• People who take antidepressants show a higher weight gain than those who do not. Specifically, the increase was 1.8% in 3,127 adults who took this type of treatment at some point during the study and were followed for six years.
• The study, led by the Hospital del Mar Research Institute with the participation of the Girona Biomedical Research Institute (IDIBGI), analyzed data from participants in the REGICOR (Girona Heart Registry) study over more than six years.

A recent study led by the Hospital del Mar Research Institute and published in Frontiers in Psychiatry demonstrates the relationship between antidepressants and weight gain. In fact, by analyzing follow-up data from participants in the REGICOR (Girona Heart Registry) study, researchers were able to quantify an average weight gain of 1.8% in those taking this type of treatment. The study involved researchers from the Girona Biomedical Research Institute Dr. Josep Trueta (IDIBGI), the CIBER for Pathophysiology of Obesity and Nutrition, the CIBER for Cardiovascular Diseases (CIBERCV), Ramon Llull University, the University of Vic-Central University of Catalonia, University College London (UK), and IDIAP Jordi Gol. This is the first study of its kind conducted in Spain.

The study followed 3,127 adults over six years, 1,700 of whom were women, with an average age of 55. A total of 16.4% of participants reported taking antidepressants—some continuously throughout the study (5.1%), others starting treatment during the study (6.2%), and some taking them at the beginning but stopping during the study (5.1%). All participants gained weight over the six years (an average increase of half a kilogram), but this increase was greater in those undergoing this treatment. “All individuals taking antidepressants were more likely to gain weight and develop obesity. This risk increases among those who use these medications continuously,” explains Dr. Camille Lassale, a researcher at the Hospital del Mar Research Institute and the Barcelona Institute for Global Health (ISGlobal), a center supported by the "la Caixa" Foundation.

2% increase

The study considered the well-known bidirectional relationship between depression and obesity, as well as other associated factors, such as poor adherence to healthy diets or lack of physical exercise. However, the relationship between antidepressant use and weight gain remained significant, regardless of age, sex, socioeconomic status, lifestyle, or the presence of depressive symptoms. People who started and then stopped taking antidepressants gained an additional 1.8% weight compared to those who never took them. Those who started during follow-up or continued taking them throughout the study gained 2%. Moreover, in this last group, the risk of developing obesity doubled. Participants who used antidepressants continuously were more frequently women, older, and had an unhealthier lifestyle (diet, physical activity).

Reference article: Lassale C, Lugon G, Hernáez Á, Frank P, Marrugat J, Ramos R, Garre-Olmo J, Elosua R. Trajectories of antidepressant use and 6-year change in body weight: a prospective population-based cohort study. Front Psychiatry. 2024 Dec 24;15:1464898. doi: 10.3389/fpsyt.2024.1464898. PMID: 39777198; PMCID: PMC11703859.