Diagnosis then becomes a matter of placing a patient on this scale to determine which type of treatment will be most useful.
Psychologists use the Diagnostic and Statistical Manual of Mental Disorders along with several accepted written tests, or surveys to diagnose depression in their patients.
But one of the main tools is still simply having a meaningful conversation with their patient.
One critical factor is to eliminate what are called somatic symptoms – these are black moods due to an underlying illness or medical condition. If a physical cause is found, the expectation is that alleviating this illness will also cure the depression.
After physical causes are eliminated through a medical exam, a medical history and any relevant lab tests, the diagnosis proceeds by scoring a patient on a scale of depression symptoms. These are:
- How often feelings of sadness, hopelessness, and depressed mood occur – every day, almost every day, weekly and so on.
- Does the patient still find enjoyment in some areas of their life?
- Are there sleep pattern disturbances or restless thoughts that disturb sleep?
- Does the patient experience unexplained fatigue and an inability to accomplish daily tasks?
- Has mental acuity suffered?
- Has the patient contemplated suicide?
- Have others mentioned symptoms?
Symptoms are what the patient reports. Signs are what the doctor observes. Some signs of depression are:
- Lack of eye contact or excessive glancing away.
- Anger or defiance in a man or adolescent, self deprecation in others.
- Preoccupation – an inability to appropriately “switch gears”
- Slow reaction times, lack of expressive movements and facial expressions
- Signs of agitation – repetitive motions like hand wringing or hair pulling
- Obvious signs of emotional distress – especially sadness or anxiety. Inappropriate weeping or expressions of despair.
- Dependency and an inability to make decisions or plans
- Inability to talk about future plans and goals optimistically.
A survey in this sense is a test used by doctors to score a patient on a depression index. This is not definitive, but adds support to a diagnosis. There are many such surveys, and a doctor may have a particular one she prefers. They all ask questions about feelings and behaviors related to depression. An example of the type of test used can be found here.