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Depression (also known as unipolar depression or clinical depression)
is a mood disorder which often involves a loss of interest in life, or "anhedonia".
It is common to feel sad, discouraged, or "down" once in a while, but
for some people, this mood persists. When symptoms last two weeks or
more, and are so severe that they interfere with daily living, one can
be said to be suffering from depression.
Depression affects nearly 10% of the population at one time or another
in their lives; it occurs most often between the ages of 24 and 44.
About twice as many women as men report or receive treatment for
depression, though the gap is shrinking.
Causes of depression
No specific cause for depression has been identified, but there are a
number of factors believed to be involved.
- Heredity The tendency to develop depression may be inherited; there is
some evidence that this disorder may run in families.
- Brain chemicals called neurotransmitters allow electrical signals to move from the axon of one nerve cell to the neuron of another.
- A shortage of neurotransmitters impairs
Physiology: There may be changes or imbalances in
certain chemicals the brain uses to transmit information. These
neurotransmitters include chemicals such as serotonin, and many modern
antidepressants work on the assumption that an imbalance in this
chemical is a factor in depression. While it is not clear which is the
cause and which is the effect, it is known that antidepressant
medications do help alleviate the symptoms of depression. Seasonal
affective disorder (SAD) is a type of depressive disorder that occurs in
the winter when daylight hours are short. It is believed that the body's
production of melatonin, which is produced at increased levels in the
dark, plays a major part in the onset of SAD, and that many sufferers
respond well to bright light therapy, also known as phototherapy.
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- Psychological factors Low self-esteem and self-defeating or distorted
thinking are connected with depression. While it is not clear which is
the cause and which is the effect, it is known that sufferers who are
able to make corrections to their thinking patterns can show improved
mood and self-esteem. Psychological factors include the complex
development of one's personality and how one has learned to cope with
external environmental factors, such as stress.
Early experiences Events such as the death of a parent, abandonment or
rejection, neglect, chronic illness, and severe physical, psychological,
or sexual abuse can also increase the likelihood of depression later in
life. Post-traumatic stress disorder (PTSD) includes depression as one
of its major symptoms.
- Life experiences Job loss, financial difficulties, long periods of
unemployment, the loss of a spouse or other family member, or other
traumatic events may trigger depression.
Medical conditions Certain illnesses including hepatitis or
mononucleosis may contribute to depression, as may certain prescription
drugs such as birth control pills and steroids.
- Alcohol and other drugs Alcohol can have a negative effect on mood, and
misuse or abuse of alcohol, benzodiazepine-based tranquillizers and
sleeping medications, or narcotics can all play a major role in the
length and severity of depression.
- Post-partum depression About ten percent of new mothers experience some
form of depression after childbirth. When it occurs, the onset is
typically within three months after delivery, and it may last for
several months. About two new mothers out of a thousand have depression
so severe it includes hallucinations or delusions.
- Living with a depressed person Those living with someone suffering from
depression experience increased stress, anxiety, and life disruption,
which increases the possibility of their also becoming depressed.
- BioMechanical-Neurological Excessive stimulation of the neuroloigical
system may lead to clinical depression. The degree and persistence of
the depression is directly related to the degree and persistence of the
stimulation. This neurological reflex is part of the bodies natural
defenses,that have evolved through evolution,to protect itself from
harm. Over work,physically or mentally, may over stimulate the
neurological system which reflexively responds by creating a sense of
tiredness mentally and physically-the desire to do anything is much
Signs and symptoms
According to the DSM-IV-TR (p. 356), the two principal or required
elements of depression are:
- depressed mood, or
- loss of interest or pleasure.
It is sufficient to have either of these symptoms in conjunction with
four of a list of other symptoms. The diagnosis does not require "loss
of interest in life, anhedonia". Likewise, "lack of energy and
motivation" is not at all a required symptom of major depression.
In adults, symptoms accompanying depression often include:
- feelings of overwhelming sadness, or complete lack of emotion
- marked decrease in interest in pleasurable activities
- changing appetite and marked weight gain or weight loss
- disturbed sleep patterns, either insomnia or sleeping more than normal
- changes in activity levels, restless or moving significantly slower than
- fatigue, both mental and physical
- feelings of guilt, helplessness, anxiety, and/or fear
- lowered self-esteem
- decreased ability to concentrate or make decisions
- thinking about death or suicide
- drug or alcohol use.
Depression in children is not as evident as it is in adults; symptoms
children demonstrate include
- loss of appetite
- sleep problems such as nightmares
- problems with behavior or grades at school where none existed before
- significant behavioral changes; becoming withdrawn, sulky, aggressive
- In older children and adolescents, an additional indicator may be the
use of drugs or alcohol.
Most people who have not experienced clinical depression do not properly
understand its emotional impact, interpreting it instead as being
similar to "having the blues" or "feeling down". As the list of symptoms
above indicates, clinical depression is a syndrome of interlocking
symptoms which goes far beyond sad or painful feelings. A variety of
biological indicators, including measurement of neurotransmitter levels,
have shown that there are significant changes in brain chemistry and an
overall reduction in brain activity. One consequence of a lack of
understanding of its nature is that depressed individuals are often
criticized by themselves and others for not making an effort to help
themselves. However, the more severe the depression is, the more the
depression may take on an autonomous nature, responding neither to
positive events nor to the person's own efforts to feel better. Because
of its intractable nature, it is imperative that the depressed
individual seek professional help. Untreated depression is typically
characterized by progressively worsening episodes separated by plateaus
of temporary stability or remission, and often leads to suicide.
Types of major depression
Major depression is also referred to as major depressive disorder or
biochemical, clinical, endogenous, or biological depression. It is
characterized by a severely depressed mood that persists for at least
two weeks. Episodes of depression may start suddenly or slowly and can
occur several times though a person's life.
Clinicians recognise several subtypes of major depression.
- Melancholia is very severe, and includes a number of major physical
symptoms including sleep and appetite disturbances, weight loss, and
withdrawal. The name derives from 'black bile', one of the imagined
'four humours' postulated by Hippocrates.
- Psychotic depression is similar to melancholia, and is accompanied by
hallucinations or delusions.
- Atypical depression is characterized by anxiety and panic attacks.
- Chronic dysthymic disorder is a long-term, mild depression that lasts
for at least two years. It often begins in adolescence and spans several
Major depression may also be referred to as unipolar affective disorder.
Bipolar disorder, sometimes called manic depression, is a cyclical
illness in which moods fluctuate between extreme happiness or giddiness
and frantic activity (the manic stage) and profound depression.
Treatment of depression varies broadly, and is different for each
individual. Various types and combinations of treatments may have to be
tried. There are two primary modes of treatment, typically employed in
conjunction with one another, medication and psychotherapy. A third
treatment, electroconvulsive therapy (ECT) may be used where chemical
treatment fails. Other alternative treatments used for depression
include exercise, and the use of vitamins, herbs, or other nutritional
The effectiveness of treatment often depends on factors such as the
amount of optimism and hope the sufferer is able to maintain, the
control s/he has over stressors, the severity of symptoms, the amount of
time the sufferer has been depressed, the results of previous
treatments, and the degree of support of family, friends, and
Medication which effectively ameliorates the symptoms of depression has
been available for several decades.
Tricyclic antidepressants are the oldest, and include such medications
as amitryptyline and desipramine. They are used less commonly now, due
to side-effects which may include increased heart rate, drowsiness, and
Monoamine oxidase inhibitors (MAOIs) may be used if other antidepressant
medications are ineffective. Because there are undesirable interactions
between this class of medication and certain foods and drugs, it is
important that the user be aware of which ones to avoid. A new MAOI has
recently been introduced. Moclobemide (Manerix), known as a reversible
inhibitor of monoamine oxidase A (RIMA), follows a very specific
chemical pathway and does not require a special diet.
Selective serotonin reuptake inhibitors (SSRIs) comprise the current
standard family of antidepressants. It is thought that one cause of
depression is that an inadequate amount of serotonin, a chemical which
the brain uses to transmit signals between nerve cells, is produced.
These drugs work by preventing the reabsorption of serotonin by the
nerve cell, thus maintaining the levels the brain needs to function
effectively. This family of drugs includes fluoxetine (Prozac),
paroxetine (Paxil), and nefazodone (Serzone). These antidepressants
typically have fewer adverse side effects than the tricyclics or the
MAOIs, though such effects as drowsiness, dry mouth, and decreased
ability to function sexually may occur.
Some antidepressants have been found to work more effectively in some
patients when used in combination with another drug. Such "augmentor"
drugs include tryptophan (Tryptan) and buspirone (Buspar).
Tranquillizers and sedatives, typically the benzodiazepines, may be
prescribed to ease anxiety and promote sleep. Because of their high
potential for addiction, these medications are intended only for
short-term or occasional use. Medications are often employed not for
their primary function, but to exploit what are normally side effects.
Quetiapine fumarate (Seroquel) is designed primarily to treat
schizophrenia and bipolar disorder, but a frequently-reported
side-effect is somnolence. Hence, this non-addictive drug can be used in
place of an addictive anti-anxiety agent such as clonazepam (Klonopin,
Antipsychotics such as risperidone (Risperdal) and olanzapine (Zyprexa)
are prescribed as mood stabilizers and are also effective in treating
anxiety. However, they may have serious side effects, particularly at
high doses, which may include blurred vision, muscle spasms,
restlessness, tardive dyskinesia, and weight gain.
Lithium remains the standard treatment for bipolar disorder, but may
also be effective for people with depression, particularly in preventing
relapse. Lithium's potential side effects include thirst, tremors,
light-headedness, and nausea or diarrhea.
Failure to take medication, or failure to take it as prescribed, is one
of the major causes of relapse. Should one feel a change or
discontinuation of medication is necessary, it is critical that this be
done in consultation with a doctor.
In psychotherapy, or counselling, one receives assistance in
understanding and resolving problems which may be contributing to
depression. This may be done individually or with a group, and is
conducted by health professionals such as psychiatrists, psychologists,
social workers, or psychiatric nurses. It is important to enquire about
both the therapist's training and approach; a very close bond often
forms between practitioner and client, and it is important that the
client feel understood by the clinician.
Counsellors can help a person make changes in thinking patterns, deal
with relationship issues, detect and deal with relapses, and understand
the factors that contribute to depression.
There are many therapeutic approaches, but all are aimed at improving an
individual's personal and interpersonal functioning. Cognitive therapy
focuses on how people think about themselves and their relationship to
the world. It works to counteract negative thought patterns and enhance
self-esteem. Therapy can be used to help a person develop or improve
interpersonal skills in order to allow them to communicate more
effectively and reduce stress. Behavioral therapy is based on the
assumption that behaviors are learned. This type of therapy attempts to
teach individuals new and healthier types of behaviors. Supportive
therapy encourages people to discuss their problems and provides them
with emotional support. The focus is on sharing information, ideas, and
strategies for coping with daily life. Family therapy helps people live
together more harmoniously and undo patterns of destructive behavior.
Electroconvulsive therapy, also known as electroshock therapy, shock
therapy, or ECT employs a small and carefully controlled current of
electricity to induce an artificial epileptic seizure while the patient
is under general anesthesia. This therapy may be employed where other
means of treatment have failed, or where the use of drugs is
unacceptable, such as in pregnancy. In a typical regimen of treatment, a
patient receives three treatments per week over three or four weeks.
Repeat sessions may be required. Short-term memory loss or headache may
result from this treatment.
Transcranial Magnetic Stimulation
Repetitive Transcranial Magnetic Stimulation (rTMS) is currently under
study as a possible treatment for depression. Initially designed as a
tool for physiological studies of the brain, this technique shows
promise as a means of alleviating depression. In this therapy, a
powerful magnetic field is used to stimulate the left prefrontal cortex,
an area of the brain which typically shows abnormal activity in
depressed individuals. Studies currently show an efficacy similar to
that of ECT, but with fewer side effects. No sedation is required, and
the only reported side effects are a slight headache in some patients,
and facial muscle contraction during treatment.