Download Antidepressant Medications

Antidepressant Medications
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 nonadherence 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.
What are the symptoms of major depression?
The onset of the first episode of major depression may not be obvious if it is
gradual or mild. The symptoms of major depression characteristically represent a
significant change from how a person functioned before the illness. The symptoms
of depression include:

persistently sad or irritable mood

pronounced changes in sleep, appetite, and energy

difficulty thinking, concentrating, and remembering

physical slowing or agitation

lack of interest in or pleasure from activities that were once enjoyed

feelings of guilt, worthlessness, hopelessness, and emptiness

recurrent thoughts of death or suicide

persistent physical symptoms that do not respond to treatment, such as
headaches, digestive disorders, and chronic pain
When several of these symptoms of depressive illness occur at the same time, last
longer than two weeks, and interfere with ordinary functioning, professional
treatment is needed.
What are the causes of major depression?
There is no single cause of major depression. Psychological, biological, and
environmental factors may all contribute to its development. Whatever the specific
causes of depression, scientific research has firmly established that major
depression is a biological, medical illness.
Norepinephrine, serotonin, and dopamine are three neurotransmitters (chemical
messengers that transmit electrical signals between brain cells) thought to be
involved with major depression. Scientists believe that if there is a chemical
imbalance in these neurotransmitters, then clinical states of depression result.
Antidepressant medications work by increasing the availability of neurotransmitters
or by changing the sensitivity of the receptors for these chemical messengers.
Scientists have also found evidence of a genetic predisposition to major depression.
There is an increased risk for developing depression when there is a family history
of the illness. Not everyone with a genetic predisposition develops depression, but
some people probably have a biological make-up that leaves them particularly
vulnerable to developing depression. Life events, such as the death of a loved one,
a major loss or change, chronic stress, and alcohol and drug abuse, may trigger
episodes of depression. Some illnesses such as heart disease and cancer and some
medications may also trigger depressive episodes. It is also important to note that
many depressive episodes occur spontaneously and are not triggered by a life crisis,
physical illness, or other risks.
How is major depression treated?
Although major depression can be a devastating illness, it is highly treatable.
Between 80 and 90 percent of those diagnosed with major depression can be
effectively treated and return to their usual daily activities and feelings. Many
types of treatment are available, and the type chosen depends on the individual
and the severity and patterns of his or her illness. There are three well-established
types of treatment for depression: medications, psychotherapy, and
electroconvulsive therapy (ECT). For some people who have a seasonal component
to their depression, light therapy may be useful. These treatments may be used
alone or in combination. Additionally, peer education and support can promote
recovery. Attention to lifestyle, including diet, exercise, and smoking cessation,
can result in better health, including mental health.
Medication. . It often takes two to four weeks for antidepressants to start having
an effect, and 6-12 weeks for antidepressants to have their full effect. The first
antidepressant medications were introduced in the 1950s. Research has shown that
imbalances in neurotransmitters like serotonin, dopamine, and norepinephrine can
be corrected with antidepressants. Four groups of antidepressant medications are
most often prescribed for depression:

Selective serotonin reuptake inhibitors (SSRIs) act specifically on the
neurotransmitter serotonin. They are the most common agents prescribed for
depression worldwide. These agents block the reuptake of serotonin from the
synapse to the nerve, thus artificially increasing the serotonin that is available
in the synapse (this is functional serotonin, since it can become involved in
signal transmission, the cardinal function of neurotransmitters). SSRIs include
fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa),
escitalopram (Lexapro), and fluvoxamine (Luvox).

Serotonin and norepinephrine reuptake inhibitors (SNRIs) are the secondmost popular antidepressants worldwide. These agents block the reuptake of
both serotonin and norepinephrine from the synapse into the nerve (thus
increasing the amounts of these chemicals that can participate in signal
transmission). SNRIs include venlafaxine (Effexor) and duloxetine (Cymbalta).

Bupropion (Wellbutrin) is a very popular antidepressant medication
classified as a norepinephrine-dopamine reuptake inhibitor (NDRI). It acts by
blocking the reuptake of dopamine and norepinephrine.

Mirtazapine (Remeron) works differently from the compounds discussed
above. Mirtazapine targets specific serotonin and norepinephrine receptors in
the brain, thus indirectly increasing the activity of several brain circuits.

Tricyclic antidepressants (TCAs) are older agents seldom used now as firstline treatment. They work similarly to the SNRIs, but have other neurochemical
properties which result in very high side effect rates, as compared to almost all
other antidepressants. They are sometimes used in cases where other
antidepressants have not worked. TCAs include amitriptyline (Elavil, Limbitrol),
desipramine (Norpramin), doxepin (Sinequan), imipramine (Norpramin,
Tofranil), nortriptyline (Pamelor, Aventyl), and protriptyline (Vivactil).

Monoamine oxidase inhibitors (MAOIs) are also seldom used now. They work
by inactivating enzymes in the brain which catabolize (chew up) serotonin,
norepinephrine, and dopamine from the synapse, thus increasing the levels of
these chemicals in the brain. They can sometimes be effective for people who
do not respond to other medications or who have “atypical” depression with
marked anxiety, excessive sleeping, irritability, hypochondria, or phobic
characteristics. However, they are the least safe antidepressants to use, as
they have important medication interactions and require adherence to a
particular diet. MAOIs include phenelzine (Nardil), isocarboxazid (Marplan), and
tranylcypromine sulfate (Parnate).

Non-antidepressant adjunctive agents. Often psychiatrists will combine the
antidepressants mentioned above with each other (we call this a
“combination”) or with agents which are not antidepressants themselves (we
call this “augmentation”). These latter agents can include the atypical
antipsychotic agents [aripiprazole (Abilify), olanzapine (Zyprexa), quetiapine
(Seroquel), ziprasidone (Geodon), risperidone (Risperdal)], buspirone (Buspar),
thyroid hormone (triiodothyonine, or “T3”), the stimulants [methylphenidate
(Ritalin), dextroaphetamine (Aderall)], dopamine receptor agonists
[pramipexole (Mirapex), ropinirole (Requipp)], lithium, lamotrigine (Lamictal),
s-adenosyl methionine (SAMe), pindolol, and steroid hormones (testosterone,
estrogen, DHEA).
What are the different kinds of antidepressants?
Antidepressants are put into groups based on which chemicals in the brain they
affect. There are many different kinds of antidepressants, including:

Selective serotonin reuptake inhibitors (SSRIs)
o citalopram (brand name: Celexa)
o escitalopram (brand name: Lexapro)
o fluoxetine (brand name: Prozac)
o paroxetine (brand names: Paxil, Pexeva)
o sertraline (brand name: Zoloft)
These medicines tend to have fewer side effects than other antidepressants. Some
of the side effects that can be caused by SSRIs include dry mouth, nausea,
nervousness, insomnia, sexual problems and headache.

Tricyclics
o amitriptyline (brand name: Elavil)
o desipramine (brand name: Norpramin)
o imipramine (brand name: Tofranil)
o nortriptyline (brand name: Aventyl, Pamelor)
Common side effects caused by these medicines include dry mouth, blurred vision,
constipation, difficulty urinating, worsening of glaucoma, impaired thinking and
tiredness. These antidepressants can also affect a person's blood pressure and
heart rate.

Serotonin and norepinephrine reuptake inhibitors (SNRIs)
o venlafaxine (brand name: Effexor)
o duloxetine (brand name: Cymbalta)
Some common side effects caused by these medicines include nausea and loss of
appetite, anxiety and nervousness, headache, insomnia and tiredness. Dry mouth,
constipation, weight loss, sexual problems, increased heart rate and increased
cholesterol levels can also occur.

Norepinephrine and dopamine reuptake inhibitors (NDRIs)
o bupropion (brand name: Wellbutrin)
Some of the common side effects in people taking NDRIs include agitation, nausea,
headache, loss of appetite and insomnia. It can also cause increase blood pressure
in some people.

Combined reuptake inhibitors and receptor blockers
o trazodone (brand name: Desyrel)
o nefazodone (brand name: Serzone)
o maprotiline
o mirtazpine (brand name: Remeron)
Common side effects of these medicines are drowsiness, dry mouth, nausea and
dizziness. If you have liver problems, you should not take nefazodone. If you have
seizures, you should not take maprotiline.

Monamine oxidase inhibitors (MAOIs)
o isocarboxazid (brand name: Marplan)
o phenelzine (brand name: Nardil)
o tranlcypromine (brand name: Parnate)
MAOIs are used less commonly than the other antidepressants. They can have
serious side effects, including weakness, dizziness, headaches and trembling.
Taking an MAOI antidepressant while you're taking another antidepressant
or certain over-the-counter medicines for colds and flu can cause a dangerous
reaction. Your doctor will also tell you what foods and alcoholic beverages you
should avoid while you are taking an MAOI. You should not take an MAOI unless you
clearly understand what medications and foods to avoid. If you are taking an MAOI
and your doctor wants you to start taking one of the other antidepressants, he or
she will have you stop taking the MAOI for a while before you start the new
medicine. This gives the MAOI time to clear out of your body.