Download Biological treatments of mood disorders

Biological Treatments of Depression
1. Drug Therapy
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Tricyclic antidepressants (TA)
Monoamine oxidase inhibitors (MAOIs)
Selective serotonin reuptake inhibitors (SSRI’s)
TA were initially used in 1958 and work by preventing noradrenalin and serotonin being taken back into the neuron
after it has been released. The effect of the drug is to increase the activity of those neurotransmitters.
These drugs have a number of undesirable side effects including dry mouth, excessive perspiration, constipation, blurring
of vision and sexual dysfunction. They are effective in 605 of the patients treated however they can take a long time to
have an effect (6-8 weeks). They can also be fatal if an overdose is taken which is only 5 times the recommended dosage.
MAOIs work by preventing the breakdown of the monoamine oxidase chemical in the presynaptic neuron. Stopping
the activity of MAO means that higher levels of neurotransmitters are active in the brain.
The side effects: MAOIs are rarely prescribed now, because patients taking them must avoid tyramine rich foods such as
cheese and chocolate. If this special diet is not adhered to patients risk liver damage, high blood pressure, strokes and
even death.
SSRIs is the most recent type of antidepressant with the most well known being Prozac. They allow serotonin to
remain longer actively in the synapse.
These are fast acting bring relief to depression around 2 weeks. They do have less severe side effects but can increase a
person’s feelings of anxiety and agitation and there can also be an increase of suicide rates.
The treatment of bipolar disorder - Mood stabilisers
Lithium – Returns the neurotransmitter levels dopamine and serotonin back to normal. IOt is most effective for
treating mania rather than depression. Sufferers must take these drugs for the rest of their lives. The uptake of the
drug depends on the person concerned.
There are also undesirable side effects such as blurred vision, difficulty in concentration and kidney dysfunction. A
problem with bipolar patients is that they do not like taking the drug – cease and so problems return. This is especially
true as when the individual is not in the manic phase they think they are better and stop their medication.
Other evaluations
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Drug treatment is relatively inexpensive and easy to sustain compared with psychological treatments.
The three classes of antidepressants do reduce depression but unfortunately not everyone responds to them
They take time to work and so the individual must wait with difficulty until it kicks in.
The drugs for unipolar and SAD are not effective for bipolar especially mania.
Most drugs have unpleasant side effects. Sometimes these can be quite disabling.
Drugs do not actually cure mental illness although they do relieve symptoms.
QUESTIONS
1. Name the three most commonly used chemical name antidepressants that exist in the market today.
2. Which drug is more commonly used to treat depression and why?
3. What type of mood disorder is lithium used to treat?
4. What mode of action takes place whereby Lithium gets to work?
5. How do MAOI’s work and why are they rarely used today?
6. List three of the main problems when using drug therapy.
Other biological treatments
1. Electroconvulsive therapy
2. Psychosurgery/lobotomies
ECT:
http://www.youtube.com/watch?v=EGZv2wbYV7U&feature=related
LOBOTOMIES:
http://www.youtube.com/watch?v=_0aNILW6ILk&feature=PlayList&
p=F57F8BD504726422&playnext=1&playnext_from=PL&index=42
(A DIFFERENT BIOLOGICAL THERAPY)
Electroconvulsive Therapy (E.C.T.)
E.C.T. is usually successful in treating severe depression that has not responded to drugs, especially if there is a serious
risk of suicide. It is an effective treatment that acts relatively quickly (Wesseley 1993, cited in Gross and McIlveen 1996).
Two electrodes are placed on her forehead (either to one side, for unilateral ECT or on either side, for bilateral ECT).
An electrical current is then passed between the electrodes for about half a second (Eysenck 1994). Around seven to
nine treatments are given, depending on how quickly the patient’s mood lifts, (Comer 1995).
Mode of action.
Unfortunately nobody yet knows how ECT improves mood. It has been suggested that it is the associated memory loss
that reduces depression. However, unilateral ECT, which has less effect upon memory is also effective. One plausible
suggestion is that ECT produces changes in the biochemistry of the brain, perhaps affecting the levels of serotonin and
noradrenaline.
Side effects.
ECT was a painful and distressing procedure in the days before muscle relaxants were given and people had to be
physically restrained when fitting. Patients would sometimes sustain injuries when given ECT, including bruises and
fractures. Today, ECT is considered a low risk procedure but is still only given when other treatments have failed. Side
effects include loss of memory for events preceding the treatment and, more seriously, a general impairment of memory
which can last for months (Eysenck 19940). Occasionally, bilateral ECT can lead to impaired speech and for that reason
unilateral treatment is preferably administered to the non -dominant right hemisphere (most people’s speech centre is in
the left side of the brain).
ECT- Electroconvulsive therapy
50yrs +
Controversial
Anaesthetised/muscle relaxant – electrodes temples of head
Electricity passes through brain 6-12 sec (1 min seizure)
Last resort
Fink, 2001 – 50% patients helped
How does it work? Produces changes in the biochemistry of the brain, affecting the levels of serotonin and
noradrenalin.
 Side effects, Memory loss, impaired speech, injuries
 80% relapse
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(A FINAL BIOLOGICAL THERAPY)
Modern Psychosurgery.
Despite the numerous drawbacks of early attempts at brain surgery, psychosurgery is still occasionally carried out.
Modern day psychosurgery involves the destruction of tiny amounts of brain tissue in ‘precisely located’ areas (Gross and
McIlveen 1996) e.g. tractotomies interrupt pathways between the limbic system (which plays a role in emotion) and the
thalamus. They can reduce the risk of chronically depressed people committing suicide from 15% to 1% (Verkaik 1995,
ibid).
Lobotomies
Modern day psychosurgery involves the destruction of tiny amounts of brain tissue in ‘precisely located’ areas (Gross and
McIlveen 1996) e.g. it interrupts pathways between the limbic system (which plays a role in emotion) and the thalamus.
They can reduce the risk of chronically depressed people committing suicide from 5% to 1% (Verkaik 1995, ibid).
Evaluations:
Hoffman (1949) writes: "these patients are not only no longer distressed by their mental conflicts but also seem to have
little capacity for any emotional Experiences or pleasure. Patients have been described as passive and flat.