A low dose of buprenorphine following a ketamine session may provide a longer-lasting anti-suicidal effect

There is a new scientific article in the American Journal of Psychiatry published on a combination treatment involving ketamine and low-dose buprenorphine in people with severe depression and suicidal thoughts.

The following was found in it:

Evidence suggests that a short course of low-dose buprenorphine, started following a single ketamine infusion, can significantly prolong and enhance the reduction in suicidal thoughts, without having any additional effect on depressive symptoms as a whole.
In other words: ketamine brings about a rapid reduction in suicidal ideation, and buprenorphine appears to help sustain that effect for longer.

The research

The researchers wanted to find out whether the short-term anti-suicidal effect of ketamine could be prolonged with additional medication. Ketamine is known for its rapid, but often temporary, reduction in suicidal thoughts, with a clear effect usually observed in the first few days to a week after administration.

This randomised, double-blind, placebo-controlled study involved 50 adults with major depressive disorder (MDD) and clinically significant suicidal ideation. All participants first received a single intravenous ketamine infusion (0.5 mg/kg over 40 minutes, open-label). Approximately 48 hours later, they were randomly assigned to either low-dose buprenorphine (0.2–0.8 mg/day sublingually) or a placebo for 4 weeks.

Of the 50 participants, 45 completed at least one week of follow-up treatment and were included in the primary analysis. Over the course of the 4 weeks, questionnaires on suicidal ideation and symptoms of depression were administered repeatedly, enabling the researchers to compare the progression of symptoms between the ketamine+buprenorphine group and the ketamine+placebo group.

It is important to emphasise that ketamine rapidly and significantly reduced suicidal thoughts in both groups. The key question of this study was therefore not whether ketamine works, but whether low-dose buprenorphine can provide additional and more lasting benefits on top of that in people who have already received a ketamine infusion.

The results showed that both groups experienced a significant reduction in suicidal ideation, but that the reduction in the ketamine plus buprenorphine group was clearly greater. Over the four weeks, the score on a standard measure of suicidal thoughts fell by an average of approximately 11.6 points in the buprenorphine group, compared with 6.3 points in the placebo group (Glass’s delta effect size around 0.76).

After four weeks, this amounted to a reduction in suicidal ideation of approximately 76% in the ketamine+buprenorphine group, compared with approximately 43% in the ketamine+placebo group. A large proportion of participants in the buprenorphine group were below the threshold for clinically significant suicidal ideation, whilst a significant proportion in the placebo group were just above it.

Interestingly, the researchers found no significant differences between the groups in terms of general symptoms of depression. Although depression improved in both groups, the additional benefit of buprenorphine appeared to be specifically targeted at suicidal thoughts, rather than depressive mood or other depressive symptoms as a whole.

With regard to safety, no serious adverse events occurred that were directly attributed to the treatment. The doses of buprenorphine used were low, and the reported withdrawal symptoms and side effects following discontinuation were minimal. This supports the view that this sequential treatment may be relatively well tolerated in a carefully supervised clinical setting.

The authors conclude that this ketamine–buprenorphine combination is the first pharmacological strategy to demonstrate, in a randomised trial, that ketamine’s anti-suicidal effect can be sustained for at least one month. At the same time, they emphasise that further studies are needed to better understand the optimal dosage, duration, long-term safety and applicability in wider populations.

Our view on this study

Our view of this study is that it represents an important step towards more structured strategies for prolonging the short-term anti-suicidal effect of ketamine. Until now, the focus has mainly been on repeated ketamine infusions or psychotherapeutic follow-up; this study shows that a complementary pharmacological approach using low-dose buprenorphine may be a viable and potentially scalable option.

As with research into psilocybin and other psychedelics, we are seeing a shift here from focusing solely on acute effects to exploring how those effects can be made long-lasting. Whilst psilocybinstudies often examine neuroplasticity, inflammatory markers or epigenetic changes, this ketamine–buprenorphine study shows that the choice and timing of follow-up medication can also be crucial in determining how long a rapid intervention provides protection against suicidal thoughts.

This study therefore forms part of a broader trend: away from exclusively long-term courses of antidepressants with a slow onset of action, towards combinations of rapid interventions (such as ketamine) with targeted maintenance strategies. In clinical practice, this could mean in future that people with acute suicidal ideation are first rapidly stabilised with ketamine, and that a carefully dosed course of buprenorphine then helps to consolidate these gains, naturally within the framework of addiction risks and strict monitoring.

At the same time, caution remains important. The sample is relatively small and specific (MDD with suicidal ideation, without severe substance use disorders), and the follow-up period is limited. The study does not prove that buprenorphine improves depression as a whole, and the use of an opioid-like drug in vulnerable patients always requires careful consideration of the risks of dependence and the need for monitoring.

In one sentence: this article shows that a short ketamine infusion, followed by four weeks of low-dose buprenorphine, can significantly prolong the reduction in suicidal ideation in people with severe depression and suicidal thoughts, but that this is still an early step – one that must be interpreted with caution – in the search for more sustainable anti-suicidal treatments.