Although depression is often thought of as being an extreme state of sadness, there is a vast difference between clinical depression and sadness. Sadness is a part of being human -- a natural reaction to painful circumstances. All of us will experience sadness at some point in our lives. Depression, however, is a physical illness with many more symptoms than an unhappy mood.
The person with clinical depression finds that there is not always a logical reason for his dark feelings. Exhortations from well-meaning friends and family for him to "snap out of it" provide only frustration, for he can no more "snap out of it" than a diabetic can will his pancreas to produce more insulin.
Sadness is a transient feeling that passes as a person comes to terms with his troubles. Depression can linger for weeks, months or even years. The sad person feels bad, but continues to cope with living. A person with clinical depression may feel overwhelmed and hopeless.
To clarify the differences between normal sadness and depression, there are specific, defined criteria for the diagnosis of major depression:
A person who suffers from a major depressive disorder must either have a depressed mood or a loss of interest or pleasure in daily activities consistently for at least a two-week period. This mood must represent a change from the person's normal mood and impair his functioning in his daily life.
A depressed mood caused by substances such as drugs, alcohol, or medications is not considered a major depressive disorder, nor is one that is caused by a general medical condition.
In cases of bereavement, major depressive disorder may be at play if the symptoms persist for longer than 2 months or are characterized by marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation.
Major depressive disorder cannot be diagnosed if a person has a history of bipolar disorder (ie. manic, hypomanic or mixed episodes) or if the depressed mood is better accounted for by schizoaffective disorder and is not superimposed on schizophrenia.
This disorder is characterized by the presence of 5 or more of the following symptoms:
Depressed mood most of the day, nearly every day. An individual may express feeling sad or empty, or others may observe it (ex: appears tearful). Children and adolescents may exhibit irritability
Markedly diminished interest or pleasure in all, or most, daily activities most of the day, nearly every day
Significant weight changes (ex: a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day
Insomnia or hypersomnia (sleeping too much) nearly every day
Psychomotor agitation or retardation nearly every day
Fatigue or loss of energy nearly every day
Feelings of worthlessness or excessive or inappropriate guilt nearly every day
Indecisiveness or diminished ability to think or concentrate nearly every day
Recurrent thoughts of death, recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide
If you are still uncertain as to whether you (or a loved one) may be suffering from depression, screening tests exist that can help you determine whether seeking a professional evaluation is advised. There is a test provided on this site that is simple to use and completely confidential.
American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders, fourth edition. Washington, DC: American Psychiatric Association.