An online insomnia course lowered depression symptoms, but did not prevent new major depression
In 1,149 adults with insomnia and low mood, six weeks of online CBT for insomnia lowered depression scores at six weeks and six months against a placebo program. New major depression: 9 against 13 cases, not different. 44% finished.
Well-supported by good-quality research. how we score evidence
Caveat on this rating: Forty-four percent follow-up at six months is a serious limitation and the abstract states it. The prevention question the trial was named for returned a null that the trial was too small to answer (22 cases). The symptom result stands against an attention-matched placebo, which is a fair comparison, but it is a symptom score, not a diagnosis.
Insomnia and depression travel together. This trial asked whether treating the insomnia could stop the depression from developing.
Significant findings
Christensen, Batterham, Gosling and colleagues ran the GoodNight Study from the Australian National University. Between April 2013 and June 2014 they randomised 1,149 internet users aged 18 to 64 who had insomnia and depression symptoms but did not meet criteria for major depressive disorder. Half (574) received SHUTi, a six week online program based on cognitive behavioural therapy for insomnia. Half (575) received HealthWatch, "an interactive, attention-matched, internet-based placebo control program." Interviewers, statisticians and chief investigators were masked.
On symptoms the course worked. "SHUTi significantly lowered depression symptoms on the PHQ-9 at 6 weeks and 6 months compared with HealthWatch."
The other direction
On diagnoses it did not. "Major depressive disorder was diagnosed in 22 (4%) participants at 6 months (n=9 in the SHUTi group and n=13 in the HealthWatch group), with no superior effect of SHUTi versus HealthWatch (Fisher's exact test=0·52; p=0·32)."
Attrition was heavy: 581 people (51%) completed the six week assessments and 504 (44%) completed six month follow up. "No adverse events were reported."
The authors still conclude that online CBT for insomnia "is a practical and effective way to reduce depression symptoms and could be capable of reducing depression at the population level."
What this does not show
With 22 new cases in total, the trial was not large enough to show a difference in who developed major depression, so the null on diagnoses is uninformative rather than negative. Fewer than half of participants finished, which weakens every estimate. The effect is on symptom scores, against a genuinely matched placebo program, which is a stronger comparison than usual care.
Worth asking
If my sleep and my mood are both poor, which one are we treating first, and why?
Source
Effectiveness of an online insomnia program (SHUTi) for prevention of depressive episodes (the GoodNight Study): a randomised controlled trial — Christensen H, Batterham PJ, Gosling JA, Ritterband LM, Griffiths KM, Thorndike FP, Glozier N, O'Dea B, Hickie IB, Mackinnon AJ (2016)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1016/S2215-0366(15)00536-2
DOI: 10.1016/S2215-0366(15)00536-2
How this was scored
- Study design
- Randomised controlled trial
- Funding
- Independently funded
- Published in
- Top-tier peer-reviewed journal
- Sample size
- 1,149
- Preregistered
- Yes
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published September 24, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "strong evidence". Well-supported by good-quality research. It scores 84 out of 100 on our published rubric. One caveat travels with that badge: Forty-four percent follow-up at six months is a serious limitation and the abstract states it. The prevention question the trial was named for returned a null that the trial was too small to answer (22 cases). The symptom result stands against an attention-matched placebo, which is a fair comparison, but it is a symptom score, not a diagnosis. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Effectiveness of an online insomnia program (SHUTi) for prevention of depressive episodes (the GoodNight Study): a randomised controlled trial — Christensen H, Batterham PJ, Gosling JA, Ritterband LM, Griffiths KM, Thorndike FP, Glozier N, O'Dea B, Hickie IB, Mackinnon AJ (2016). Published in: Top-tier peer-reviewed journal. DOI: 10.1016/S2215-0366(15)00536-2. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Randomised controlled trial. Funding: Independently funded. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.