Depression

Depression

Type of psychology: Psychopathology
Field of study: Depression
The study of depression has focused on biological underpinnings, cognitive concomitants,
stress and coping style precursors, and interpersonal context.

Key concepts

• bipolar disorder
• major depressive episode
• manic episode
• unipolar depression

Almost everyone gets “down in the dumps” or has “the blues” sometimes.
Feeling sad or dejected is clearly a normal part of the spectrum of human
emotion. This situation is so common that a very important issue is how to
separate a normal blue or down mood or emotion from an abnormal clinical
state. Most clinicians use measures of intensity, severity, and duration of
these emotions to separate the almost unavoidable human experience of
sadness and dejection from clinical depression.

Depression is seen in all social classes, races, and ethnic groups. It is so
pervasive that it has been called the common cold of mental illness in the
popular press. It is approximately twice as common among women as it is
among men. Depression is seen among all occupations, but it is most common
among people in the arts and humanities. Famous individuals such as
American president Abraham Lincoln and British prime minister Winston
Churchill had to cope with depression; Churchill called the affliction “the
black dog.” More recently, United States senator Thomas Eagleton and astronaut
Edwin “Buzz” Aldrin were known to have bouts of serious depression.
Of all problems that are mentioned by patients at psychological and psychiatric
clinics, some form of depression is most common. It is estimated
that approximately 25 percent of women in the United States will experience
at least one significant depression during their lives. Contrary to a popular
misconception that depression is most common among the elderly, it is
actually most common in twenty-five- to forty-four-year-olds. About 10 percent
of the college population report moderate depression, and 5 percent
report severe depression. Suicidal thoughts are common in depressive clients.
In long-term follow-up, it has been found that approximately 15 percent
of depressed individuals eventually kill themselves. Alternatively
viewed, approximately 60 percent of suicides are believed to be caused by
depression or by depression in association with alcohol abuse. As has been
vividly portrayed in the media, teenage suicide in the United States is increasing
at an alarming rate.

The role of family or genetic factors in depression was addressed long ago by Robert Burton in The Anatomy of Melancholy (1621), in which he noted
that the “inbred cause of melancholy is our temperature, in whole or part,
which we receive from our parents” and “such as the temperature of the father
is, such is the son’s, and look what disease the father had when he begot
him, his son will have after him.” More than 350 years later, the role of family
factors in depression was addressed in a major collaborative study in the
United States. In what was called the National Institute of Mental Health
Collaborative Study of the Psychobiology of Depression, a large number of
standardized instruments were developed to assess prevalence and incidence
of depression, life histories, psychosocial stressors, and outcome of
depression. The family members of depressed persons were assessed along
with the depressed individual. It was found that bipolar depression was
largely confined to relatives of individuals with bipolar disorder. Unipolar
depression, however, was common among relatives of both unipolar- and
bipolar-depressed individuals. The different patterns of familial transmission
for bipolar and unipolar disorders strengthen the general conviction
that these two disorders should be kept distinct from each other.

One explanation for increased vulnerability to depression in close relatives
of depressed individuals is an inherited deficiency in two key components of brain chemistry: norepinephrine and serotonin, both of which are
neurotransmitters. If depressions could be reliably subtyped according to
the primary neurotransmitter deficiency, the choice of antidepressant medication
would logically follow. Research is conflicting, however, on whether
there is one group of depressed individuals who are low in norepinephrine
and normal in serotonin and another group of depressives who are low in serotonin
and normal in norepinephrine. Future developments in the study
of neurotransmitters may have practical implications for the matching of
particular pharmacotherapy interventions with particular types of depression.
Evidence does indicate that for many depressed patients, substantial
alteration in neurotransmitter activity occurs during their depression. This
altered activity may directly mediate many of the disturbing symptoms of depression.