Drugs and Mental Health Flashcards
What are anxiety disorders?
An inappropriate sympathetic response
What is the most effective anxiolytic?
Benzodiazepines
What is the mechanism for benzodiazepines?
Enhances GABA response by selectively bind to GABAa receptors and facilitating opening of GABA activated chloride channels
What are unwanted effects of benzodiazepines?
Prolonged sleep Respiratory depression Impaired coordination High tolerance Withdrawal likely
What defines a major depressive episode?
Sad, depressed mood for 2 weeks Loss of pleasure Disruption of appetite and sleep Negative self concepts Recurrent thoughts of death
What is the biogenic amine hypothesis?
The theory used to explain depression - decreased noradrenaline, serotonin or dopamine
What are the three classes of antidepressants?
Tricyclic antidepressants
Monoamine oxidase inhibitors
Selective serotonin reuptake inhibitors
Why aren’t tricyclic antidepressents prescribed anymore?
They are cardiotoxic
Describe the mechanism of monoamine oxidase inhibitors
They inhibit the enzyme monoamine oxidase that breakdown noradrenaline, serotonin and dopamine at the synaptic cleft
Describe the mechanism of selective serotonin reuptake inhibitors
The SSRI blocks the reuptake of serotonin which increases the concentration of serotonin. This desensitises 5-HT1a autoreceptors so there is a lack of inhibition of impulses. This increases the serotonin from the axon terminal and the post synaptic receptors also desensitise
What is the effect of the mechanism of SSRIs on the therapeutic timeline?
It takes two weeks to have a therapeutic effect
Where are 5HT1a receptors located?
On the somata and dendrites in the raphe nuclei of the medulla and midbrain
Why are 5HT1a receptors classed as autoreceptors?
They are located on serotonergic neurones and bind to serotonin
What are unwanted effects of SSRIs?
Nausea, anorexia, insomnia, aggression, sexual dysfunction, loss of libido
What are positive symptoms of schizophrenia?
Delusions
Hallucinations
Disordered thinking
What are negative symptoms of schizophrenia?
Apathy
Depression
Withdrawal from society
Describe the dopamine hypothesis of schizophrenia and how it was proposed
Hyperactive dopamine release causes schizophrenia
Drugs that cause dopamine release or agonise dopamine receptors cause schizophrenic like behaviours
What is the action of all clinical antipsychotics?
Dopamine receptor antagonists
What are problems with antipsychotics?
Don’t affect negative symptoms
Many patients respond poorly
Many patients are non-compliant to treatment
What are unwanted effects of antipsychotics?
Extrapyrimidal syndrome - spasms & involuntary movement
Increased prolactin - milky discharge from nipples, gynaecomastia, infertility
Blockage of muscarinic receptors - dry mouth, blurred vision
What are the benefits of antipsychotics having atropinic effects?
These drugs have a reduced risk of extrapyrimidal syndrome
