Daytime functioning in older patients suffering from chronic insomnia: treatment outcome in a randomized controlled trial comparing CBT with Zopiclone

The paper presents data from a randomized controlled trial comparing treatment effects of cognitive behavioural therapy (CBT), hypnotic treatment (Zopiclone), and placebo in a sample of insomnia patients. Data from the same trial have already demonstrated that CBT was more efficient in improving sleep than Zopiclone. The novel outcomes that are reported here concern daytime functioning.

Forty-six older patients (age55) qualifying for a diagnosis of primary insomnia were recruited to participate. Assessments were completed at baseline, post-treatment, and at a 6-months follow-up, and measures of worry, anxiety, depression, interpersonal relationships, subjective alertness, vigilance, and quality of life were used.

The participants in both treatment conditions scored within the normal range on the outcome measures at baseline with the exception of reporting less alertness, relative to a group of good sleepers. One interaction effect indicated that subjective alertness improved more in the Zopiclone group than the CBT group from baseline to post-treatment, and another that CBT was more effective than Zopiclone in reducing trait anxiety from baseline to follow-up.

It was concluded that the treatments yielded only minor effects on the measures of daytime functioning, and that none of them was clearly superior to the other.     

Night-time thoughts in high and low worriers: reaction to caffeine-induced sleeplessness

There is ample evidence for the existence of an association between sleeplessness and worry. Not much is known, however, concerning the nature of this relationship. Therefore, a study was conducted investigating the causal relationship between sleeplessness and nocturnal worry. A 2 x 2 (Worry x Induced sleeplessness) analysis of covariance design was used. The first factor consisted of a subject variable defined by scoring either high or low on a trait measure of worry (the Penn State Worry Questionnaire) and the second factor consisted of 300 mg caffeine or placebo. A total of 96 female undergraduate students participated. The dependent variables comprised measures of nocturnal worry (the Night-Time Thoughts Questionnaire) and subjective and objective sleep parameters. Overall, caffeine caused an increase in nocturnal worry and sleeplessness. A significant interaction effect occurred between Worry and Induced sleeplessness on one of the objective sleep parameters, but no other interaction effects were significant. The results suggest that worry may occur as an epiphenomenon of sleeplessness.