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New Technologies in
the Treatment of Mood Disorders
Treatment
for depression and bipolar disorder (also known as manic depression)
usually includes talk therapy, medication and support from people who
understand. Sometimes people do not respond to traditional treatments or
need additional help managing symptoms. Today many researchers are
focusing their attention on technology to develop new, more effective
treatments.
Looking
At Where We’ve Been To Understand Where We’re Going
Scientists
believe that depression and bipolar disorder are caused by an imbalance
of brain chemicals, called neurotransmitters. Medications used to treat
these illnesses work to change brain chemistry and correct this
imbalance.
In
the 1930s, researchers discovered that applying a small amount of
electrical current to the brain caused small mild seizures that changed
brain chemistry. Over the years, much has been done to make this form of
treatment, electroconvulsive therapy (ECT), milder and easier for
patients to tolerate. ECT is used to treat about 100,000 patients with
depression each year. It is very effective in treating severe
depression. However, there can be side effects such as confusion and
memory loss. The procedure must be performed in a hospital with general
anesthesia.
This
concept of altering brain function and chemistry with outside
stimulation led to the development of several new treatments. They are
now being tested to determine their safety and effectiveness in treating
depression.
Note:
Various
clinical trials (research studies) investigating treatments for
effectiveness and safety in treating depression and bipolar disorder are
underway. Participation in clinical trials requires careful
consideration and discussion with your doctor. For information on
clinical trials and what to consider before entering one, visit www.DBSAlliance.org/info/clinical.html.
Transcranial Magnetic Stimulation (TMS)
One procedure under investigation is Transcranial Magnetic Stimulation
(TMS). TMS was developed in 1985 and has been studied as a treatment for
mental illness since 1995. In TMS therapy, a special electromagnet
delivers short bursts of energy to stimulate nerve cells in the brain.
This helps correct the existing chemical imbalance. Research studies
have shown this treatment can have beneficial results. It has been shown
to be as effective as other depression treatments, and is generally free
of the side effects that are most commonly seen with antidepressant
medication. Clinical trials are ongoing.
Early TMS machines delivered a magnetic pulse every second. They are used
by neurologists to diagnose nerve damage. Advances in the technology
have resulted in machines that are capable of delivering up to 50 pulses
per second. Studies have shown that certain types of this rapid rate TMS
(rTMS) can have beneficial effects for some patients.
TMS therapy can be performed in a physician’s office. It does not
require surgery, hospitalization, or anesthesia. A small hand-held
device placed against the scalp delivers short magnetic pulses that
affect the brain. The energy from the TMS device can be focused on a
specific area of the brain, which may allow for more precise treatment
than ECT. TMS sessions generally take 30 minutes. Current research
suggests that treatment is most effective when given five days per week
for two to four weeks.
The side effects associated with TMS are mild and relatively infrequent.
Some patients report a slight knocking or tapping sensation on the head.
This may be a result of the tapping sound produced by the TMS device.
Some patients report feeling slight muscle contractions on the scalp.
Others experience a mild headache or lightheadedness, which usually goes
away soon after the treatment session.
The Food and Drug Administration has not yet approved TMS for treatment
of depression. As with any medical procedure, there are some risks
associated with TMS. The main risk is that the device could cause a
seizure, though current treatment guidelines make this extremely rare.
No memory loss or difficulty in concentration has been reported in any
research study to date.
Vagus
Nerve Stimulation (VNS)
The vagus nerves, the longest nerves in the human body, run from the
brain down each side of the neck, through the esophagus and into the
gastrointestinal tract. In the brain the vagus nerves travel through the
areas that control sleep and mood. Vagus Nerve Stimulation (VNS)
involves implanting a small battery-powered device, similar to a
pacemaker, under the skin on the left side of the chest. An insulated
tube containing electrodes (called the lead) runs from the device to the
vagus nerve on the left side of the neck. The device is programmed by a
doctor to deliver a mild electrical stimulation to the brain at regular
intervals. The patient can also use a special magnet to turn the device
on and off. This stimulation triggers activity in the brain that may
work to correct the chemical imbalance that causes depression. The Food
and Drug Administration has approved VNS as a therapy for preventing
epileptic seizures. VNS is not yet approved for the treatment of
depression. Clinical trials are ongoing.
The most common side effects reported by people who use VNS therapy are
hoarseness, sore throat and shortness of breath. People with the VNS
device are advised to follow the same precautions as someone who has a
pacemaker for heart problems.
Because it is implanted in the chest, the VNS device may interfere with
proper imaging during a mammogram. This can be prevented by adjusting
positioning during the procedure. Once the device is implanted, it can
be difficult to remove it.
Some medical procedures may affect the VNS device. These include
diathermy, a treatment used to promote healing and relieve pain,
procedures used for heart problems, and ultrasound. People planning to
have magnetic resonance imaging (MRI) should use special caution. Inform
your doctor you have a VNS device before having any medical procedure.
Studies have shown that VNS can have beneficial results, especially for
individuals who have not found relief with other treatments.
Magnetic
Stimulation Therapy (MST)
One of the newest procedures under investigation for the treatment of
mood disorders is Magnetic Stimulation Therapy (MST). MST uses powerful
magnetic fields to induce a small, mild seizure, similar to one produced
through ECT. Research studies involving people have only recently begun.
Researchers believe MST will be able to treat specific areas of the
brain. It is hoped that this treatment will not affect memory or
concentration. However, because the procedure causes a seizure, general
anesthesia is required.
A
Promising Future
Emerging technologies such as TMS, VNS and MST offer hope to people who
are coping with treatment challenges. It may take some time for these
treatments to be adequately studied so that we more completely
understand their potential risks and benefits. At this point, the future
looks promising. As with any treatment, different people will have
different responses. All individuals are advised to work with their
doctors in collaborative partnerships to find the treatments that work
best for them.
For
more information
Questions
to Ask Your Doctor
-
When
will I start to feel some improvement?
-
What
might the side effects of my treatment be? How can I cope with them?
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What
are the risks associated with my treatment?
-
How
can I recognize problems if they happen?
-
How
can I reach you in an emergency?
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What
can I do to improve my response to this treatment?
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How
will this treatment affect the treatments I’m receiving for other
illnesses?
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