You can‘t tell if someone is depressed by taking blood tests or x-rays. Instead, experts in mental health have developed a system of diagnosing depression based on a checklist of signs and symptoms. This is called the DSM-IV system and was developed by the American Psychiatric Association.
According to this system, a person may have a Major Depressive Disorder if they have five symptoms most days for at least two weeks, including:
Sometimes symptoms like those above can be due to a physical illness or drugs. For example, certain medical conditions, illegal substances and legal medications can directly cause depression. In addition, someone with a bipolar disorder may experience periods of depression. For this reason if you have the symptoms of depression it is important to consult a knowledgeable medical practitioner for a proper diagnosis.
Click here to read about how Dysthymia is diagnosed.
Click here to read about how Bipolar Disorder is diagnosed.
American Psychiatric Association (1994). Diagnostic and Statistical Manual of Disorders (DSM-IV) Washington, American Psychiatric Association.