Biological Therapies for Schizophrenia

An Introduction Prior to introduction of antipsychotic drugs there was no effective treatment for schizophrenia. Following the discovery of dopamine in 1952, drugs were developed that had a direct effect on the action of this neurotransmitter. Some drugs, such as amphetamines, were found to create the symptoms of schizophrenia in healthy people, while others markedly reduced these symptoms. Drugs which had this effect became known as antipsychotics.

Biological Therapies for Schizophrenia According to the biological approach, schizophrenia arises from brain abnormalities or illness with due to underlying biological factors. Therefore biological treatments have been developed. These include electro-convulsive therapy (ECT) and psychosurgery. Most people will receive drug therapy.

Biological Therapies for Schizophrenia Early Treatments for Schizophrenia In the past, many people with schizophrenia were hospitalised and spent years in institutions because no effective treatments were available. Wards became overcrowded and the priority for staff was to keep order rather than provide humanitarian therapy. This was often achieved by restraint.

Biological Therapies for Schizophrenia Early Treatments for Schizophrenia One early form of treatment was performed by Moniz in This was the prefrontal lobotomy, a form of psychosurgery where sizeable portions of brain tissue were destroyed. This operation was carried out extensively on the mentally ill – many of whom met the criteria for schizophrenia.

Biological Therapies for Schizophrenia Early Treatments for Schizophrenia There was no evidence that this drastic treatment was effective but plenty of evidence to show that it caused serious, life-threatening side effects and so was inappropriate. It was eventually abandoned when antipsychotic drugs were developed.

Biological Therapies for Schizophrenia Early Treatments for Schizophrenia With the introduction of sophisticated equipment and techniques, psychosurgery is a much more refined process, however, it is only used as a last resort an rarely in cases of schizophrenia.

Biological Therapies for Schizophrenia Electroconvulsive Therapy Inducing seizures. Another controversial therapy. Little effect on disorder - has been largely abandoned. Karagulla (1950) lower rates of recovery associated with this treatment.

Biological Therapies for Schizophrenia Electroconvulsive Therapy What happens in ECT? An electric current is passed through the brain. The patient is injected with barbiturate so they are unconscious. They are then given a nerve blocking agent, paralysing the muscles of the body to prevent them contracting and causing fractures. Seizures last about half a second and patients usually require between 3 and 15 treatments.

Biological Therapies for Schizophrenia Electroconvulsive Therapy Tharyan and Adams (2005) – reviewed 26 studies including 798 participants in total in order to assess the benefits of ECT for schizophrenia. These included a wide range of studies that compared ECT with a placebo condition (simulated ECT) and with antipsychotic medication.

Biological Therapies for Schizophrenia They found that when ECT was compared with ECT placebo – more people improved in the ECT condition. However, there was no evidence that this was maintained in the long-term. When ECT was compared with the antipsychotic treatment, the medication groups had better results.

Biological Therapies for Schizophrenia There was little evidence to support combining these methods. However, may be appropriate when rapid reduction of symptoms is required or when patients show limited response to medication alone.

Biological Therapies for Schizophrenia There was little evidence to support combining these methods. However, may be appropriate when rapid reduction of symptoms is required or when patients show limited response to medication alone.

Biological Therapies for Schizophrenia Electroconvulsive Therapy American Psychiatric Association Review (2001) – looked at 19 studies that compared ECT with simulated ECT. ECT produced results which were no different from or worse than antipsychotics. Risks Memory dysfunction, brain damage, death – use of this treatment has declined.

Biological Therapies for Schizophrenia Drug Therapy Most common form of treatment – antipsychotics. Some drugs work by reducing the activity of dopamine, others work by reducing the serotonin activity. Conventional antipsychotics (typical) – dopamine Atypical antipsychotics - serotonin

Biological Therapies for Schizophrenia Drug Therapy Drugs help people function as well as they can in their everyday life and increase their feeling of subjective well being. Typical (antipsychotics - chlorpromazine) – positive symptoms Atypical (clozapine) – positive symptoms but also claimed to have beneficial effects on negative symptoms.

Biological Therapies for Schizophrenia Drug Therapy Conventional Antipsychotics Reduce effects of dopamine – reduce symptoms of schizophrenia. The drugs bind to dopamine receptors but do not activate them, they work by blocking them. By reducing stimulation of dopamine – hallucinations etc are reduced/eliminated. Maximum benefits in first six months of use.

Biological Therapies for Schizophrenia Drug Therapy Atypical Antipsychotics These take effect by blocking serotonin rather than dopamine receptors.

Biological Therapies for Schizophrenia Drug Therapy Effectiveness of Antipsychotics -Rapidly reduce the most disturbing symptoms. -Have a sedative effect and patients can live a relatively normal life in their community. People do not need to endure long stays in hospitals and may be able to be seen as out-patients.

Biological Therapies for Schizophrenia Drug Therapy Effectiveness of Antipsychotics -Relapse – studies comparing effects of antipsychotics with placebo drugs generate support. -Davis et al (1980) – analysed results of 29 studies. 55% of those whose drugs were replaced by placebo relapsed compared to 19%. -Ross and Read – 45% did benefit from placebo. -When the drug is stopped completely symptoms have been shown to reoccur – require them long-term. Increases side effects.

Biological Therapies for Schizophrenia Drug Therapy Effectiveness of Antipsychotics -Relapse also depends on living environment. -Davies et al - genuine medication in a hostile home environment – 53% -Placebo + hostility = 92% -Living in supportive homes reduced relapse – no difference between medication an placebo.

Biological Therapies for Schizophrenia Drug Therapy Appropriateness Side effects – conventional antipsychotics produce some serious side effects – raise doubts about their appropriateness. One is the development of symptoms of Parkinson's, such as stiffness, immobility and tremors.

Biological Therapies for Schizophrenia Drug Therapy Appropriateness Can lead to a disorder called ‘tardive dyskinesia’ (Uncontrollable smacking and sucking of the lips.) It is thought this maybe due to the drugs destroyed parts of the brain. Occurs in about 30% and increases with prolonged use.

Biological Therapies for Schizophrenia Drug Therapy Appropriateness Other side effects: low blood pressure, blurred vision; constipation. Newer drugs are no more effective and cause slightly fewer side effects – Girgis et al (2011). However, clozapine – potentially life-threatening – damage to the immune system. Other drugs have to be administered to counter this and regular blood tests are needed. This makes it expensive and limits its availability.

Biological Therapies for Schizophrenia Drug Therapy Compliance Some patients refuse to comply with drug treatment regimes, possibly because of the side effects. This can lead to revolving door syndrome – discharged from hospital then return. To solve this – depot antipsychotics – injection Medication is released slowly over a few weeks rather than taking tablets daily. Another strategy is ‘motivational interviewing’ – to encourage patients to weigh advantages and disadvantages of medication. Patients more likely to comply and effectiveness improved.