Biological Therapies for Schizophrenia
Also known as chemotherapy - using chemicals to change the way the brain or body works.
Drug treatments for mental disorders first introduced in the 1950s - reducing the number of people permanently in hospitals.
Drugs used to treat mental disorders - psychotherapeutic drugs - alter the chemical functioning of the brain by affecting the action of neurotransmitters.
• Chemicals that transmit impulses across the microscopic gaps between nerve cells called synapses.
• Changes in the brain's neurotransmitter systems lead to changes in moods, feelings, perception and behaviour.
• Also called neuroleptics. These dampen down 'psychotic' symptoms such as delusions and hallucinations, for example, chlorpromazine and clozapine.
• Conventional/ typical: dopamine antagonists, bind to dopamine receptors & block the action.
• Unconventional / atypical: either partially block ‘d’ receptors but may also block serotonin receptors
Psychotropic Mechanisms of Action
• Psychotropic drugs can alter behavior via:
– An interaction with neurotransmitters in brain
• Some release specific transmitters
• Some block the reuptake of transmitters
• Some interact with postsynaptic receptors
• Some may act within neuron cells
– A placebo effect
• Subjects believe in the efficacy of the drug and show an actual change in function (analgesia or relief from pain shows moderate placebo effects)
How effective? (typical)
• Aim to reduce positive symptoms. Don’t cure, maintenance doses needed.
• 30% don’t respond – relapse rates high
• At preventing relapse of symptoms?
– Davis et al 1980: compared to placebo significant difference
– BUT significant difference mostly seen in SZ who had disruptive home environment.
Davidson et al 2004
• Drugs may have reduced long-term institutionalisation but have led to ‘revolving door’ pattern
– admission discharge readmission
• Year 1 – relapse rates of 40% in 1st year
• 15% in successive years
• Appear to delay relapse rather…