On October 6, 2026, researchers from Karolinska Institutet, Umeå University and ANOVA at Karolinska University Hospital published the first randomised trial comparing two drugs for compulsive sexual behaviour disorder (CSBD) in BMJ Mental Health. The drugs were the SSRI antidepressant fluoxetine and the addiction medication naltrexone. Eighty people meeting the diagnostic criteria were randomised to one of the two for eight weeks, followed by a six-week treatment-free period. After eight weeks there was no statistically significant difference in how much symptoms fell. Both groups improved.

Why It Matters

"Sex addiction" is a crowded market for coaching apps, accountability software and unregulated programs, and it has had very little controlled evidence on medication. A randomised head-to-head trial, even a small one, gives clinicians and digital-therapeutics companies something real to work from. In practice the treatment choice can now be made on side effects and timing rather than assumed differences in effect. For sexual-health teletherapy platforms, the faster early response with naltrexone (if it holds up) and the shared libido-dampening effect are both relevant to how care is designed and how patients are counselled. The limits matter as much as the result. With 80 participants, eight weeks and a nearly all-male sample, this is a starting point, not a treatment guideline. No drug is approved specifically for CSBD, and the researchers say larger and longer studies are needed.

The difference was in timing. Per Karolinska's release, people on naltrexone improved early, while improvement on fluoxetine came later in the treatment period. Lead author Josephine Savard cautioned that the trial "was not designed to investigate such differences" and that the speed finding should be treated as preliminary. Most participants reported side effects, generally mild to moderate. Reduced sexual desire showed up in both arms, nausea was more common with naltrexone, and two fluoxetine patients stopped because of pronounced or severe adverse effects. The authors note that the sample was almost entirely men, so the results cannot automatically be applied to women.

The context is a condition with no drug built for it. CSBD was recently classified as a disorder by the WHO and is estimated to affect 2–3% of the population, according to Umeå University. Co-author Jussi Jokinen said SSRIs are usually considered first-line because they reduce impulsivity and compulsive thoughts, while naltrexone is used because the condition's neurobiology overlaps with other addictive disorders. The team took extensive biological samples and says its next step is looking for clinical and neurobiological predictors of which patients respond to which drug.

Sources

Update — 2026-10-12

Initial entry — story first created.