Could a Diabetes Drug Help Stabilize Mood in Bipolar Disorder?

The list of everything semaglutide appears to affect continues to expand. Originally approved for type 2 diabetes, then reshaped into a household name through Ozempic and Wegovy for weight management, this GLP-1 medication has spent the past few years accumulating an unusual reputation, with possible GLP-1 benefits that keep showing up in research on conditions that have nothing obvious to do with blood sugar or body weight. And now, a new entry on that list is one I did not expect: bipolar disorder.

A newly published study out of Griffith University in Australia adds real weight to that pattern. Based on data from 15 years of national health registries in Sweden, they report that individuals with bipolar disorder have a significantly reduced rate of psychiatric hospitalization while on semaglutide compared to while not on the drug. This is an early finding, not a green light for a new use; it’s just worth knowing what has researchers excited.

Why Bipolar Disorder and Metabolic Health Keep Showing Up Together

Bipolar disorder is not a particularly uncommon condition. But it’s not as widely known that bipolar disorder is frequently comorbid with type 2 diabetes and obesity. And that co-occurrence is no accident: Increasingly, researchers believe that bipolar disorder, diabetes and obesity have overlapping biological underpinnings that may include inflammation and cellular stress.

It’s precisely because of that shared physiology that the medication was already under consideration as an experimental treatment for bipolar disorder. If those cells, or the biological pathways associated with the condition, are affected by medications like GLP-1s, there is certainly room to explore how the two might affect each other.

Inside the Griffith University Study

To carry out the study, Prof. Mark Taylor and his colleagues leveraged one of the strengths of Sweden’s national health care system: its highly comprehensive registries, which enable researchers to follow the medication use and hospitalisations of an entire population for many years. They found nearly 15,000 people with bipolar disorder who were, at some point during a 15-year period, prescribed a GLP-1 drug.

Instead of comparing those who took GLP-1 medications with those who did not, they analyzed data from the same person, looking at periods when semaglutide was prescribed versus periods when it wasn’t. This methodological approach controls for some of the confounding factors that usually plague this type of study, because everyone’s data was compared with their own.

The result: during the periods when participants were taking semaglutide, their risk of psychiatric hospitalization was 21% lower than during the periods when they weren't on the drug.

Not a Class-Wide Effect

Now things get a little less definite, and a little more interesting. Not all GLP-1 medications in the dataset had the same benefit. Two other well-known GLP-1 drugs, liraglutide and dulaglutide, did not appear to be associated with lower rates of hospitalization.

That's a genuinely useful clue for researchers, because it suggests whatever is happening here probably isn't a blanket feature of "GLP-1 drugs" as a category. Something more specific to semaglutide, its particular receptor binding profile, its dosing, or some other pharmacological detail, may be doing the heavy lifting. Untangling that distinction is likely to be a major focus of follow-up research.

A Plausible, Still-Unproven Mechanism

So how might a diabetes and weight-loss drug influence something as complex as the mood swings and instability of bipolar disorder, and where do GLP-1 medications fit in? The most popular theory has to do with the brain and its response to inflammation. GLP-1 receptors aren't confined to the gut and pancreas, they're also present in areas of the brain involved in mood regulation. There’s also a chance that semaglutide’s anti-inflammatory and anti-oxidant effects, and perhaps other properties too, reach into parts of the brain that regulate emotions and may help keep people’s mood balanced in the long run.

That’s a nice idea, but it’s still only an idea at this point, one backed up by a correlation in observational data, not a causal relationship demonstrated through experimental study. A study can show that the rate of hospitalizations fell while semaglutide was being used; it cannot show that semaglutide caused that reduction, as opposed to something else that coincidentally occurred at the same time as people started getting prescribed it.

What Would Need to Happen Next

Professor Taylor and his team have pointed out that before the finding is accepted and used as fact, it will need to be evaluated in a randomised controlled trial. Observational evidence from medical records, however strong, can only point towards a hypothesis. Randomisation is required to establish causality. To know whether the drug is actually responsible for the effect, patients must be assigned at random to receive semaglutide or a placebo or alternative treatment.

Until that kind of trial exists, this research belongs in the "promising and worth watching" category rather than the "proven treatment" category. The study appears in Acta Psychiatrica Scandinavica, and it's likely to spark follow-up research given how striking a 21% reduction is for a drug that wasn't designed with psychiatric outcomes in mind.

What This Might Mean for You

If you live with bipolar disorder and also manage type 2 diabetes or a weight-related condition, this research is a reasonable thing to mention at your next appointment, not as a request to start semaglutide for mood reasons, but as a data point worth discussing if a GLP-1 medication is already relevant to your care. Your psychiatric treatment plan should continue to be guided by your psychiatrist or care team, not by an early observational study, however encouraging the numbers look.

This is another good reason to keep your entire team of providers up to speed on all medications you’re taking from all doctors. The connection between metabolic and mental health issues is deeper than many people understand, and having everyone involved in your treatment take a holistic look at your care often identifies issues that an individual doctor may miss.

Key Takeaways

• A 15-year Swedish study of nearly 15,000 people with bipolar disorder found a 21% lower risk of psychiatric hospitalization during periods of semaglutide use.

• Finally, bipolar disorder, diabetes and obesity might be linked via biological mechanisms like inflammation and oxidative stress that could also play a role in these conditions.

• This effect was observed only with semaglutide; the other two GLP-1 medications evaluated, liraglutide and dulaglutide, were not associated with such risk.

• These are observational data, not a randomized controlled trial, so we can only conclude that there’s an association here, not that semaglutide is what causes improved psychiatric outcomes.

• Anyone considering how this research might apply to them should raise it with their psychiatrist or prescriber, not use it as a basis for changing treatment independently.

Frequently Asked Questions

Is semaglutide now a treatment for bipolar disorder?

No. This research shows an association between semaglutide use and lower psychiatric hospitalization rates, but it doesn't establish the drug as a bipolar disorder treatment. The researchers themselves say a randomized controlled trial would be necessary to make such a claim.

Why would a diabetes drug affect a psychiatric condition at all?

Researchers speculate that diabetes, bipolar disorder and obesity have overlapping mechanisms, including inflammation and oxidative stress. And because GLP-1 receptors exist in parts of the brain related to mood, semaglutide’s potential benefits for the brain could be caused by its anti-inflammatory properties.

If my other GLP-1 medication didn't show this effect, does that mean it's not working for me?

Nope. Liraglutide and dulaglutide are great medications for their approved indications for diabetes and weight loss. They just weren't associated with psychiatric hospitalization in this study. That doesn't mean they aren't good medications for treating the diseases they are approved for.

Please note that this article is only for educational purposes and is not a replacement for personalized medical advice. If you have bipolar disorder or other mental illness, please stay in touch with your psychiatrist or care team and discuss any modifications to your treatment before implementing them.