Insomnia treatment response as a function of objectively measured sleep duration.

OBJECTIVES: To examine the potential moderating effect of objectively measured sleep duration at baseline on the response to cognitive behavioral therapy for insomnia (CBT-I), administered singly or combined with medication (CBT-I + Med). METHODS: Based on the average PSG-derived sleep duration across two baseline nights and the type of treatment received, 159 adults with insomnia (50.3 ± 10.1 years; 61.0% women) were classified into one of four groups: participants with short sleep duration (ie, ≤ 6 h) treated with CBT-I (n = 26) or CBT-I+Med (n = 25), and participants with normal sleep duration (ie, > 6 h) treated with CBT-I (n = 54) or CBT-I+Med (n = 54). Primary outcome measures were sleep/wake parameters derived from a sleep diary and insomnia severity and secondary outcomes were beliefs about sleep, fatigue, depression and anxiety. RESULTS: Patients with both short and normal sleep durations at baseline improved significantly on most sleep continuity parameters with CBT-I administered singly or combined with medication. Irrespective of treatment received, participants with short sleep duration also showed significantly greater improvements in subjective sleep (ie, reduced wake after sleep onset, increased sleep efficiency) relative to those with normal sleep duration. Conversely, participants with normal sleep duration showed greater improvements on some measures of daytime functioning and sleep satisfaction. CONCLUSIONS: There was no moderating effect of baseline sleep duration on treatment response to cognitive behavioral therapy. Despite some marginal differential treatment response on selected daytime functioning outcomes, the benefits from CBT-I were not significantly different as a function of short or normal sleep duration at baseline. Further prospective investigation of insomnia phenotypes taking into account other variables than sleep duration is warranted in order to develop more targeted insomnia therapies. TRIAL REGISTRATION: www.clinicaltrials.gov (#NCT00042146).

Familial Aggregation of Insomnia.

Study Objectives: There is little information about familial aggregation of insomnia; however, this type of information is important to (1) improve our understanding of insomnia risk factors and (2) to design more effective treatment and prevention programs. This study aimed to investigate evidence of familial aggregation of insomnia among first-degree relatives of probands with and without insomnia. Methods: Cases (n = 134) and controls (n = 145) enrolled in a larger epidemiological study were solicited to invite their first-degree relatives and spouses to complete a standardized sleep/insomnia survey. In total, 371 first-degree relatives (Mage = 51.9 years, SD = 18.0; 34.3% male) and 138 spouses (Mage = 55.5 years, SD = 12.2; 68.1% male) completed the survey assessing the nature, severity, and frequency of sleep disturbances. The dependent variable was insomnia in first-degree relatives and spouses. Familial aggregation was claimed if the risk of insomnia was significantly higher in the exposed (relatives of cases) compared to the unexposed cohort (relatives of controls). The risk of insomnia was also compared between spouses in the exposed (spouses of cases) and unexposed cohort (spouses of controls). Results: The risk of insomnia in exposed and unexposed biological relatives was 18.6% and 10.4%, respectively, yielding a relative risk (RR) of 1.80 (p = .04) after controlling for age and sex. The risk of insomnia in exposed and unexposed spouses was 9.1% and 4.2%, respectively; however, corresponding RR of 2.13 (p = .28) did not differ significantly. Conclusions: Results demonstrate evidence of strong familial aggregation of insomnia. Additional research is warranted to further clarify and disentangle the relative contribution of genetic and environmental factors in insomnia.