Schizophrenia Flashcards
What is schizophrenia?
Chronic and severe mental disorder that is characterised by distortion of thoughts, behaviours/mood and perception. There is cognitive impairment.
What is psychosis?
perceive or interpret things different from those around them may involve delusions or hallucinations.
Diagnostic criteria
2+ of (1)delusions, (2)hallucinations, (3)disorganised speech, (4)grossly disorganised or catatonic behaviour, (5)negative symptoms. Need to have them for a least 1 month, and at least 1 of (1), (2) or (3). Disturbs functioning in social or work area compared to functioning before. Continuous signs of disturbance persist for at least 6 months. Schizoaffective disorder ruled out.
What is paranoia?
Irrational and persistent feeling that people are ‘out to get you’.
What is schizoaffective disorder?
Different from SZ. It has both symptoms of SZ and either depression or bipolar disorder. 2 major types of SZ affective disorder: bipolar and depressive type. Period during which major mood disorder: depression or mania plus SZ symptoms.
What are positive and negative symptoms?
Positive: hallucinations, delusions, thought disorder and disorganised speech.
Negative: absence of normal response/behaviours, reduced emotional expression, social withdrawal, poverty of speech,.
What are types of SZ?
Catatonic or paranoid
What causes SZ?
Strong genetic component as well as environmental.
Afro-caribbean males in UK are 6-8 times more likely to get SZ, slow viral infection?, associated autoimmune process? maternal nutrition, developmental abnormality. Thought to be genetic predisposition with environmental trigger. Traumatic events during development.
What are the hypotheses behind SZ?
DA hypothesis
Glutamate hypothesis
What does the DA hypothesis in terms of pathways and symptoms say?
Mesocortical pathway - cell bodies from ventral tegmental area axons go into cortex - hypofunction –> negative symptoms.
Mesolimbic pathway - cell bodies in the same area have axons going to limbic area of brain - hyperfunction –> positive symptoms.
Which symptoms; negative or positive symptoms respond best to neuroleptics?
Positive symptoms
What are typical neuroleptics?
Typical: dirty drugs, multiple targets - D1, D2, D3, H1, 5-HT, NA. Better for positive symptoms. Side effects problematic. Receptor antagonists. Antipsychotic activity through DA receptor block. D2 important for antipsychotics. 3 main classes: -phenothiazines e.g. chlorpromazine -butyrohenones e.g. haloperidol -thioxanthines e.g. flupenthixol
What are atypical neuroleptics?
How they different from typical neuroleptics. Different pharmocological profile e.g. higher DA receptor selectivity. Fewer motor side effects, more effective against negative symptoms and TRS.
- MARTAs e.g. clozapine
- 5-HT e.g. risperidone
- D2 antagonists e.g. sulpiride
What are the side effects of neuroleptics?
dopaminergic - anti-emetic, increased prolactin release and EPS
Anti-emetic due to DA receptor block in TZ, H1 block also important.
Endocrine - increased prolactin release by pituitary, release normally inhibited by DA, D2, neuroleptics block inhibition so breast swelling, pain and lactation.
Motor disturbance - acute: dystonias, chronic: tardive dyskinesia
What are the motor side effects of neuroleptics?
Due to blockade of DA receptor in striatum you get dystonias; involuntary movements (face, tongue, neck), parkinsonian; tremor at rest, muscle rigidity and reduced mobility. Developed relatively rapidly and reversible.
Tardive dyskinesia: severely disabling motor disturbance, involuntary movements of face, tongue, slowly developing, chronic treatment, generally irreversible, serious but not produced by all eurlopetics, EPS.
Non-DA: related to block of other receptor sites: anti-muscarinic: dry mouth, constipation, visual disturbances, postural hypotension due to alpha receptor block, sedation due to H1.
