Which Antidepressants Cause the Most Weight Gain?

Medically Reviewed on 7/1/2021
which antidepressants cause weight gain
Why do antidepressants cause weight gain? Learn about which ones do and don’t cause weight gain

Although gaining weight is a possible side effect of nearly all antidepressants, everyone responds to antidepressants differently. Some people may put on weight while on treatment, while others may not.

Antidepressants that can cause wait gain include: 

Both the likelihood of weight gain and the amount of possible weight gain vary from drug to drug. Appetite regulation and weight gain or loss are very complex reactions that are influenced by a wide variety of hormones, all of which may be negatively affected by antidepressants. Some antidepressants are more likely to cause weight gain than others:

  • TCAs and perhaps MAOIs may be more likely to cause weight gain than SSRIs or the newer antidepressants, with the exception of Remeron.
  • SSRIs tend to cause loss of appetite early on, sometimes due to side effects such as nausea, and others can cause weight gain with long-term use (e.g., Paxil).
  • Some antidepressants, such as Effexor and Wellbutrin, may be less likely to cause any weight gain.

Antidepressants that can cause weight gain

Monoamine oxidase inhibitors (MAOIs)

  • MAOIs affect neurotransmitters that communicate between brain cells, preventing an enzyme called monoamine oxidase from removing the neurotransmitters norepinephrine, serotonin, and dopamine from the brain. This allows these neurotransmitters to remain in the brain for a longer time, thus elevating your mood.
  • Weight gain is likely in the short term (less than 6 months) and long term (1 year or more).
  • Examples of MAOIs include Marplan (isocarboxazid), Nardil (phenelzine), and Parnate (tranylcypromine).

Tricyclic compounds (TCAs)

  • Tricyclic antidepressants (TCAs) help keep more serotonin and norepinephrine in the brain. These chemicals are made naturally by your body and are thought to affect your mood.
  • Weight gain is likely both in the short term and long term.

SSRIs other than paroxetine

  • SSRIs treat depression by increasing serotonin levels in the brain. Serotonin is one of the neurotransmitters that carry signals between the brain nerve cells. SSRIs block the reabsorption (reuptake) of serotonin into the neurons.
  • Weight gain in the short term is less likely. Long-term weight gain is possible, but evidence varies.
  • Examples include Paxil, Zoloft, Celexa, and Prozac.


Depression is a(n) __________ . See Answer

Antidepressants that may or may not cause weight gain

Antidepressants that do not cause weight gain

According to current scientific research, antidepressants that are least likely to cause weight gain are: 

  • Effexor (venlafaxine)
  • Wellbutrin (bupropion) 
  • Nefazodone (however, this is rarely used because it can cause severe liver problems)

What to do about unwanted weight gain from antidepressants

If you’re experiencing unwanted weight gain because of antidepressants:

  • Stick to a healthy diet and regular exercise program to keep your weight under control. 
  • Talk to your doctor about switching to a different antidepressant if necessary.

Why do antidepressants cause weight gain?

According to a 2015 study, weight gain that occurs with psychiatric drugs are caused by changes at the cellular level, including hormonal changes and changes in the metabolism of glucose (sugar) and lipids (fats). 

Antidepressants may have the following effects that contribute to increased body weight:

  • Stimulation of appetite (tricyclic antidepressants [TCAs]) with elevated mood
  • Increased carbohydrate cravings (TCAs)
  • Interference with central nervous system functions that regulate energy balance
  • Changes in the resting metabolic rate (TCAs, selective serotonin reuptake inhibitors [SSRIs] and monoamine oxidase inhibitors [MAOIs])
  • Genetic predisposition to weight gain
  • Counteracting the action of 5-HT2 receptors (serotonin receptors), which then increase appetite
  • Interference with the production of noradrenaline

Are there other options for treating depression?

Regardless of whether antidepressants are causing unwanted weight gain or not, it is always helpful to have multiple treatment options. 

  • When it comes to treating your depression, the best approach may be a combination of medications, psychotherapy, and lifestyle changes. 
  • Cognitive behavioral therapy (CBT) is a common, effective, and evidence-based option to treating depression
  • Transcranial magnetic stimulation (TMS) therapy is another great option to treat your depression, avoiding the weight gain factor altogether. 

It is always recommended to talk to your doctor about treatment protocol, especially when it comes to depression.

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Medically Reviewed on 7/1/2021
Weight gain and antidepressants: https://pubmed.ncbi.nlm.nih.gov/10926053/

Antidepressants and Weight Gain: https://womensmentalhealth.org/posts/antidepressants-and-weight-gain/

Antidepressant utilisation and incidence of weight gain during 10 years’ follow-up: population based cohort study: https://www.bmj.com/content/361/bmj.k1951