Biological Therapies for Schizophrenia

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Biological Therapies for Schizophrenia

1.       Drugs

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.

 

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.

 

Anti-psychotic drugs

          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

Bennett 2006

          Year 1 – relapse rates of 40% in 1st year

          15% in successive years

          Appear to delay relapse rather

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