Summary: A large observational study from the University of Oxford finds that semaglutide (commonly known as Ozempic or Wegovy) does not harm brain health over 12 months and is linked with lower rates of cognitive problems and nicotine dependence. The analysis, which examined electronic health records from more than 100 million patients in the United States—including over 20,000 people prescribed semaglutide—found no increased risk of neurological or psychiatric conditions compared with other widely used antidiabetic drugs.
These results suggest semaglutide’s effects may extend beyond blood sugar control, though randomized trials are needed to confirm the potentially protective associations the researchers observed.
Key facts:
- No increased risk: Semaglutide was not associated with higher rates of neurological or psychiatric diagnoses over 12 months compared with sitagliptin, empagliflozin, or glipizide.
- Possible benefits: The drug was linked to reduced risk of cognitive impairment and lower rates of nicotine dependence in several comparisons.
- Large dataset: The study used electronic health records from a US network of over 100 million patients, including more than 20,000 people treated with semaglutide.
Source: University of Oxford
Overview
Researchers at the University of Oxford, supported by the National Institute for Health Research (NIHR) Oxford Health Biomedical Research Centre and the Medical Research Council, conducted a retrospective cohort study to examine neurological and psychiatric outcomes among people with type 2 diabetes who were prescribed semaglutide. Published in eClinicalMedicine, the study compared patients taking semaglutide with matched groups prescribed sitagliptin, empagliflozin, or glipizide.
Using records contained in the TriNetX US Collaborative Network, the investigators created three propensity-score matched cohorts of people with type 2 diabetes who began semaglutide between 1 December 2017 and 31 May 2021. Each semaglutide cohort was matched 1:1 to people prescribed one of the comparator drugs (sitagliptin, empagliflozin, or glipizide) to reduce confounding and make groups comparable on measured characteristics.
The team assessed the relative risks of 22 neurological and psychiatric outcomes within 12 months of the index prescription. Outcomes included cognitive deficit, dementia, epilepsy, stroke, various substance misuse diagnoses (including nicotine dependence), mood and anxiety disorders, psychosis, and suicidality. Negative control outcomes were also examined to check for unmeasured confounding.
Across matched comparisons, cohort sizes were substantial: 23,386 patients in the semaglutide versus sitagliptin match, 22,584 versus empagliflozin, and 19,206 versus glipizide. The main finding was consistent: semaglutide did not increase risk for the neurological or psychiatric outcomes studied during the 12-month follow-up.
After adjusting for multiple testing, several outcomes showed lower risk among semaglutide-treated patients. Notable associations included reduced incidence of cognitive deficit compared with sitagliptin and glipizide (hazard ratios ~0.72) and lower dementia risk versus sitagliptin (hazard ratio ~0.52). Semaglutide was also associated with reduced rates of nicotine misuse across most comparisons, though one comparison lost statistical significance after multiple-test correction. Empagliflozin showed the fewest differences compared with semaglutide. No differences emerged in negative control outcomes.
The authors caution that the study is observational and cannot establish causation. Potential explanations for the associations—whether direct neuroprotective effects, indirect benefits from improved metabolic control or weight loss, or other unmeasured factors—remain uncertain. The investigators call for randomized controlled trials to validate and extend these findings.
Lead author Dr Riccardo De Giorgi noted that if these results are replicated, semaglutide might have broader public health implications by helping reduce cognitive decline and smoking rates among people with diabetes. Senior author Dr Max Taquet emphasized that the findings should be confirmed in randomized studies but are reassuring for patients treated with semaglutide.
About this neuropharmacology research news
Author: Riccardo De Giorgi
Source: University of Oxford
Contact: Riccardo De Giorgi – University of Oxford
Image credit: Neuroscience News
Original research: Open access. “12-month neurological and psychiatric outcomes of semaglutide use for type 2 diabetes: a propensity-score matched cohort study” by Riccardo De Giorgi et al., published in eClinicalMedicine.
Abstract
12-month neurological and psychiatric outcomes of semaglutide use for type 2 diabetes: a propensity-score matched cohort study
Background
Semaglutide is an approved treatment for type 2 diabetes and is being explored for potential benefits in brain disorders. Concerns about possible neuropsychiatric side effects have prompted a need for large-scale, population-based studies to better define its safety profile for neurological and psychiatric outcomes.
Methods
This retrospective cohort study analyzed electronic health records from the TriNetX US Collaborative Network, covering more than 100 million patients. Patients with type 2 diabetes who initiated semaglutide between December 2017 and May 2021 were matched 1:1 by propensity score to patients initiating sitagliptin, empagliflozin, or glipizide using a greedy nearest-neighbour algorithm. Cox regression models estimated hazard ratios for 22 predefined neurological and psychiatric outcomes within 12 months of the index prescription; negative control outcomes were used to probe residual confounding.
Findings
Matched cohort sizes were 23,386 (semaglutide vs sitagliptin), 22,584 (vs empagliflozin), and 19,206 (vs glipizide). Semaglutide was not linked to an increased 12-month risk of neurological or psychiatric outcomes. Instead, after multiple-testing correction, semaglutide was associated with lower risk of several outcomes—most notably cognitive deficit and dementia in specific comparisons, and reduced nicotine misuse across most comparator groups. Empagliflozin showed the fewest differences when compared with semaglutide. No differences were observed for negative control outcomes.
Interpretation
In this large real-world cohort, semaglutide did not increase short-term risk for adverse neuropsychiatric outcomes compared with other common antidiabetic medications. Observed associations suggesting potential benefits for cognitive impairment and nicotine dependence warrant confirmation in randomized clinical trials to determine causality and underlying mechanisms.
Funding
National Institute for Health Research (NIHR) Oxford Health Biomedical Research Centre; Medical Research Council.