Depression is not only a mental disorder; it can affect the body physically in many ways. For example, depression is linked to a change in body weight for many sufferers. Some people lose weight when faced with severe depressive symptoms, while others gain weight.
The Definition of Depression
According to the Merck Manual, depression is a feeling of sadness that is intense enough to interfere with normal, everyday functioning. It is the second most common mental health disorder after anxiety and affects about 30% of the population. There are a number of factors that can make depression more likely to occur, including family tendency, genetic abnormalities, hormonal influences, abnormal thyroid function, and sex (women are twice as likely than men to experience depression).
Depression and Weight Loss
For some, depression symptoms can lead to a decrease in appetite. Those who suffer from melancholic depression do not find pleasure in activities that they used to enjoy. These are the patients that tend to stop eating and lose weight. They may also be more prone to abuse alcohol or other drugs, which can disrupt food intake.
Some depressed patients are also more likely to smoke heavily. Smoking is a very common cause of inflammation in the mouth and loss of the taste sensation. Nicotine also deadens the taste buds, contributes to periodontal disease, and can suppress nerve activity in the brain that is associated with taste. All of these factors can influence a decrease of food intake and a resulting weight loss.
Depression and Weight Gain
Patients with Atypical Depression are often fearful and anxious which can increase appetite resulting in weight gain. Atypical depression symptoms are often worse at night, which for many is a time when high calorie and high fat foods call to them to provide comfort.
People with depression, because they feel hopeless about their future, will often neglect their health in other ways as well, such as not exercising or taking appropriate medications for chronic conditions. Many of these factors can also lead to weight gain.
Anti-depression medications have been implicated in an increase of body fat although the relationship isn’t clear. Some mental health experts say that about 25% of patients taking anti-depressant medications can expect about a 10 pound or more weight gain.
Some medications are more apt to cause an increase in weight. These include selective serotonin reuptake inhibitors (SSRI’s) such as Prozac, Paxil, Zoloft, and Lexapro and monoamine oxidase inhibitors (MAOI’s) such as Parnate and Nardil.
Biologically, depression is associated with an inflammatory state that can lead to weight gain and obesity. Certain immune system hormones, called cytokines, and inflammatory markers, such as C-reactive protein, are more positively correlated with a depressive state. These can negatively influence body mass and can increase the incidence of chronic health conditions such as diabetes and heart disease which can make weight loss more difficult.
The Bottom Line
Any change in mood that lasts longer than two weeks or is associated with health conditions such as weight loss or weight gain should be discussed with your physician. In addition, for those with a weight gain related to depression, exercise can lift your mood and help to reduce or maintain weight.