Depression Diagnosis

People are advised to see their doctor if they are depressed for over two weeks, if their symptoms interfere with their daily activities, or if they have suicidal thoughts. Family or friends who exhibit symptoms of depression for over two weeks should be encouraged to see their doctor.

A diagnosis of depression is based on a person's medical history, family history, physical examination, laboratory tests, and psychological evaluation. People who are suspected of suffering from a depressive disorder are usually referred to a mental health specialist, such as a:

• Psychiatrist
  A psychiatrist is a medical doctor who specializes in the evaluation and treatment of mental disorders through a combination of psychotherapy, medication, and occasionally hospitalization.
• Psychologist
  A psychologist is a trained professional who diagnoses mental disorders using interviews, observation, and psychological testing. Treatment approaches include psychotherapy and behavior modification programs. Psychologists work with a medical doctor when a person's treatment includes medication. Psychologists usually have a doctoral degree (Ph.D. or Psy.D). Clinical psychologists typically work with people who have more severe mental disorders than counseling psychologists.
  
• Mental health counselor
  A mental health counselor is a trained and licensed professional who works with individuals and groups to promote optimal mental health and well-being. Mental health counselors are trained in a variety of therapeutic techniques and often work with other mental health specialists to provide treatment.
• Social worker
  Social workers help individuals or groups function the best way they can in their environment, deal with their relationships, and help them solve personal and family problems. Social workers often work with other mental health specialists to provide treatment.

Medical History

The first step in the diagnosis of depression is to determine if a person's symptoms are due to a medical condition or a medication side effect. Interviews and questionnaires are used to compile the following information:

• Start date of symptoms
• Frequency of symptoms
• Duration of symptoms
• Severity of symptoms
• Prior depressive symptoms, the treatment and effectiveness of the treatment
• Current and past medical conditions
• Current over-the-counter and prescription drugs, and herbs
• Current use of alcohol or illegal drugs
• Thoughts of death or suicide

Family History

The family history gathers information about any family members who have had a depressive disorder, their treatment, and the effectiveness of the treatment.

Physical examination and laboratory tests

The physical exam helps identify any medical conditions that may be causing a person's depressive symptoms. Laboratory tests may be ordered to determine if the symptoms are due to a medical condition (such as diabetes, hormone irregularities, or hypothyroidism).

The following tests may be ordered if a neurological disorder (such as a brain tumor or stroke) is suspected:

• CT scan
  A CT scan (computed tomography scan) uses X-rays to produce cross-sectional computerized images of the head.
• MRI
  Magnetic resonance imaging (MRI) uses radio waves, a magnetic field, and a computer to create images of the brain.
• EEG
  An electroencephalogram (EEG) is a graphical record of the electrical activity of the brain (brain waves).

Psychological evaluation

Standardized questionnaires, interviews, and behavior observation are used to diagnose a depressive disorder disorders and plan the appropriate treatment. Mental health professionals use the criteria listed in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). People who are suspected of having a severe form of depression or are at risk of suicide may require hospitalization.