SHUTi (digital cognitive behavioral therapy for insomnia) may be more efficacious in improving sleep and reducing drinking among females with insomnia compared to males.
Key Findings
Results
SHUTi effects over time were stronger among females than males for improved sleep outcomes.
184 heavy drinking individuals with insomnia were randomly assigned to SHUTi (n=102) or an active control program (n=82)
Participants completed assessments at baseline, immediately following the 9-week intervention period, and at 3 and 6-months post-intervention
Linear mixed effects models showed sex differences in sleep outcomes with p-values ≤ 0.038
Heavy drinking was defined as weekly binge episodes of 4/5+ drinks in one sitting for females/males, AUDIT score >7, and ISI score >14
Results
SHUTi effects on reduced frequency of total and heavy drinking days were stronger among females than males.
Sex differences in alcohol consumption outcomes were statistically significant (ps ≤ 0.038)
Follow-up comparisons of within-group effect sizes revealed consistently larger reductions in alcohol consumption among SHUTi females (Cohen's d range = 0.92–2.23) than SHUTi males (Cohen's d range = 0.65–1.95)
Both total drinking days and heavy drinking days showed stronger SHUTi effects for females
The analysis combined samples from two clinical trials to increase statistical power
Results
Female SHUTi participants showed large effect sizes for reductions in alcohol consumption across the follow-up period.
Cohen's d range for SHUTi females was 0.92–2.23, indicating large to very large effects
Cohen's d range for SHUTi males was 0.65–1.95, also indicating large effects but consistently smaller than females
Effect sizes were assessed across the post-intervention, 3-month, and 6-month follow-up timepoints
Within-group comparisons were used as follow-up analyses to the linear mixed effects models
Methods
The study design combined samples from two clinical trials of a digital cognitive behavioral therapy for insomnia program (SHUTi) in heavy drinkers.
SHUTi (Sleep Healthy Using the Internet) is a digital cognitive behavioral therapy for insomnia
The intervention period lasted 9 weeks
Eligibility required weekly binge drinking episodes, AUDIT score >7, and Insomnia Severity Index (ISI) score >14
An active control program was used as the comparator condition
Data were collected at four timepoints: baseline, post-intervention, 3-month follow-up, and 6-month follow-up
Background
The relationship between poor sleep and problematic drinking appears to be stronger among females, motivating investigation of sex differences in insomnia treatment outcomes.
Poor sleep is described as a well-established risk factor for heavy drinking
No prior studies had assessed sex differences in alcohol consumption following insomnia treatment
Sleep is identified as a potential treatment target for reducing alcohol consumption
The authors note that the stronger sleep-drinking link in females provided the rationale for examining sex-specific effects
Conclusions
The findings suggest SHUTi may have sex-specific implications for prevention and treatment of heavy drinking among individuals with insomnia.
Authors conclude that SHUTi 'may be more efficacious in improving sleep and reducing drinking among females with insomnia compared to males'
Results are noted to have 'important implications for sex-specific prevention and treatment efforts for heavy drinking individuals with insomnia'
The authors frame findings within the broader context of targeting sleep to reduce alcohol consumption
Both sexes showed reductions in alcohol use, but females showed consistently larger effects
What This Means
This research suggests that a digital program designed to treat insomnia (difficulty sleeping) may also help reduce heavy drinking, and that this effect may be especially strong for women. The study combined data from two clinical trials involving 184 people who were both heavy drinkers and had insomnia. Participants were randomly assigned to use either SHUTi (an internet-based version of cognitive behavioral therapy for insomnia, a well-established non-medication sleep treatment) or a control program for 9 weeks, and were followed up for 6 months afterward. Women who used SHUTi showed larger improvements in both sleep and reductions in drinking days compared to men who used the same program, with effect sizes for alcohol reduction in women ranging from large to very large.
This research suggests that addressing sleep problems through digital behavioral therapy could be a meaningful way to also reduce heavy alcohol use, particularly among women. The finding is notable because it required no direct focus on drinking—the intervention only targeted sleep—yet drinking outcomes improved as well. Women showed effect sizes for alcohol reduction (Cohen's d up to 2.23) that were consistently higher than those seen in men (up to 1.95), even though both groups benefited.
These findings matter because heavy drinking is a significant public health concern, and effective, accessible interventions are needed. A digital insomnia program could be an accessible, stigma-reduced entry point for people who might not seek traditional alcohol treatment. This research suggests that women with both insomnia and heavy drinking patterns may be a particularly important group to target with this type of intervention, though the authors emphasize these results should inform future sex-specific prevention and treatment efforts rather than serve as definitive clinical guidance.
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Verlinden J, Moloney M, Vsevolozhskaya O, Ritterband L, Ingersoll K, Weafer J. (2026). Sex differences in sleep and alcohol consumption outcomes following a digital insomnia intervention.. Drug and alcohol dependence. https://doi.org/10.1016/j.drugalcdep.2026.113322