Longitudinal Study of Sleep and ADHD Symptoms

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CASE VIGNETTE

“Kate” is a 15-year-old Caucasian female with a history of attention-deficit/hyperactivity disorder (ADHD), diagnosed at age 7. At age 9, she reported nightmares 2 to 3 times weekly. Although her primary symptom was inattention, Kate also reported racing thoughts and a nocturnal burst of energy associated with initial insomnia more than half of nights. These symptoms improved between ages 7 and 9 with stimulant medication, but were still present. Now in high school, Kate reports a mild worsening of inattention. As her psychiatrist, how would you educate the patient and her parents about the relationship between sleep problems and symptoms in ADHD?

Sleep disturbances are a common comorbidity in ADHD, affecting approximately one quarter to one half of patients, including those who are treatment-naïve.^1,2 There is a potential bidirectional association between exacerbations of sleep disturbance and ADHD symptoms.³ Therefore, sleep disturbances appear relevant to the clinical management of ADHD. Previous studies of sleep and ADHD have focused on childhood/early adolescence,^4,5 and have not included repeated measurement of symptoms. Given that these symptoms can persist into adulthood, there is a need to understand their longitudinal relationships.

The Current Study

Gosling and colleagues⁶ investigated associations between sleep problems and ADHD symptoms in a longitudinal population-based cohort study. Among 18 million phone numbers, 7912 were randomly selected for survey. These numbers yielded 4186 eligible families, of whom 1055 (25%) were successfully recruited. Families were assessed in 3 waves (each 4 to 5 years apart), over a 9-year follow-up period. Among the enrolled families with complete data at all waves, 256 were included in the main analysis.

Parents were surveyed about ADHD symptoms using a structured interview based on the K-SADS at each wave. A structured interview based on the 2 main questionnaires for sleep disturbances in children were also used at wave 1 (28, 29). In waves 2 and 3, half of subjects had a repeat interview for sleep disturbances.

Study authors first investigated bivariate correlations between sleep disturbance and ADHD symptom scores. They then used a random-intercept cross-lagged panel model to explore longitudinal associations between sleep disturbance and ADHD symptoms, reported as regression coefficients (β) and 95% confidence intervals.

The mean subject age was 9.4 at wave 1, 13.4 at wave 2, and 18.2 at wave 3, and 52% of the sample was male. More than 80% of parents were married, and more than 50% had attended college or university. Both sleep disturbances (ρ>0.24 for each) and ADHD symptoms (ρ>0.29 for each) were significantly correlated across the 3 waves. At each wave, sleep disturbances and ADHD symptoms were significantly correlated with each other (ρ>0.14 for each). Furthermore, sleep disturbances at waves 1 and 2 were significantly correlated with ADHD symptoms at wave 3 (ρ>0.14 for each).

In cross-lagged models, sleep disturbance at wave 2 was a significant indicator of ADHD symptoms at wave 3 (β=0.15), explaining 12% of the within-person variance in ADHD symptoms. By contrast, ADHD symptoms at wave 2 did not predict sleep disturbance at wave 3. In secondary analyses, findings were stronger for inattentive (versus hyperactive-impulsive) symptoms.

Study Conclusions

The authors concluded that there is a directional association between sleep disturbance in early adolescence and ADHD symptom severity in early adulthood after considering between- and within-person effects. Findings were stronger for inattentive than hyperactive-impulsive symptoms. The primary study strength was the use of a longitudinal design with repeated assessments with consideration of directionality. Study limitations included missing data, reliance on parental reports of ADHD symptoms, and the use of telephone survey (versus in-person assessment).

The Bottom Line

This study demonstrates that sleep disturbance in early adolescence is an indicator of ADHD symptom severity in early adulthood. Findings suggest that routine assessment of sleep disturbance is warranted in patients with ADHD, and ADHD symptoms in children with sleep disturbances.

Dr Miller is a professor in the Department of Psychiatry and Health Behavior at Augusta University in Augusta, Georgia. He is on the Editorial Board and serves as the schizophrenia section chief for Psychiatric Times^TM. The author reports that he receives research support from Augusta University, the National Institute of Mental Health, and the Stanley Medical Research Institute.

References

1. Sung V, Hiscock H, Sciberras E, Efron D. Sleep problems in children with attention-deficit/hyperactivity disorder: prevalence and the effect on the child and family. Arch Pediatr Adolesc Med. 2008;162(4):336-342.

2. Cortese S, Faraone SV, Konofal E, Lecendreux M. Sleep in children with attention-deficit/hyperactivity disorder: meta-analysis of subjective and objective studies. J Am Acad Child Adolesc Psychiatry. 2009;48(9):894-908.

3. Quach JL, Nguyen CD, Williams KE, Sciberras E. Bidirectional associations between child sleep problems and internalizing and externalizing difficulties from preschool to early adolescence. JAMA Pediatr. 2018;172(2):e174363.

4. Chervin RD, Ruzicka DL, Archbold KH, Dillon JE. Snoring predicts hyperactivity four years later. Sleep. 2005;28(7):885-890.

5. Thunström M. Severe sleep problems in infancy associated with subsequent development of attention-deficit/hyperactivity disorder at 5.5 years of age. Acta Paediatr. 2002;91(5):584-592.

6. Gosling CJ, Cortese S, Konofal E, et al. Association of parent-rated sleep disturbances with attention-deficit/hyperactivity disorder symptoms: 9-year follow-up of a population-based cohort study. J Am Acad Child Adolesc Psychiatry. In press; 2022.