Biological Therapies

1. Drugs

The main classes of drugs are described below:

• Anxiolytic drugs (anti-anxiety) such as benzodiazepines and beta-blockers are used to treat stress and anxiety.

• Anti-psychotic drugs are used to treat psychotic illnesses such as schizophrenia. The biological approach to abnormality suggests that there are physical causes for mental disorders. If one believes that mental disorders have a physical basis

  then it follows that they should be treated using physical or somatic methods (soma = body).

  • Typical anti-psychotics, for example, chlorpromazine, are used to treat the positive symptoms of schizophrenia, such as hallucinations. They bind to dopamine receptors at the ends of neurons and block the action of dopamine, reducing the positive symptoms.

  • Atypical anti-psychotics, such as clozapine, treat negative symptoms, such as reduced emotional expression, as well as positive symptoms of schizophrenia. They act on the serotonin system as well as the dopamine system by temporarily occupying receptor sites and then allowing normal transmission. This may explain why side effects are less severe than when typical anti-psychotics are used.

• Anti-depressant drugs (stimulants), such as Prozac, promote activity of noradrenaline and serotonin, which leads to increased arousal but can be affected by rebound (depression after initial euphoria).

  • Tricyclics increase activity of these neurotransmitters by blocking their reuptake. When a neuron fires, the neurotransmitters are released into the synapse affecting the adjoining neuron; they are then re-absorbed by the neuron, preventing further action. By blocking re-uptake the neurotransmitter levels are increased.

  • SSRIs (selective serotonin re-uptake inhibitors) block mainly serotonin.

  • Selective noradrenaline re-uptake inhibitors are also now available.

Evaluation of drug therapy:

• Drug treatment is easy, requiring little effort from the patient.

• Drugs can be particularly effective when used in conjunction with psychotherapy. They can relieve some of the disabling symptoms and allow the contributing psychological factors to be dealt with.

• The use of drug therapies has offered significant relief to many sufferers. For example, WHO (2001) reported that schizophrenics were less likely to relapse when taking anti-psychotics. Relapse is a key issue when evaluating treatments for mental disorders. A patient may be relieved of their symptoms for a while but then ‘relapse’, i.e. go back to having the same symptoms. Therefore, there may initially appear to be a cure (and this is cited as a success for the therapy) but this ‘cure’ is only temporary. 
• The advent of drug therapies in the 1950s led to a large decrease in the number of people in mental institutions.
• However, some of this success may be due to the psychological effects of drugs. Kirsch et al. (2002) reviewed 38 studies of anti-depressants and found that treatments using placebos were almost as effective as using drugs. Placebos are substances that have no pharmacological effects, but the person taking them thinks they are the real thing. This means you can separate the psychological from the physical effects of being given a drug treatment.
• There are problems of addiction and dangerous side-effects. For example, anti-psychotics cause tardive dyskinesia (involuntary movements of the mouth and tongue). Other symptoms range from high blood pressure to constipation. Such effects explain why many patients stop taking drugs, which is a key reason why they do not work.
• Drugs are not cures. They are short-term remedies that very often become long-term. They may mask the underlying problem, preventing a real cure.

2. Electroconvulsive Therapy

ECT today involves little discomfort, as the patient is given an anaesthetic and a muscle relaxant. An electric shock is applied to the brain to create a seizure.

• Unilateral ECT – An electrode is placed above the temple on the nondominant side of the brain, and another electrode is placed in the middle of the forehead.
• Bilateral ECT – An electrode is placed above each temple.
• A very small electric current (about 0.6 amps) is passed through the brain for about half a second and the seizure lasts about a minute. The individual awakes soon after and remembers nothing of the treatment, which is desirable. However, they may also suffer some long-term memory loss.
• The treatment is usually given three times a week over a period of one to five weeks.

Evaluation of ECT:

• ECT appears to be successful for cases of severe depression. Janicak et al. (1985) found that 80% of all severely depressed patients respond well to ECT, compared with 64% recovery when given drug therapy. However, Sackheim et al. (2001) found that 84% of patients relapsed within 6 months.
• The method is potentially dangerous (death from using anaesthetic) and there are side effects such as memory loss, fear and anxiety.
• Some critics believe it should not be used because we don’t know the basis for its success – it’s like hitting a TV to make it work again. However, there are proposed explanations, such as suggesting that the seizure may re-structure disordered thinking or it may alter the biochemical balance of the brain and thus lead to recovery.

PROGRESS CHECK

1. Identify the neurotransmitter that SSRIs enhance.
2. What is a placebo?
3. What kind of ECT affects only one side of the brain?