Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: In the study of CBT vs zopiclone for treatment of chronic primary insomnia by Dr Sivertsen and colleagues,1 I believe that there are problems relating to methodology and interpretation that limit the usefulness of their results for the medical practitioner.
The authors do not discuss a serious intrinsic bias in selecting community volunteers. Persons with insomnia may be initially seen by a physician and prescribed a hypnotic medication. For many the hypnotic may be reasonably successful and therefore continued in controlled doses regularly or episodically for years to decades. Members of this “therapeutically successful” cohort would be unlikely to volunteer for an insomnia study.
Lesser GT. Treatment of Chronic Insomnia With Cognitive Behavioral Therapy vs Zopiclone. JAMA. 2006;296(20):2435-2436. doi:10.1001/jama.296.20.2435-b