Intervention
Cognitive behavioural therapy for insomnia (depression-prevention trial protocol)
Research Observatory
Evidence Update
Current evidence
In older adults with insomnia and no major depression during the previous year, cognitive behavioural therapy for insomnia reduced new or recurrent major depression compared with sleep education. Follow-up was extended from 24 to 36 months, and retention differed between groups, especially at 24 months. Those limitations matter, and an association between sustained sleep improvement and depression does not prove how the treatment worked.
What changed
Cognitive behavioral therapy for insomnia reduced incident or recurrent major depression relative to sleep education in this older insomnia cohort.
How to read these findings
Random assignment supports the treatment comparison. An association between later sleep improvement and depression does not prove that sleep improvement caused the depression result.
Retention means the proportion of participants who remained in follow-up. Unequal loss to follow-up can affect interpretation; the exact 24- and 36-month figures are preserved below.
Accepted limitations and study details
Exact reviewed qualifications are retained below. These details do not add a new accepted claim.
Study interpretation and limitations
- 24-month completion 73.1% versus 86.7%; 36-month retention 51.9% versus 57.0%.
- Sustained-remission associations are not randomized mediation evidence.
- Design: Randomized active-control trial
- Safety: Attrition differs by arm; no comprehensive adverse-event claim from the abstract.
- Interpretation: Randomized depression effect differs from post-randomization insomnia-remission association.
Why it matters
These findings apply to the studied populations, regimens and outcomes; they do not establish generalized longevity benefit.
Next proof
Independent replication with attrition-sensitive estimates and longer follow-up.