Used primarily for the treatment of diabetes, GLP-1 type drugs have now become essential for patients seeking to lose weight. Widely used in the United States, Ozempic and other drugs of this type have well-known side effects such as nausea, fatigue or digestive problems. But in addition to these physical symptoms, some doctors notice a change in the psychological state of some patients.
Several users describe a “extreme apathy”: no sadness, no enthusiasm. Psychologist Sera Lavelle talks about a missing spark: a loss of interest in previously enjoyable activities, a lack of motivation or indifference to things that previously sparked joy or excitement. This phenomenon is not classic depression – patients do not feel “at rock bottom” – but rather an inability to take pleasure.
This observation, described by Vox, is not yet confirmed by large clinical studies, but researchers already have a theory. GLP-1 would modify brain circuits linked to dopamine and reward, going beyond simply regulating appetite by influencing the feeling of satiety. The same circuits involved in the desire to eat can also be used for social motivation, to give interest to personal projects or to experience pleasure in human relationships.
For some patients, especially those with severe eating disorders, this reduction in reward signals may be beneficial. Indeed, it reduces mental noise around food and helps regain control. But for those without appetite problems, the molecule can produce a feeling of detachment, as if life is losing interest.
The researchers emphasize the importance of differentiating this effect from depression because, in the cases observed, it is not a loss of the will to exist, but rather a lack of feeling towards desires and motivations, which can affect both food cravings and other forms of engagement such as gaming, going out, etc. This nuance is essential to understand the potential psychological impact of GLP-1, especially now that their use is becoming more widespread.
The scientific debate remains open. Some experts see this side effect as a possible consequence of the modulation of the brain’s reward circuits, but point out that it is too early to draw firm conclusions without further, broader research.
