PSY2061 Chapter Notes - Chapter 18: Benzodiazepine, Atypical Antipsychotic, Antipsychotic
5 Jun 2018
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PSY2061 – Readings – Week 11 – Psychiatric Disorders
• psychiatric disorders - disorders of psychological function sufficiently
severe to require treatment
•
o difficult to diagnoses - usually rests entirely on the patient’s
symptom profile
o
▪ currently - diagnosis is guided by the DSM-5
▪ two main difficulties in diagnosis
▪
▪ patients suffering from the same disorder often
display different symptoms
▪ patients suffering from different disorders often
display many of the same symptoms
• schizophrenia
•
o the breakdown of integration among emotion, thought and action
o 1 per cent of populations
o typically beginning in adolescence or early adulthood
o what is schizophrenia
o
▪ symptoms are complex and diverse - also overlap with
other psychiatric disorders and frequently change during
the progression of the disorder
▪ postive symptoms
▪
▪ symptoms that seem to represent an excess of
typical function
▪ delusions
▪
▪ being controlled
▪ persecution
▪ grandeur
▪ hallucinations
▪
▪ imaginary voices making critical comments
or telling patients what to do
▪ inappropriate affect
▪
▪ failure to react with the appropriate emotion
to positive or negative events
▪ disorganised speech or thought
▪
▪ illogical thinking, peculiar associations
among ideas, belief in supernatural forces
▪ odd behaviour
▪
▪ difficulty performing everyday tasks, lack of
personal hygiene, talking in rhymes
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▪ negative symptoms
▪
▪ symptoms that seem to represent a reduction or loss
of typical function
▪ affective flattening
▪
▪ diminished emotional expression
▪ avolition
▪
▪ reduction or absence of motivation
▪ catatonia
▪
▪ remaining motionless, often in awkward
positions for long periods
▪ the frequent recurrence of any of these two symptoms for 1
month is sufficient for the diagnosis of schizophrenia -
provided one of the symptoms is delusion, hallucinations or
disorganised speech
o causal factors in schizophrenia
o
▪ genetic factors
▪
▪ many genes linked to the disorder
▪ act in combination with one another and experience
to produce the disorder
▪ differences in experience have a significant effect on the
development of schizophrenia
▪
▪ current view - some people inherit a potential for
schizophrenia which may or not be activated by
experience
▪ experiential factors
▪
▪ birth complications
▪ maternal stress
▪ prenatal infections
▪ socioeconomic factors
▪ urban birth or residing in an urban setting
▪ childhood adversity
o discovery of the first antipsychotic drugs
o
▪ a drug that is meant to treat certain symptoms of
schizophrenia and bipolar disorders
▪ chlorpromazine
▪
▪ psychosis - loss of touch with reality
▪ agitated patients with schizophrenia were calmed
▪ emotionally blunted patients were activated
▪ binds to dopamine receptors
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▪ receptor blocker - binds to dopamine receptors
without activating them
▪ chlorpromazine and other antipsychotic drugs in the
same chemical class - the phenothiazines - all bind
effectively to both D1 and D2 receptors
▪ reserpine
▪
▪ the active ingredient of snakeroot plant
▪ antipsychotic action
▪ depletes the brain of dopamine
▪ act through the same mechanisms - similar to parkinson’s
disease
▪ haloperidol
▪
▪ butryophenones
▪ binds effectively to D2 receptors but not D1
▪
▪ suggested that schizophrenia is caused by
hyperactivity specifically at D2 receptors
rather than at dopamine receptors in general
▪ can’t explain two general findings
▪
▪ although typical antipsychotics block
activist at D2 receptors within hours -
their therapeutic effects are not
usually apparent for several weeks
▪ most antipsychotics are only effective
in the treatments of schizophrenias
positive symptoms but not negative
symptoms
o dopamine theory of schizophrenia
o
▪ the theory that schizophrenia is caused by too much
dopamine and conversely that antipsychotic drugs exert
their effects by decreasing dopamine levels
▪ revision of the theory
▪
▪ rather than high dopamine levels - the main factor in
schizophrenia was presumed to be high levels of
activity at dopamine receptors
▪ current version
▪
▪ excessive activity at D2 receptors is one factor in the
disorder but there are many other factors as well
o current research and treatment
o
▪ current research
▪
▪ atypical antipsychotics
find more resources at oneclass.com
find more resources at oneclass.com
