptoms in the Dutch general population. Journal of Attention Disorders, 23(9), 924-930. https://doi.org/10.1177/1087054716649663