At Eternity’s Gate

Major depressive disorder

- a.k.a. clinical depression, major depression, unipolar depression, or unipolar disorder

A mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and loss of interest or pleasure in normally enjoyable activities. The term "major depressive disorder" was selected by American Psychiatric Association to designate this symptom cluster as a mood disorder in the 1980 version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), and has become widely used since. The general term depression is often used to denote the disorder, but as it can also be used in reference to other types of psychological depression, more precise terminology is preferred for the disorder in clinical and research use. Major depression is a disabling condition which adversely affects a person's family, work or school life, sleeping and eating habits, and general health. In the United States, approximately 3.4% of people with major depression commit suicide, and up to 60% of people who commit suicide have depression or another mood disorder.

The diagnosis of major depressive disorder is based on the patient's self-reported experiences, behavior reported by relatives or friends, and a mental status exam. There is no laboratory test for major depression, although physicians generally request tests for physical conditions that may cause similar symptoms. The most common time of onset is between the ages of 20 and 30 years, with a later peak between 30 and 40 years. Major depression is reported about twice as frequently in women as in men, and women attempt suicide more often, although men are at higher risk for completing suicide.

Most patients are treated in the community with antidepressant medication and some with psychotherapy or counselling. Hospitalization may be necessary in cases with associated self-neglect or a significant risk of harm to self or, rarely, others. A minority are treated with electroconvulsive therapy (ECT), under a short-acting general anaesthetic. The course of the disorder varies widely, from one episode lasting months to a lifelong disorder with recurrent major depressive episodes. Depressed individuals have shorter life expectancies than those without depression, in part because of greater susceptibility to medical illnesses and suicide. Current and former patients may be stigmatized.

The understanding of the nature and causes of depression has evolved over the centuries, though this understanding is incomplete and many aspects of depression are still the subject of discussion and research. Proposed causes include psychological, psycho-social, hereditary, evolutionary and biological factors. Psychological treatments are based on theories of personality, interpersonal communication, and learning. Most biological theories focus on the monoamine chemicals serotonin, norepinephrine and dopamine, which are naturally present in the brain and assist communication between nerve cells. Monoamines have been implicated in depression, and most antidepressants work to increase the active levels of at least one.

DSM-III (1980)

In 1974, the decision to create a new revision of the DSM was made, and Robert Spitzer was selected as chairman of the task force. The initial impetus was to make the DSM nomenclature consistent with the International Statistical Classification of Diseases and Related Health Problems (ICD), published by the World Health Organization. The revision took on a far wider mandate under the influence and control of Spitzer and his chosen committee members. One goal was to improve the uniformity and validity of psychiatric diagnosis in the wake of a number of critiques, including the famous Rosenhan experiment. There was also a need to standardize diagnostic practices within the US and with other countries after research showed that psychiatric diagnoses differed markedly between Europe and the USA. The establishment of these criteria was also an attempt to facilitate the pharmaceutical regulatory process.

The criteria adopted for many of the mental disorders were taken from the Research Diagnostic Criteria (RDC) and Feighner Criteria, which had just been developed by a group of research-orientated psychiatrists based primarily at Washington University in St. Louis and the New York State Psychiatric Institute. Other criteria, and potential new categories of disorder, were established by consensus during meetings of the committee, as chaired by Spitzer. A key aim was to base categorization on colloquial English descriptive language (which would be easier to use by Federal administrative offices), rather than assumptions of etiology, although its categorical approach assumed each particular pattern of symptoms in a category reflected a particular underlying pathology (an approach described as "neo-Kraepelinian”). The psychodynamic or physiologic view was abandoned, in favor of a regulatory or legislative model. A new "multiaxial" system attempted to yield a picture more amenable to a statistical population census, rather than just a simple diagnosis. Spitzer argued, “mental disorders are a subset of medical disorders” but the task force decided on the DSM statement: “Each of the mental disorders is conceptualized as a clinically significant behavioral or psychological syndrome.”

The first draft of the DSM-III was prepared within a year. Many new categories of disorder were introduced; a number of the unpublished documents that aim to justify them have recently come to light. Field trials sponsored by the U.S. National Institute of Mental Health (NIMH) were conducted between 1977 and 1979 to test the reliability of the new diagnoses. A controversy emerged regarding deletion of the concept of neurosis, a mainstream of psychoanalytic theory and therapy but seen as vague and unscientific by the DSM task force. Faced with enormous political opposition, so the DSM-III was in serious danger of not being approved by the APA Board of Trustees unless “neurosis” was included in some capacity, a political compromise reinserted the term in parentheses after the word “disorder” in some cases. Additionally, the diagnosis of ego-dystonic homosexuality replaced the DSM-II category of "sexual orientation disturbance".

Finally published in 1980, the DSM-III was 494 pages long and listed 265 diagnostic categories. It rapidly came into widespread international use by multiple stakeholders and has been termed a revolution or transformation in psychiatry.

DSM-IV (1994)

In 1994, DSM-IV was published, listing 297 disorders in 886 pages. The task force was chaired by Allen Frances. A steering committee of 27 people was introduced, including four psychologists. The steering committee created 13 work groups of 5–16 members. Each work group had approximately 20 advisers. The work groups conducted a three step process. First, each group conducted an extensive literature review of their diagnoses. Then they requested data from researchers, conducting analyses to determine which criteria required change, with instructions to be conservative. Finally, they conducted multicenter field trials relating diagnoses to clinical practice. A major change from previous versions was the inclusion of a clinical significance criterion to almost half of all the categories, which required symptoms cause “clinically significant distress or impairment in social, occupational, or other important areas of functioning”.

ADHD (Attention Deficit Hyperactivity Disorder) was characterized at this stage.

Tricyclic antidepressants

Tricyclic antidepressants (TCAs) are heterocyclic chemical compounds used primarily as antidepressants. The TCAs were first discovered in the early 1950s and were subsequently introduced later in the decade. They are named after their chemical structure, which contains three rings of atoms. The tetracyclic antidepressants (TeCAs), which contain four rings of atoms, are a closely related group of antidepressant compounds.

In recent times, the TCAs have been largely replaced in clinical use in most parts of the world by newer antidepressants such as the selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), among others, though they are still sometimes prescribed for certain indications.