Chapter 12: Psychopathology Flashcards
Describe some of the features of schizophrenia
Schizophrenia is a severe psychological disorder characterized by negative symptoms such as emotional withdrawal and flat affect, and by positive symptoms such as hallucinations and delusions, and by cognitive symptoms such as poor attention span.
“schizen” - to split
“phren” - the mind
positive symptoms: hallucinations, delusions, and excited motor behavior
negative symptoms: abnormality that reflects insufficient functioning. Examples include emotional and social withdrawal, and blunted affect, cognitive impairment
Describe some of the genetic causes of schizophrenia
- risk of inheriting increases with the closeness of relatives who have also been diagnosed with schizophrenia.
- twin studies show that if one twin develops schizophrenia, then the other twin has a 50% chance of developing schizophrenia
- individual genes such as D1SC1 are disrupted in schizophrenia
- stress also seems to increase the risk
List some of the structural and functional changes of the brain as a result of schizophrenia.
Ventricular abnormalities
- enlarged cerebral ventricles, especially the lateral ones
- D1SC1 protein normally regulates trafficking of molecules within neurons
- enlarged ventricles must come at expense of brain tissue
Cortical abnormalities
- people with schizophrenia differ from controls in the structure and functional activity of the corpus callosum
- accelerated loss of gray matter
- reduced activity in the frontal lobe
Describe the hypofrontality hypothesis
the idea that schizophrenia may reflect underactivation of the frontal lobes
Explain the dopamine hypothesis
The dopamine hypothesis proposed the idea that schizophrenia results from either excessive levels of synaptic dopamine or excessive post-synaptic sensitivity to dopamine.
Explain and differentiate first-generation antipsychotics and second-generation antipsychotics.
First-gen antipsychotics: an anti-schizophrenic drug that shows antagonist activity at D2 receptors
- Chlorpromazine and other antipsychotic drugs both share the action of blocking postsynaptic dopamine receptors.
- clinical findings have bolstered the dopamine hypothesis: treating those who suffer from Parkinson’s disease with l-dopa may induce schizophrenia-like symptoms, presumably by boosting the synaptic availability of dopamine.
Second-gen antipsychotics (atypical antipsychotic): an antipsychotic drug that has primary actions other than or in addition to the dopamine D2 receptor antagonism that characterizes the 1st-gen antipsychotics
- clozapine: blocks serotonin receptor types and other receptor types.
Explain the glutamate hypothesis
This is the idea that schizophrenia may be caused, in part, by under stimulation of glutamate receptors.
Drugs such as phencyclidine and psychotomimetics induce a schizophrenia-like state. Prevents glutamate from having its usual effects. Thus, it’s thought that schizophrenia results from an under-activation of glutamate.
Define depression, the genetics, and the brain changes.
Depression is a psychiatric condition characterized by such symptoms as an unhappy mood; loss of interests, energy and appetite, and difficulty concentrating.
The concordance rate for identical twins (about 60%) is substantially higher than for fraternal twins. Many genes also contribute to depression.
Brain changes:
- increased activation in amygdala seen more in depressed individuals during emotional processing
- decreased activity is evident in the parietal and posterior temporal cortex and in the anterior cingulate cortex.
- descendants of people with severe depression also have a thinner cortex across large areas of the right hemisphere
List some treatments for depression
- electroconvulsive shock therapy used as a last result
- Most common treatments are monoamine oxidase (MAO) which is an enzyme that breaks down monoamine neurotransmitters, thereby inactivating monoamine transmitters.
- SSRI’s. However, part of the benefit may be a placebo effect.
Why do more females than men suffer from depression? Also, discuss how sleep is affected in those diagnosed with depression.
- depression as a result of contraceptives and menstrual cycle. postpartum depression also suggests that a combination of hormones can precipitate depression.
- sleep of those diagnosed with depression affected. There seems to be a striking reduction in stage 3 (SWS).
Describe bipolar disorder and some of the brain changes associated with it.
- bipolar disorder is a psychiatric disorder characterized by periods of depression that alternate with excessive, expansive moods.
- neural basis is not fully understood but people with bipolar disorder exhibit enlarged ventricles on brain scans.
- bipolar disorder seems to have more in common with schizophrenia than with depression.
- lithium often relieves symptoms of bipolar disorder
Define benzodiazepines and anxiolytics and explain how they work in the brain.
Benzodiazepine: any of a class of anti-anxiety drugs that are noncompetitive agents of GABA receptors in the central nervous system.
Anxiolytic: a substance used to reduce anxiety. “Anxiety-dissolving” includes alcohol, opiates, barbiturates, and benzodiazepenes.
GABA receptors are widely distributed throughout the brain, especially in the cerebral cortex and some subcortical areas, such as the hippocampus and amygdala.
Describe post-traumatic stress disorder and the neural changes associated with it.
PTSD is a disorder in which memories of an unpleasant episode repeatedly plague the victim.
People who display combat-related PTSD show:
1. memory changes such as amnesia for some war experiences.
2. flashback
3. difficulty in short-term memory
The volume of right hippocampus smaller in combat veterans with PTSD than those without. Monozygotic twins without PTSD also had a smaller hippocampus.
Hormonal link: PTSD sufferers exhibit a paradoxical long-term reduction in cortisol (stress hormone) levels, perhaps due to increases in sensitivity to cortisol.
Describe OCD and the neurological changes associated with it.
OCD is an anxiety disorder in which the affected individual experiences recurrent unwanted thoughts and engages in repetitive behaviors without reason or ability to stop.
compulsions = acts
obsessions = thoughts
- people with OCD display increased metabolic rates in the orbitofrontal cortex, cingulate, cortex, and caudate nuclei.
- drugs that increase synaptic availability of serotonin might be helpful.
- OCD and Tourette’s comorbid, often involving abnormalities of the basal ganglia.
Describe Tourette’s and the associated neurological deficits.
Tourette’s is a disorder involving heightened sensitivity to sensory stimuli that may be accompanied by verbal or physical tics.
- also usually exhibit OCD or ADHD
- children display thinning of somatosensory and motor cortex. Tics may be mediated by these regions; uninhibited by cortex.
- treatment: halperidol (1st gen antipsychotic; reduces the tic frequency)
- DBS, aimed at thalamus, in regions associated with the control of movement
