How does depression affect the body?
What is depression?
Depression often causes a person to feel sad and hopeless.
Depression is a complex mental health condition that causes a person to have low mood and may leave them feeling persistently sad or hopeless.
Depressive symptoms can be a temporary experience in response to grief or trauma. But when the symptoms last longer than 2 weeks, it can be a sign of a serious depressive disorder.
The same symptoms can also be a sign of another mental health condition, such as bipolar or post-traumatic stress disorder (PTSD).
The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) lists the following symptoms of depression:
- depressed mood on most days, including feelings of sadness or emptiness
- loss of pleasure in previously enjoyed activities
- too little or too much sleep most days
- unintended weight loss or gain or changes in appetite
- physical agitation or feelings of sluggishness
- low energy or fatigue
- feeling worthless or guilty
- trouble concentrating or making decisions
- intrusive thoughts of death or suicide
The symptoms vary between individuals and may change over time. For a doctor to diagnose depression, a person must have five or more symptoms that must be present during the same 2-week period.
Image credit: Stephen Kelly, 2018
Physical symptoms of depression
Research has documented many ways that depression can affect physical health, including the following:
Weight gain or loss
People with depression may experience appetite changes, which can cause unintended weight loss or gain.
A person's depression symptoms can worsen because of chronic pain.
Depression can reduce a person's motivation to make positive lifestyle choices. Their risk of heart disease increases when they eat a poor diet and have a sedentary lifestyle.
Stay in the know. Get our free daily newsletter
You’ve got questions. We’ve got answers. Expert, evidence-based advice delivered straight to your inbox to help you take control of your healthYour privacy is important to us.
However, it is unclear whether depression causes inflammation or chronic inflammation makes someone more vulnerable to depression. More research is necessary to understand the link between the two.
Sexual health problems
People with depression may have a decreased libido, have trouble becoming aroused, no longer have orgasms, or have less pleasurable orgasms.
Some people also experience relationship problems due to depression, which can have an impact on sexual activity.
Worsening chronic health conditions
People who already have a chronic health condition may find their symptoms are worse if they develop depression.
Chronic illnesses may already feel isolating or stressful, and depression may exacerbate these feelings.
A person with depression may also struggle to follow the treatment plan for a chronic illness, which can allow the symptoms to get worse.
People who experience depression and who have a chronic illness should talk to a doctor about strategies for addressing both conditions. Preserving mental health may improve physical health and make a chronic condition easier to manage.
Depression may contribute to insomnia.
People with depression may experience insomnia or trouble sleeping.
This condition can leave them feeling exhausted, making it difficult to manage both physical and mental health.
Doctors link sleep deprivation to a host of health problems. Similarly, research has correlated long-term sleep deprivation with high blood pressure, diabetes, weight-related issues, and some types of cancer.
According to research published in 2016, this may be because depression changes the brain's response to stress by suppressing activity in the hypothalamus, pituitary gland, and adrenal glands.
Recognizing that depression can cause physical health problems can help a person to seek treatment and make changes to help manage their symptoms.
Depression is treatable. A doctor may recommend a combined approach, using medication, therapy, and lifestyle changes. With the right support, a person can manage both physical and mental health effects of depression.