Before a clinician can successfully treat your depression, he or she must first accurately diagnosis you. As discussed previously, there are different kinds of depression, which respond to different types of treatments. What works for one sort of depression may not work for another, or might even prove harmful! Only by first making an accurate diagnosis can your doctor figure out what treatments are likely to help you.
Making an accurate diagnosis of depression can be a complex business. It requires your doctor to create a comprehensive and accurate picture of your current functioning by assessing your current and historical medical and psychological functioning and symptom profile.
Often, the diagnosis process starts with a visit to your primary care doctor. Your doctor may ask you simple questions about your feelings and experiences. A physical examination, medical history and laboratory tests will help to determine if your depression is related to a physiological (physical) condition. If a biological cause for the depression is eliminated, your primary care physician may prescribe an antidepressant medication or refer you for a thorough psychological evaluation by a psychiatrist, psychologist, or other mental health specialist doctor.
If you can manage it, it is often a good idea to meet with a mental health specialist before beginning a specific depression treatment such as a course of antidepressants. Immensely competent as they are, primary care doctors are ultimately generalists. They are simply not trained to differentiate between the many different presentations and causes of depression. In addition, they may not be up to date regarding the latest information on the most effective psychotherapy and medication options. As a result, primary care doctors are a good starting point, but they should not be your only resource for diagnosis and treatment.
The sort of mental health specialist you see will in part determine the way that specialist will tend to understand your depression and attempt to treat it. Most psychiatrists specialize in the use of medications to treat mental illness. Only a minority of psychiatrists are well trained as therapists these days. Psychologists specialize in offering psychotherapy for mental illness, but typically cannot prescribe medication (except in a few states). Other trained mental health professionals such as psychiatric nurses, clinical social workers, and counselors can also provide psychotherapy as well. You may find it most convenient to work with both a psychiatrist and some other sort of psychotherapist at the same time, so that you can benefit from both medication and psychotherapy treatments.
Any specialist you meet with will want to perform one or more face-to-face diagnostic interviews to get a good handle on your diagnosis. During these interviews, the clinician's goal is to learn more about your current problems and symptoms, as well as to obtain a complete history of previous symptoms, a family history, a history of significant stressful life events (psychosocial stressors), and information concerning your lifestyle, culture, social support structure, alcohol or drug use, and any suicidal thoughts or tendencies you may be experiencing. You may also be asked to answer questions designed to measure your "mental status" (e.g., the degree to which you are alert and oriented and display normal speech, attention and concentration abilities, memory functioning and problem solving skills).
The two most critical factors your clinician will use to determine whether or not you are suffering from clinical depression will be: 1) the degree to which your symptoms interfere with your daily life and functioning, and 2) how long your symptoms have lasted. In order to compare your symptoms to those of other people so as to determine your symptom severity, you may be asked to complete one or more formal standardized questionnaire tests such as the Hamilton Depression Rating Scale, the Beck Depression Inventory, the Zung Self-Rating Depression Scale, the Center for Epidemiologic Studies Depression Scale or the Geriatric Depression Scale (if you are 65 years of age or older). These questionnaires are useful for screening purposes and as research instruments, but are they are not the only source of information used to make a diagnosis.
Many times, self-report questionnaires can be found on-line. While it is fine (and even a good idea) to use such on-line tests to keep track of your depression, avoid the temptation to use the results from these instruments to diagnose yourself solely on the basis of your score. Accurate diagnosis can only come from a mental health professional after careful review of all results from a full diagnostic work-up.