The term clinical depression — also called major depression — refers to a mental disorder that requires antidepressant medication, psychotherapy, or both. People with this form of depression don’t just feel sad and hopeless; rather, they have a constellation of both mental and physical symptoms that interfere with their lives.

In addition to feeling sad, they often experience guilt. Some don’t actually identify their feelings of guilt, but do admit to feeling that they’re letting others down.

Depressed individuals also typically lose interest in everyday activities. Oftentimes, their thinking has slowed, and they may even experience confusion and memory loss. Particularly in older adults, these symptoms make it challenging to differentiate depression from Alzheimer’s disease or other forms of dementia.

Patients with major depression sometimes may even want to harm themselves. Their emotional pain is so great that they believe the only way to escape the pain is through suicide. Others, because of religious or other beliefs, may not have suicidal thoughts but believe they would be better off dead.

Fortunately, just because someone talks about feeling suicidal does not necessarily mean that they will act on those feelings. However, if someone makes any suggestion of suicidal thinking, it needs to be taken seriously and assessed by an experienced mental health professional.

Physical symptoms that commonly occur in clinical depression include fatigue and a decrease in energy levels. This is often accompanied by insomnia and restless sleep, although some patients experience increased sleep.

Patients also typically lose their appetite and then experience weight loss. Such weight loss can raise concerns about physical illnesses as well. There are some depressed patients, however, who experience an increase in appetite and gain weight.