The Invisible Disease

In contrast to the normal emotional experiences of sadness, loss, or passing mood states, clinical depression is persistent and can interfere significantly with an individual's ability to function. There are three main types of depressive disorders: major depressive disorder, dysthymic disorder, and bipolar disorder (manic-depressive illness).

Symptoms and Types of Depression
Symptoms of depression include sad mood, loss of interest or pleasure in activities that were once enjoyed, change in appetite or weight, difficulty sleeping or oversleeping, physical slowing or agitation, energy loss, feelings of worthlessness or inappropriate guilt, difficulty thinking or concentrating, and recurrent thoughts of death or suicide. A diagnosis of major depressive disorder is made if a person has 5 or more of these symptoms and impairment in usual functioning nearly every day during the same two-week period. Major depression often begins between ages 15 to 30 but also can appear in children. Episodes typically recur.

Some people have a chronic but less severe form of depression, called dysthymic disorder, which is diagnosed when depressed mood persists for at least 2 years (1 year in children) and is accompanied by at least 2 other symptoms of depression. Many people with dysthymia develop major depressive episodes.

Episodes of depression also occur in people with bipolar disorder. In this disorder, depression alternates with mania, which is characterised by abnormally and persistently elevated mood or irritability and symptoms including overly-inflated self-esteem, decreased need for sleep, increased talkativeness, racing thoughts, distractibility, physical agitation, and excessive risk taking. Because bipolar disorder requires different treatment than major depressive disorder or dysthymia, obtaining an accurate diagnosis is extremely important.

Facts About Depression
Depression can be devastating to family relationships, friendships, and the ability to work or go to school. Many people still believe that the emotional symptoms caused by depression are "not real," and that a person should be able to shake off the symptoms. Because of these inaccurate beliefs, people with depression either may not recognise that they have a treatable disorder or may be discouraged from seeking or staying on treatment due to feelings of shame and stigma. Too often, untreated or inadequately treated depression is associated with suicide.

In situations where medication, psychotherapy, and the combination of these interventions prove ineffective, or work too slowly to relieve severe symptoms such as psychosis (e.g., hallucinations, delusional thinking) or suicidality, electroconvulsive therapy (ECT) may be considered. ECT is a highly effective treatment for severe depressive episodes. The possibility of long-lasting memory problems, although a concern in the past, has been significantly reduced with modern ECT techniques. However, the potential benefits and risks of ECT, and of available alternative interventions, should be carefully reviewed and discussed with individuals considering this treatment and, where appropriate, with family or friends.

Research Findings
Brain imaging research is revealing that in depression, neural circuits responsible for moods, thinking, sleep, appetite, and behaviour fail to function properly, and that the regulation of critical neurotransmitters is impaired.

Genetics research, including studies of twins, indicates that genes play a role in depression. Vulnerability to depression appears to result from the influence of multiple genes acting together with environmental factors.

Other research has shown that stressful life events, particularly in the form of loss such as the death of a close family member, may trigger major depression in susceptible individuals.

The hypothalamic-pituitary-adrenal (HPA) axis, the hormonal system that regulates the body's response to stress, is overactive in many people with depression. Research findings suggest that persistent over activation of this system may lay the groundwork for depression.

Studies of brain chemistry, mechanisms of action of antidepressant medications, and the cognitive distortions and disturbed interpersonal relationships commonly associated with depression, continue to inform the development of new and better treatments.

-Psychology Today