Depression and weight gain may have a bidirectional relationship, which means the status of one affects the other. However, experts do not fully understand the connection.

Several studies have suggested over the years that depression and weight gain are linked, and many indicate a bidirectional relationship. In other words, depression may lead to weight gain, and weight gain may lead to depression.

Although experts know there is a connection, it is likely a complicated and multifaceted one that they do not fully understand. This article unpacks what the current research says about depression and weight gain.

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According to a 2020 systematic review, the relationship between weight gain and depression is unclear. The authors noted that studies over the years have:

  • shown a relationship between the two conditions
  • found no agreement about the meaning of the association
  • shown inconsistency in the onset of both conditions

They shared observations from an earlier 2010 study that stated people with obesity had a 55% higher chance of developing depression in their lifetime. Conversely, people with depression were 58% more likely to develop obesity than people who did not have depression.

Still, many reputable organizations, such as the National Institute of Mental Health (NIMH), note that weight gain or weight changes are possible complications of depression. For some, weight changes may mean weight loss instead of gain.

Learn more about depression and weight gain here.

However, a 2019 study noted a bidirectional relationship between mood disorders and weight gain does not exist. The research found that in males, while a history of mood disorders had links to a higher body mass index (BMI), the opposite was not true.

This study also investigated the possible differences between males and females. It found that:

  • males showed reduced signs of depression with effective weight loss interventions
  • females showed an excessive risk of mood disorders related to BMI

Learn more about BMI and how to measure it here.

In a 2018 study, researchers noted that doctors must consider the correlation between depression and weight gain when treating a person with depression. In particular, they noted that addressing body image issues may help improve weight loss efforts and psychological concerns.

A 2017 study aimed to do this by looking at the relationship between weight loss and mood. To assess the relationship, the researchers recorded depression scores while people participated in a weight loss program.

They concluded that people with obesity who did not have clinical depression showed improved moods after losing weight. These effects lasted 3–12 months following the trial.

Learn more about obesity here.

In a 2019 study, researchers looked into the relationship between emotional eating and obesity or abdominal weight gain. Their findings supported the theory that emotional eating contributes to weight gain. However, other factors associated with depression, such as lack of sleep, can lead to increased weight gain.

The NIMH says that changes in appetite are one of several potential depression symptoms. They also note that a person may experience unexpected weight changes due to appetite changes.

As previously noted, appetite changes associated with depression can make people eat less and more than usual. While some people experience weight gain, others experience weight loss.

Learn more about appetite changes here.

Evidence suggests that many antidepressant medications may cause weight gain. In a 2019 review of 27 studies, researchers found an average 5% increase in weight among participants.

However, they also noted 7% or greater (statistically significant) weight gain in studies where people took one or more of the following:

  • quetiapine (Seroquel)
  • haloperidol (Haldol)
  • trifluoperazine (Stelazine)
  • risperidone (Risperdal)
  • aripiprazole (Abilify)
  • olanzapine (Zyprexa)
  • clozapine (Clozaril)

They noted only one medication associated with weight loss was bupropion (Wellbutrin).

Finally, they stated additional studies with longer duration times and larger sample sizes are needed to help confirm their findings.

Still, a person may likely gain some weight when taking medications to help treat their depression. If this is a concern, a person should consider speaking to a doctor about alternative medications or other ways to manage weight gain.

Learn more about antidepressants here.

Weight gain and depression may have links, but experts still do not fully understand how they affect each other. Depression may lead to weight gain, weight gain may lead to depression, and both may exacerbate the other condition.

In some cases, treatments for depression may cause weight gain as a side effect. A person may find working with a doctor to determine the best medication for their needs may help.

Alonso-Pedrero, L., et al. (2019). Effects of antidepressant and antipsychotic use on weight gain: A systematic review [Abstract]. https://onlinelibrary.wiley.com/doi/abs/10.1111/obr.12934

Blasco, B. V., et al. (2020). Obesity and depression: Its prevalence and influence as a prognostic factor: A systematic review. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7449839/

Depression. Overview. (2022). https://www.nimh.nih.gov/health/topics/depression

Fuller, N. R., et al. (2017). Examining the association between depression and obesity during a weight management programme [Abstract]. https://pubmed.ncbi.nlm.nih.gov/28801940/

Konttinen, H., et al. (2019). Depression, emotional eating and long-term weight changes: A population-based prospective study. https://ijbnpa.biomedcentral.com/articles/10.1186/s12966-019-0791-8

Sahle, B. W., et al. (2019). Association between depression, anxiety and weight change in young adults. https://bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-019-2385-z

Weinberger, N.-A., et al. (2018). The relationship between weight status and depressive symptoms in a population sample with obesity: The mediating role of appearance evaluation. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6341343/