Objective: To assess how frequently drugs used to treat asthma and ADHD are prescribed to the same patients.
Method: The authors used data from the Norwegian Prescription Database for 2006, including the total Norwegian population (n = 4,640,219).
Results: Anti-asthma drugs were prescribed to 350,894 persons (7.56 % of the population), anti-ADHD drugs to 18,481 persons (0.40 %), and both to 1,730 persons. There was a 65% increased overall risk (OR = 1.65) of being prescribed one of the drugs given a prescription of the other. Women had a markedly higher risk than men. When data for each age group (10 years interval) and each gender were analyzed separately, the strongest associations were found for women between 20 and 49 years of age and men between 30 and 49 years of age.
Conclusion: These prescription patterns suggested a marked comorbidity between asthma and ADHD.