Depression is a whole-body
illness which causes changes far beyond sadness. Many people with depression
do not even feel sad; instead they may feel emptiness or anger or have no
ability to experience pleasure (called anhedonia). Sometimes
depression expresses itself through fatigue or physical symptoms rather than
Along with this change in mood,
depression causes important changes in the brain and body. These can include
poor sleep, fatigue, slowed thoughts, poor concentration, lack of appetite or
excessive eating, and low sex drive. The muscles may become lax and slowed,
or tense and agitated. The immune system, which protects the body from
infection, may not work as well and stress hormones may increase. If left untreated,
depression can take a toll on a person’s health, with consequences such as
heart disease and changes in the brain’s memory center.
There are many causes of
depression. The most common is Major Depressive Disorder, which is best
treated with antidepressants and psychotherapy. Depression can also be caused by a medical
illness or the effects of drugs or alcohol, and require different
treatment. In bipolar disorder, depression
is one phase of an underlying problem with mood swings.
Depression can be distinguished
by its cause as well as by its form.
There are many different forms of depression, including:
Here the depression is distinctly different from ordinary sadness; it may
be experienced as a profoundly empty, bleak, dark and unmotivated state. This mood rarely changes or reacts to life,
but may be worse in the morning. This
depression causes the mind to ruminate along themes of guilt or worry. The body is also uniquely affected, with
awakening early in the morning and muscles that are either slowed or
This depression is actually very common, but was called atypical because when
it was first discovered in the 1950’s it was thought to be a rare form. Atypical depression causes a uniquely reactive mood: it may overreact to
stress or change randomly throughout the day. Fatigue, oversleeping, and
overeating (especially sweets and carbohydrates) are very common. This depression tends to affect the muscles
as well, making people feel heavy or weighed down (called leaden paralysis). Atypical depression
is important to recognize because it often returns in cycles and may have
seasonal patterns. Atypical depression
is the most common type of depression in bipolar disorder, but
having atypical depression does not mean that you have bipolar.
Dysthymia or Dysthymic Disorder
This refers to a chronic, low-grade depression that persists for at least two
years (and usually throughout life).
Although the depression is “low-grade”, its persistence can affect
people as profoundly as a severe depression.
People with dysthymia experience little
pleasure in life and may tend to isolate from others. On the other hand, the condition may
strengthen their ability to shoulder life’s burdens: people with dysthymia often have very good work-ethics. It is
described in more detail in the section on temperament.
To continue on to the next section,
—Updated 8/5/11 by Chris Aiken, MD