- Antidepressants are a common group of medications that help treat a variety of mental illnesses.
- Doctors must consider potential side effects when prescribing a particular antidepressant.
- Recent studies have highlighted weight changes associated with some antidepressants.
- Bupropion was associated with the least amount of weight gain, while antidepressants such as escitalopram and paroxetine were associated with the most weight gain.
All medications have potential risks and sometimes unpleasant side effects. Physicians must consider possible side effects and how these effects may affect outcomes such as medication adherence.
Antidepressants are a group of medications commonly used to treat chronic mental illnesses, especially severe depression. Certain antidepressants can reportedly cause weight gain as a side effect.
According to a recently published study, Annals of Internal Medicine We looked at weight changes associated with several common antidepressants.
Throughout the study of 183,118 participants, researchers found that those taking bupropion (brand name Wellbutrin) were the least likely to experience weight gain, while those taking escitalopram (Lexapro, Cipralex), paroxetine (Paxil, Seroxat), and duloxetine (Cymbalta) were the most likely to experience weight gain.
The results highlight the importance of discussing antidepressant side effects and adherence with individuals taking antidepressants.
The study was an observational cohort study conducted over a two-year period. Researchers included 183,118 participants in their analysis and looked at the use of eight common antidepressants.
They used prescription data from electronic medical records to gather information, focusing specifically on people who were new to antidepressants and only included participants who had been prescribed one type of antidepressant.
The average age of participants was 48. The researchers included participants who had no history of antidepressant use and were between the ages of 20 and 80. They excluded participants who had recently had cancer, were pregnant, or had bariatric surgery.
The researchers looked at weight measurements at baseline and six months, one year, and two years after starting antidepressants.
The primary outcome was to compare weight change after six months of antidepressant use with sertraline, a very commonly prescribed antidepressant. The researchers also looked at weight change at the one and two year points and estimated the likelihood that participants would gain at least 5% of their baseline weight.
Analyses allowed us to adjust for covariates such as weight change, smoking status, and medication prescriptions that may also affect evidence of recent weight change.
The study found that the most commonly used medications among participants were sertraline (Zoloft), citalopram (Celexa), and bupropion. Adherence to antidepressants was 28% to 41% at six months, but decreased to 4% to 5% after two years.
The researchers found that bupropion was associated with less weight gain than sertraline at 6 months, based on estimates. In contrast, escitalopram, duloxetine, paroxetine, venlafaxine (Effexor), and citalopram were associated with more weight gain. Fluoxetine (Prozac) was similar to sertraline with regard to this side effect.
The researchers also estimated that escitalopram, paroxetine, and duloxetine were each associated with a 10% to 15% higher risk of gaining 5% or more from baseline body weight.
Bupropion reduced the risk of gaining 5% or more of baseline body weight by 15%.
Weight gain estimates remained lower for bupropion compared with sertraline at years 1 and 2. Escitalopram was associated with weight gain after 1 year but not after 2 years. After 2 years, duloxetine and venlafaxine were associated with less weight gain than sertraline.
However, the precision of these estimates is limited due to low rates of medication adherence.
Overall, the results highlight the possibility that weight changes may need to be considered in discussions regarding antidepressant prescribing.
Eric J. Conrad, MD, FACLPCommenting on the findings, Dr. Ian McGrath, professor of psychiatry at the University of Louisiana at New Orleans and director of the behavioral health service line at the University of New Orleans Medical Center, who was not involved in the study, said: Today’s Medical News.
He told us:
“The findings of this study confirm what we largely knew from previous clinical trials and from our many years of experience prescribing these medications. The number of study subjects is impressive – more than 183,000. I think this is a good reminder to consider the possibility of weight gain when considering prescribing this group of medications, and to potentially use medications that are less likely to cause this side effect if clinically indicated and in the best choice for the patient.”
However, this study has several limitations that may have influenced the findings. First, the researchers lacked certain data that may have influenced the results. For example, there was no data on medication dispensing.
Participants’ adherence to medication was also low. The study authors also noted that data on medication adherence and weight measurements were incomplete across time points.
The researchers acknowledged that missing data may have led to misclassification of some participants as nonadherent, and there is also a risk of residual, baseline, and time-varying confounding.
Low adherence rates and low participant numbers reduced the precision of data at later time points. The study also did not examine dose-response effects.
Additionally, because this is an observational study, it cannot prove that any particular antidepressant causes weight gain or loss.
Again, while the researchers attempted to focus on first-time users of antidepressants, it is possible that some participants were not first-time users. Approximately 80% of participants were white and 65% were female, which may affect the generalizability of the results.
Additionally, approximately 15–30% of participants accurately measured their weight at 6 months, 1 year, and 2 years, with only 40–50% measuring their weight at one or more time points.
This may have influenced the results of the study. Finally, some participants were prescribed additional antidepressants during the follow-up period, which may have influenced the results.
Aarohee Desai-Gupta, MBBS, MRCPsychConsultant psychiatrist and clinical director of Atrom MindCare Holistic Psychiatry Clinic, who was not involved in the study, expressed the opinion that “the direct clinical implications based on this study alone are minimal.”
“However,” she pointed out, “if an individual patient experiences weight gain on an SSRI, [serotonin reuptake inhibitor]”With the results of this study in mind, people should consider adapting their treatment to suit their individual circumstances and requirements.”
Antidepressant groups include selective serotonin reuptake inhibitors (SSRIs), serotonin/norepinephrine reuptake inhibitors (SNRIs), and tricyclic antidepressants (TCAs).
Alex Dimitriou, MDThe double-board-certified psychiatrist and sleep medicine founder of Menlo Park Psychiatry & Sleep Medicine was not involved in the study but offered additional insights on antidepressants. MNT:
“The most common use of antidepressants is for depression and anxiety. These drugs can significantly boost mood and energy and reduce negative thoughts, obsessions, and rumination. Antidepressants are also thought to work by increasing levels of brain-derived neurotrophic factor (BDNF). BDNF is like a miracle grower for neurons, which can often help change old thought patterns and make you more open to new ideas and perspectives.”
The researchers behind the current study noted that weight gain is a common side effect of antidepressants.
Overall, the researchers were interested in learning more about the weight changes associated with specific antidepressants and to see how these results compare to each other, with the hope that these findings could help individuals receive better personalized care.
