Psychopathology Flashcards
What introduced a biological perspective to psychology?
Wide spread psychosis led to a surge of people in mental institutions. Eventually the cause of their psychosis was identified as the bacterial infection: Syphilis which introduced the idea that biological factors could affect our psychology.
What is Schizophrenia? What are the three different types of symptoms experienced (including examples?)
Schizophrenia: a psychopathological disorder characterized by the experience of a combination of negative, positive, and cognitive symptoms.
Positive Symptoms: abnormal behaviour that has been gained; e.g. hallucinations, delusions, disorganized thoughts and speech, bizarre behaviour
Negative Symptoms: Characteristics that are absent. Can be separated into two categories:
- Impaired motivation –> reduced conversation, inability to begin or sustain activities, social withdrawal.
- Emotional dysregulation –> lack of emotional expression/flat affect, inability to experience pleasure in everyday activities.
Cognitive Symptoms: problems processing or acting on external information; e.g. memory problems, poor attention, difficulty making plans and making decisions, poor social cognition, abnormal movement patterns
What evidence is there for schizophrenia being heritable? Is it entirely genetic?
- Relatives of people with schizophrenia show a higher incidence rate than the general population, especially when it is a first degree relative
- Concordance of schizophrenia is 50% in monozygotic twins
- Multiple genes are implicated in schizophrenia including the DISC1 gene (Disrupted Schizophrenia 1).
- Children fathered by older men have increased risk of developing schizophrenia (likely because the sperm of older men have had more time to accumulate mutations caused by errors in copying the chromosomes).
- Can’t be entirely genetic otherwise the concordance in monozygotic twins would be 100%, they are genetically identical.
What does an integrated model of schizophrenia look like?
An integrated model of schizophrenia looks at the INTERACTION of factors, including biological factors and environmental.
Schizophrenia seems to be caused by a combination of biological vulnerabilities combined with exposure to stressors and developmentally critical stages (e.g. prenatal stress such as infection during pregnancy or incompatible blood types between mother and fetus).
What are some structural changes in the brain associated with schizophrenia?
Ventricle Abnormalities: people with schizophrenia often have enlarged cerebral ventricles, especially lateral ventricles. This is at the expense of other brain tissues. This is possibly caused by the DISC1 gene. Enlarged ventricles are associated with a decreased responsiveness to anti-psychotic drugs.
Cortical Abnormalities:
- Different structure and functional activity of the corpus callosum.
- Accelerated cortical thinning
- abnormal frontal cortex activity
- reduced metabolic activity in the frontal lobes
How is schizophrenia treated?
Lobotomies were used in the 30s but were ineffective at doing anything but causing severe brain damage.
First Generation Antipsychotics (e.g. chlorpromaize) were good at reducing positive symptoms but had long term side effects (e.g. dyskinesia - involuntary movement, tardive dyskinesia - involuntary movement in the face).
Second Generation Antipsychotics: act on dopamine receptors and other neurotransmitter systems (like serotonin). Not necessarily more effective but less likely to motor side effects (does cause weight gain).
What are the major premises of the dopamine and glutamate hypotheses for schizophrenia? How are they different?
Dopamine Hypothesis: schizophrenia is a result of either excessive levels of synaptic dopamine or excessive post synaptic sensitivity to dopamine. Evidence: first generation anti-psychotics are dopamine receptor antagonists and their effectiveness can be predicted based on the their affinity to the receptors (higher affinity = higher effectiveness)
Glutamate Hypothesis: schizophrenia is caused, in part, by an under stimulation of glutamate receptors. This could explain the reduced activity in the frontal cortex. Problem: NMDA stimulants (glutamate receptor stimulants) cause severe seizures. Researchers are still working on developing safe anti-psychotics that also target glutamate receptors.
What is the hypo-frontal hypothesis?
The theory that schizophrenia may be caused by under-activation of the frontal lobes.
What is the most common psychopathological disorder?
Mood Disorders
Define depression.
A psychological disorder characterized by symptoms such as: unhappy mood, loss of interests, low energy, loss of appetite, and difficulty concentrating.
What are some biological factors (including brain structural differences) that are associated with depression?
- An interaction of multiple genes contribute to depression
- Monozygotic twins have a 40% concordance rate.
- Brain changes associated with depression include:
- -> increased amygdala activity
- -> increased frontal lobe activity
- -> decreased parietal and posterioral temporal cortex activity
- -> Thinner cortex in the right hemisphere
- -> decreased volume and activity of the hippocampus
How can depression be treated?
- Used to use Electoconvulsive shock therapy (not very common today although repetitive transcranial magnetic stimulation is a more modern option.
- Most common treatment today: drugs that act on monoamine transmitters (norepinephrine, dopamine, serotonin). Drugs are called Monamine Oxidase MOA and they cause monoamines to build up in the synaptic cleft to increase the stimulation of the receptors.
Other Drug interventions: SSRIs and SNRIs
Therapy: CBT appears about as effective as most SSRIs but also has a lower rate of relapse.
What have animal models of depression demonstrated about depression?
Animal models of depression show that learned helplessness (the belief THROUGH EXPERIENCE that you don’t have control over your environment) contributes to the development of depression by decreasing serotonin.
What sleep characteristics are associated with mood disorders?
Sleep characteristics associated with mood disorders:
- Difficulty falling and staying asleep
- significantly reduced SWS (stage 3)
- often enter REM sooner after falling asleep
What is bi-polar disorder? What physiological difference is associated with BPD? How is it treated?
BPD: psych disorder where episodes of depression alternate with episodes of mania. Is associated with enlarged ventricles. Lithium is often used to treat BPD.
