THURSDAY, Oct. 23, 2025 (HealthDay News) — Antidepressants are widely used to treat depression and anxiety, but a new study finds that some of these medications can cause noticeable changes in weight, heart rate and cholesterol levels.
The study, published Tuesday in The Lancet, analyzed data from more than 58,000 participants to compare 30 different antidepressants or a placebo for an average of eight weeks.
Researchers found what they called “clinically significant” differences in how each medication affected the body’s metabolism and blood flow.
For example, people taking maprotiline gained an average of 4 pounds, while nearly half of users of amitriptyline experienced some weight gain. In contrast, agomelatine was linked to an average weight loss of 5.5 pounds among 55% of participants.
Heart rate changes also differed. Some drugs, like nortriptyline, increased heart rate by about 14 beats per minute, while fluvoxamine caused a decrease of around 8 beats per minute.
Researchers emphasized that while these findings highlight important differences, antidepressants remain effective treatments for depression and anxiety.
The results show the need for personalized prescriptions so that doctors can better match a drug to patient’s health needs.
"We do know that these medications are life-saving and life-changing, but they can have variation from person to person depending on a person's metabolism, their age (and) what other medications they're on," psychiatrist Dr. Sue Varma told CBS News after reviewing the findings.
She noted that untreated depression can also cause physical changes like weight gain or loss, so it’s important to “weigh the risks and the benefits” of starting medication.
Varma added that doctors should discuss possible side effects with patients before prescribing antidepressants and regularly monitor for any changes.
"Let's not cause panic, but these medications do have really important side effects," Varma told CBS News.
More information
The Mayo Clinic has more on antidepressants.
SOURCE: CBS News, Oct. 22, 2025