What is depression?
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.
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. Medical experts have associated excessive weight gain with many health issues, including diabetesand heart disease. Being underweight can harm the heart, affect fertility, and cause fatigue.
People with depression may experience unexplained aches or pains, including joint or muscle pain, breast tenderness, and headaches. A person’s depression symptoms can worsen because of chronic pain. Why does depression make you feel tired? Why does depression make you feel tired? Learn more about the connection between depression and fatigue.
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. Depression may also be an independent risk factor for heart health problems. According to research published in 2015, one in five people with heart failure or coronary artery disease has depression.
Research indicates that chronic stress and depression are linked to inflammation and may change the immune system. Other research suggests that depression could be due to chronic inflammation.
People with depression are more likely to have inflammatory conditions or autoimmune disorders, such as irritable bowel syndrome (IBS), type 2 diabetes, and arthritis.
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.
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.