Depression is usually treated with either
medication or psychotherapy, or both. Often,
from a biological perspective, the causes
of psychiatric disorders are called "chemical
imbalances" because it is believed
that abnormal amounts or functions of chemicals
in the brain produce the symptoms and changes
in behavior usually observed. The sources
of these imbalances can be either genetic
or environmental. It is likely that in most
cases, the causes are multiple, including
both genes and situational changes. For
example, especially for depressed individuals
who have several blood relatives with depression,
genes are likely to be playing an important
role in the source of the depression and
even in the types of medications most likely
to be beneficial. Other factors, such as
stress-related environmental effects and
learned changes in thought and behavior,
are very frequently involved. Accumulating
evidence indicates not only that genes can
affect environmental responses, but also
that environmental factors and behaviors
can modulate gene action.
The chemicals present in the brain that
control its functions (thoughts, emotions,
motivations, normal and abnormal behaviors)
are called
. There are a wide variety of these chemicals
in the brain, and more are being discovered
every year. Two of the earliest discovered
and most important are
and
. These various substances are called neurotransmitters
because they exist in neural tissue (brain
and the rest of the nervous system) and
transmit information between the nerve cells
(called neurons). Information is passed
in specialized regions between the cells
called synapses when one neuron stimulates
(or inhibits) the firing of another neuron.
This occurs when the first neuron releases
neurotransmitter molecules, that in turn
affect the second neuron. The effect of
the neurotransmitter chemical on the second
neuron occurs at specialized areas on the
neuron called receptors.
One important early theory of the biological
cause of depression suggested that there
was too little serotonin, and/or too little
norepinephrine, in the brains of depressed
people. This theory originated in part from
the discovery that all drugs that relieved
depression increased the effects of serotonin
or norepinephrine. In the brain, the effects
of both serotonin and norepinephrine are
turned off by
of the neurotransmitter molecules from the
into the first neuron, therefore stopping
the effect on the second neuron. (For the
system to work properly, it must turn on
and turn off properly.) The primary mechanism
by which drugs that treat depression work,
is by decreasing the reuptake into the first
neuron, leaving more to affect the second
neuron. By the theory, this would relieve
the effects of too little serotonin and/or
norepinephrine. That is why many antidepressant
drugs are called "reuptake inhibitors"
(for example, why drugs like fluoxetine-Prozac-are
often called "SSRIs"-Selective/Specific
Serotonin Reuptake Inhibitors). More recent
theories suggest more complex mechanisms
for how these drugs relieve depression (and
why they take weeks to do so), but reuptake
blockade undoubtedly plays a role.
How well do antidepressants work in practice?
They are used mainly for moderate or severe
depressive symptoms. They can be used in
combination with psychotherapy, which is
often most effective. They typically take
1-3 weeks to have any benefit, and 1-3 months
for full benefit. One-half to two-thirds
of patients who are correctly diagnosed
with major depressive disorder will respond
to the first drug chosen, and 75% to 80%
of patients will eventually respond if several
different medications are given full trials.
Overall, no type of antidepressant drug
is more effective than any other, but the
different types can have different side
effects, and different drugs sometimes are
more or less effective for different individuals.
Many patients will have more than one disorder
(co-morbidity). These individuals sometimes
need additional treatment. Patients are
more prone to relapse if they discontinue
treatment before it is recommended (usually
at least 4-6 months). The more severe the
depression (more severe symptoms, longer
duration of symptoms, prior episodes of
depression earlier in their lives, many
blood relatives with the same disorder,
co-morbid disorders such as substance abuse,
anxiety, personality disorder) the longer
treatment should last, even up to life-long.
The major causes of lack of treatment response
include inadequate medication dose or length
of treatment, wrong
, and patient non-adherence to treatment
recommendations.
Treatments other than medications are available
for depression. These include various methods
of counseling and psychotherapy, so-called
non-traditional treatment methods (such
as herbal substances), and in more severe
cases such methods as E.C.T. Placebos (substances
or methods not known to have specific effects)
produce improvement in about one-third of
patients.
There are many sources of information about
depression for patients and other interested
individuals. Whether it is a book, a computer
source, or advice of a friend, be open-minded
but critical of the source and the information
at the same time. Depression is a very common,
and often quite debilitating illness, so
there is a great deal of interest in the
topic, but not always sufficient quality
control for the claims made.
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