Sometimes, symptoms that look like depression aren’t really depression, however. Substance abuse issues, medical problems, medication side effects, or other mental health conditions may produce symptoms that look similar to depression.
A person with a depressed mood may report feeling “sad” or “empty,” or may cry frequently. In major depression, an individual must feel depressed most of the day, nearly every day, as indicated by either subjective report or observations made by others. Children or adolescents may appear more irritable than sad.
The second core symptom of major depressive disorder is a decreased interest or pleasure in things that were once enjoyed. A person exhibiting this symptom will show markedly diminished interest or pleasure in all, or almost all, daily activities.
Significant changes in weight (a gain or loss of 5 percent or more in a month) while not attempting to gain or lose may be indicative of major depressive disorder. In children, this may also present as a failure to make expected weight gains.
Persistent depressive disorder may involve a poor appetite or overeating but there may not be the same marked change in weight that is present in major depressive disorder.
Sleep disturbances including difficulty falling asleep, staying asleep, feeling sleepy despite a full night’s rest, or daytime sleepiness can indicate either major depressive disorder or persistent depressive disorder.
Agitation, restlessness, or lethargy that affects a person’s daily routine, behavior or appearance is a symptom of major depressive disorder These symptoms can be evident in body movements, speech, and reaction time and must be observable by others.
A loss of energy and chronic feelings of fatigue can be symptoms of both persistent depressive disorder and major depressive disorder. Feeling tired most of the time can interfere with an individual’s ability to function normally.
Excessive, inappropriate guilt, and feelings of worthlessness are common symptoms of major depressive disorder. The feelings of guilt may be so severe they become delusional.
Both major depressive disorder and persistent depressive disorder involve difficulty concentrating and making decisions. Individuals with depression may recognize this in themselves or others around them may notice that they’re struggling to think clearly.
Recurrent thoughts of death that go beyond the fear of dying are associated with major depressive disorder. An individual with major depression may think about suicide, make a suicide attempt, or create a specific plan to kill themselves.