Obesity and depression are not isolated diseases.
According to a large meta-analysis published in JAMA1, obese people are 55% more likely to develop depression, and people with depression are also significantly more likely to develop obesity.
In this context, some weight-loss medications, in addition to being rising stars in diabetes and obesity intervention, have also been recognised to have the potential to improve mental health.
Past controversies, present confidence
Of course, as many GPs may recall, these medications have had a chequered past.
Initially in 2023, the European Medicines Agency (EMA) and British regulators2 launched an investigation into certain weight-loss drugs because some patients reported ‘mood swings and suicidal thoughts’.
However, in a preliminary conclusion released in 2024, the U.S. Food and Drug Administration (FDA)3 stated that ‘there is currently no evidence of a direct relationship between weight-loss medications and suicidal thoughts or behaviours.’
Another vindicating study, published in JAMA Psychiatry4 in May 2025 and involving 107,000 participants, found that compared with placebo, treatment with medications was not associated with increased risk of psychiatric adverse events.
The study states: ‘Furthermore, weight-loss medication treatment was associated with improvements in both physical and mental health–related quality of life, as well as reduced emotional eating behaviours and increased eating restraint.’
Possible mental health benefits of weight-loss medications
Medical News Today5 reports that people taking certain weight-loss medications were 45% less likely to be diagnosed with depression and 44% less likely to have anxiety compared to people not taking the drug.
Other benefits have also been found in the peer-reviewed medical journal Nature Medicine6, which states that weight-loss medication reduces the risk of addiction disorders (alcohol and tobacco), psychological disorders, epileptic seizures, and neurocognitive disorders (including Alzheimer’s disease).
In this study of 240,618 patients with obesity and 1,589,855 patients with type II diabetes:
- The results showed that the risk of suicidal ideation in the weight-loss medication group was reduced by 73% (HR 0.27).
- No suicide attempts occurred in the weight-loss medication group, while 14 occurred in the control group.
- In people with a history of suicide, the recurrence rate of suicidal ideation in the weight-loss medication group was reduced by 56% (HR 0.44), and the proportion of anti-suicidal drug prescriptions was significantly reduced.
- There was a reduction in addiction disorders (alcohol and tobacco) among participants in the weight-loss medication group.
The study was verified in a cohort of patients with type II diabetes (more than 1.58 million people), showing that weight-loss medication can also significantly reduce new and recurrent suicidal ideation, and the correlation persists in 1-year and 3-year long-term follow-up.
The connection between inflammation, obesity, and depression
It’s also theorised that some weight-loss medications may have anti-inflammatory and antioxidant properties that can help reduce neuroinflammation.7
According to the research, obesity and depression are both caused by chronic inflammation. Depressed patients often have higher levels of cytokines in their bodies8, which may in turn increase obesity and a range of other inflammatory diseases such as diabetes, asthma and cancer. Inflammation is also thought to be involved in neurological diseases such as Alzheimer’s and Parkinson’s disease.
Are there risks or side effects associated with weight-loss medications?
Melbourne bariatric and laparoscopic surgeon Dr Jason Winnett says that whilst the medications have changed lives for many of his patients, they are not ‘a magic carpet ride’.
He says, ‘Rare side effects include gastroparesis, which can cause paralysis, usually temporary, but has resulted in 1800 lawsuits in the US as of May 2025.
‘More common side effects include putting on weight again after stopping the medication, and for people with severe obesity, surgery is generally a more affordable and more viable option in the long run.’
Dr Winnett advises that any side effects must be carefully considered and weighed up against the ‘side effects’ of continuing at the current weight.
The future of obesity treatment – the mind-body link
As science continues to uncover the surprising ripple effects of weight-loss medications, these discoveries challenge us to rethink how we approach obesity – not just as a number on the scale, but as a condition deeply intertwined with the brain, behaviour, and emotional wellbeing. The future of treatment may not lie in choosing between body and mind, but in recognising that healing one often means healing both.
If your patient may benefit from a specialised assessment, consider referring them to Dr Winnett for guidance and personalised care.
Dr Jason Winnett
Laparoscopic and Bariatric Surgeon
P (03) 9417 1555 admin@winnettspecialistgroup.com.au
www.winnettspecialistgroup.com.au
Queens Terrace, 382 Victoria Parade, East Melbourne 3002
Sources:
1* Overweight, Obesity, and Depression A Systematic Review and Meta-analysis of Longitudinal Studies
2* EMA statement on ongoing review of GLP-1 receptor agonists
4* Glucagon-Like Peptide 1 Receptor Agonists and Mental Health A Systematic Review and Meta-Analysis
5* Can weight loss drugs actually help lower depression and anxiety risk?
6* Association of semaglutide with risk of suicidal ideation in a real-world cohort
7* Weight-loss jabs may be good for mental health, research shows
Additional sources:
https://www.drugwatch.com/legal/ozempic-lawsuit/
This article was reviewed by Dr Jason Winnett, AHPRA No: MED0001155541
This page contains general information only. Not medical advice. All procedures carry risks and results are individual. Consult your GP and a specialist surgeon, or seek a second opinion, before proceeding.
