Sleep problems are common in infancy. Some infants are prescribed sleep-inducing drugs even if not approved for the age group. Poor sleep as toddler is a risk factor for development of behavioral problems in childhood. It is unknown if this is true also for attention deficit and hyperactivity disorder (ADHD).

To evaluate two sources of information on toddler drug use (mother-reported questionnaire-data and prescription database for hypnotic drugs for children aged 0–18 months) and see if these predict receiving a later diagnosis of ADHD.

Are sleeping problems as measured by the use of hypnotics in toddlers a risk factor for ADHD?

Prescription database information data was collected for 47,413 children participating in the Norwegian Mother and Child Cohort, where mothers report on toddler drug use. These two datasets were used as predictors of diagnoses of ADHD as seen in the Norwegian Patients Registry in a 7-year follow up period.

Agreement between mother-reported drug use and hypnotics use as measured was less than 50% for all hypnotics (min 19% and max 48%). The two datasets will be further used to investigate the relationship between toddler drug use and a later childhood diagnosis of ADHD.

Considering the low to moderate agreement between mother-reported survey data and data from prescription databases it is of value to use both data sources in a study looking at the predictive value of sleeping problems and hypnotics use in toddlers on later development of ADHD.

The authors have not supplied their declaration of competing interest.