Principles Of Neuroscience Lecture 32 Disorders Of Mood And Thought Flashcards
What role does gender have in terms of a risk factor for mental disorders?
The different genders are more likely to sufferer from different mental disorders
Male: autism, ADHD, substance abuse
Female: anxiety, major depressive disorder, eating disorders
What is the aetiology of mental disorders?
Complex
Many different genetic and environmental effects
What are the most significant mental disorders?
Schizophrenia
Major depressive disorder
Manic depression
Panic disordedr
What is another name for major depressive disorder?
This is another name for affective disorder
What is the DSM IV for major depressive episodes?
Four or more from a list of symptoms over a two week period, which must include either:
- Depressed mood
- Disinterest in pleasure
Features of behaviour; dark, negative moods and preoccupation with one’s inadequacy
What is bipolar also known as?
Manic depression
What are the features of manic episodes?
- elevated mood
- aboundless energy
- high creativity
- loss of interest in sleep
- Profusion of thought
- grandiosity
- aggression and anxiety
What are the abnormalities in blood flow during major depressive episodes?
There is increased blood flow to three areas during major depressive episodes:
- orbital and medial frontal lobes
- thalamus
- amygdala
What is interesting about the musical output of Robert Schumann?
Schumann suffered from manic depression
In the periods of mania, he wrote a huge volume of music
When he was depressed, he wrote almost nothing
This exemplifies the profusion of thought and creativity during the manic episodes
What are the categories of treatment of major depressive disorder? (3)
- Electroconvulsive therapy
- Psychotherapy: the talking cure
- Antidepressant drugs
What is a treatment for manic depression?
Lithium, discovered by accident
We still really know how it works, but it seems to change second messenger pathways that lead to manic depression
What are the three classes of drugs to treat major depressive disorder?
- Tricyclics
- SSRIs and NERIs
- MAO-A inhibitors
What is the function of tricyclics?
These block the reuptake of serotonin and noradrenaline
What is the function of SSRIs and NERIs?
Selective serotonin reuptake inhibitor: this drugs only blocks serotonin from being taken up again
Noradrenaline reuptake inhibitor: only blocks the reuptake of noradrenaline
What are some examples of SSRIs?
Prozac, Zoloft, Paxil
What is the function of MAO-A inhibitors?
These block the enzyme that breaks down monoamines: the Monoamine oxidase enzyme.
Monoamines are thus not broken down, and hang around longer in the synapse
What are the general features of the action of antidepressant drugs?
What do they target?
Antidepressents drugs act in e synapse; target any part of synaptic transmission:
- Neurotransmitter synthesis
- Neurotransmitter storage
- Vesicle release
- Breakdown
- Reuptake
- Post-synaptic transmission
Which sort of synapses do antidepressant drugs target?
The synapses of the neuromodulatory systems
Compare and contrast ionotropic and metabotropic receptors
Ionotropic: ligand binds, and the receptor, which is an ion channel, opens and ions move across the membrane
Metabotropic: ligand binds to the receptor. G protein is activated, and then goes on to open an ion channel, or activate a target protein
Which sort of receptors are seen in the neuromodulatory systems?
Metabotropic
What are the prodromal signs of schizophrenia?
- Social withdrawal
- Neglect of hygiene
- Odd ideas and behaviour
- Paucity of speech
What are negative symptoms?
These are the absence of a certain feature; such as the lack of speech
What are the two types of symptoms that must be present for a diagnosis of schizophrenia?
The characteristic symptoms
Social and occupational dysfunction
What are the characteristic symptoms of schizophrenia?
- Hallucinations
- Catatonic behaviour
- Delusions
- Disorganised speech
- Affective flattening (no emotional expression)
Describe the social and occupational dysfunction seen in schizophrenia
- Decreased performance at work
- Poor interpersonal relationships
- Lack of self care
Describe the features of acute psychotic episodes
- Paranoia
- Auditory hallucinations
- Misattribution of significance
- Spiritual / supernatural experiences
Describe the evidence for genetic predisposition to schizophrenia
If someone suffers from schizophrenia, the more closely related you are to that persons the higher the chance that you too will develop schizophrenia.
Eg. If one monozygotic twin has schizophrenia, there is a 48% chance of the other twin having it
What anatomical features are seen in schizophrenia?
Reduced brain volume –> increased ventricle volume
Increased space between the hemispheres
What is the dopamine hypothesis?
Which disorder does it refer to?
This refers to schizophrenia
This is the hypothesis is that schizophrenia is due to overactivity of dopaminergic pathways
What is the criticism for the dopamine hypothesis?
Too simplistic
- Some individuals don’t respond to dopamine antagonists, but instead to Monoamine antagonists
- PCP is a drug that causes schizophrenia, however, it acts on glutamate receptors, not dopamine receptors
- dopamine antagonists bind immediately, but relief of the symptoms takes a while
What is PCP?
What is its function?
This is a drug also known as Angel dust
The drug binds to glutamate receptors, blocking them so that the neuron can not be depolarised
Describe the experiment in which mice had glutamate receptors knocked out
The mice with glutamate receptors knocked out exhibited social withdrawal
What is the evidence for the dopamine hypothesis?
- The higher affinity of a drug to the dopamine receptor, the lower the dose required to provide relief of the symptoms of schizophrenia
