Mental Health Flashcards
Incidence of schizophrenia?
approx 1% develop it at some point
affects men and women in equal proportions, men tend to have an earlier onset, and women have a second incidence peak in mid-late 40s
Biological basis of schizophreia?
MRI scans show sufferers have enlarged ventricles
Genetic risk factors for schizophrenia?
there are multiple genes in creating a predisposition to schizophrenia. higher rates between families
Environmental risk factors for schizophrenia?
Prenatal problems, obstetric complications, urban/city birth, stressful life events, drug abuse
- related to dopamine production
How to genetic and environmental risk factors combine to turn into schizophrenia?
cause gene expression impairments, leading to neurochemical and metabolic changes. altered connectivity leads to impaired information processes and then the symptoms: altered behaviour, altered cognition and altered emotion
Positive symptoms of schizophrenia?
Delusions, hallucinations, disorganised speech
Negative symptoms of schizophrenia?
reduced emotion, motivation, interests, thought/speech and pleasure
Cognitive deficits from schizophrenia?
Problems with attention, memory (working and verbal), executive function
Mood symptoms of schizophrenia?
depression/anxiety, hostility/aggression, suicide
Which brain circuits/areas cause the positive symptoms of schizophrenia?
mesolimbic and striatal
Which brain circuits/areas cause the negative symptoms of schizophrenia?
mesocortical and prefrontal cortex, nucleus accumbens reward circuits
Which brain circuits/areas cause the cognitive symptoms of schizophrenia?
dorsolateral prefrontal cortex
Which brain circuits/areas cause the aggressive symptoms of schizophrenia?
orbitofrontal cortex
Which brain circuits/areas cause the affective symptoms of schizophrenia?
ventromedial prefrontal cortex
DSM-V criteria for schizophrenia?
A: at least two of: delusions, hallucinations, disorganised speech, grossly disorganised or catatonic behaviour, negative symptoms for at least one month. certain delusions or hallucinations mean no other symptoms from A need to be present.
B: social/occupational dysfunction
C: duration of at least 6 months
Impact of increased dopamine in subcortical pathways?
psychotic symptoms
What do agonists of dopamine do, and exmaple?
induce psychotic symptoms e.g. amphetamines
What do antipsychotics do?
dopamine antagonists D2
How does too much dopamine at the D2 receptors relate to the symptoms?
D2 receptors are inhibitory - so increased dopamine leads to too much inhibition, causing symptoms
Consequences of NMDA receptor hypofunction?
- can be genetic or non-genetic, triggers psychosis in early adulthood
- important in the balance of GABA (inhibitory) and glutamate (excitatory)
- hypo NMDA leads to less GABA, which leads to more glutamate. this activates cell bodies to increase dopamine, which can cause psychosis.
Examples of typical antipsychotics
haloperidol, chlorpromazine
How do typical antipsychotics work?
high affinity for dopamine D2 receptors
- only effective against positive symptoms, not negative ones
- blockade of D2 receptors can lead to motor control impairments
Examples of atypical antipsychotics
Clozapine, olanzapine, risperidone
How do atypical antipsychotics work?
higher affinity for 5HT2 (serotonin) receptors over D2
- effective against positive symptoms, and more effective than typicals against negative symptoms
- significant side effects of weight gain etc
- less motor impairments than typicals