Chapter 16: Psychopathology Flashcards
schizophrenia
characterized by negative symptoms (absent but should be present) such as emotional withdrawal and impoverished thought and positive symptoms (should not be present but are) such as hallucinations and delusions
is schizophrenia heritable?
yes, but multiple genes are involved
genes involved in schizophrenia
neuregulin 1
dysbindin
COMT
DISC1
neuregulin 1
regulates NMDA, GABA and ACh receptors
dysbindin
regulates synaptic plasticity
COMT
metabolizes dopamine
DISC1
regulates dendritic spines at glutamate synapses
concordance rate
likelihood if one person in a family has a condition, another member will too
concordance rate of schizophrenia
identical twins: 50%
fraternal twins: 17%
structural changes in brain in those with schizophrenia
- larger cerebral ventricles
- smaller hippocampus and amygdala
- thicker corpus callosum
- insufficient activity of frontal cortex
-abnormal neuronal migration during adolescence - loss of cortical gray matter during adolescence
what happens to patients with larger ventricles?
poorer response to antipsychotics
what causes larger ventricles in rats?
mutated version of DISC1
why are the ventricles larger in those with schizophrenia?
the hippocampus and amygdala help form the walls of the lateral ventricles so the wasting of these regions can lead to ventricular enlargement
what produces psychosis similar to schizophrenia?
amphetamine
antipsychotic medications for schizophrenia
chlorpromazine: dopamine antagonist that blocks amphetamine
- first generation antipsychotic
typical antipsychotics
block D2 receptors
dopamine hypothesis
schizophrenia results from excessive levels of synaptic dopamine or excessive postsynaptic sensitivity to dopamine
what parkinson’s treatment can produce schizophrenia-like symptoms?
L-dopa
hypofrontality hypothesis
schizophrenia comes from insufficient activity in frontal cortex
what do antipsychotics increase?
activation of frontal cortex
glutamate hypothesis
schizophrenia results from insufficient glutamatergic neurotransmission
what NMDA receptor antagonist produces schizophrenia-like symptoms?
phencyclidine (PCP)
risk factors for schizophrenia
people born in a city
pregnant mother had flu in first trimester
mother and baby have incompatible blood types
birth complications leading to oxygen deficiency
depression
unhappy mood, loss of interest, energy and appetite, difficulty in concentration, and restless agitation
who is depression more common in?
women and highest rates around age 40
brain changes with depression
- increased blood flow to frontal cortex and amygdala
- decreased blood flow to areas involving attention and language
- right cortex is thinner
electroconvulsive shock therapy/ (ECT)
causes a seizure by passing an electrical current through the brain
what is the final go to treatment for resistant depression?
electroconvulsive shock therapy (ECT)
transcranial magnetic stimulation (TMS)
under investigation for depression treatment
MAO inhibitors
pharmaceutical treatment for depression that raises the levels of monoamines at the synapse because it stops MAO enzyme from inactivating monoamines
monoamine oxidase (MAO)
enzyme that normally inactivates monamines: norepinephrine, dopamine and seratonin
monoamine hypothesis
depression caused by decreased monoamines at the synapse
tricyclics
blocks the reuptake of monoamines and allows them stay in the synapse longer»_space; activating the synapse for longer
SSRIS
antidepressants that block reuptake of serotonin at synapses
other treatments for depression
vagal nerve stimulation
deep brain stimulation
cognitive behavioral therapy
effectiveness of depression treatments
- CBT and SSRIS: most effective
- CBT alone: 2nd most effective
- SSRIs alone: least effective
why are people with cushing’s disease prone to depression? and what does it suggest?
high levels of glucocorticoids (cortisol: main stress hormone)
it suggests depression may involve issues with HPA axis that releases cortisol
dexamethasone
synthetic glucocorticoid that normally suppresses cortisol release by providing negative feedback to the hypothalamus
dexamethasone suppression test
shows excess cortisol release which can be seen in suicide victims and depressed patients
what individuals can dexamethasone suppress cortisol in?
can suppress cortisol release in normal people but not in depressed people which suggests issues in HPA axis
postpartum depression
immediately after childbirth, points to hormonal contributions in women
how is sleep affected by depression?
time in slow wave sleep is reduced and enter REM sleep quickly
seasonal affective disorder
type of depression brought on by shorter days of winter
learned helplessness
animal exposed to repetitive stressful stimulus caused the animal to eventually stop attempting to escape the stimulus
- linked to decrease in serotonin function
bipolar disorder
periods of depression alternating with expansive mood, or mania
what is rapid cycling for bipolar disorder?
four or more cycles in one year
true or false: some individuals may cycle several times in one day
true
what disorder does bipolar disorder have more in common with?
schizophrenia
structural changes in bipolar disorder
enlarged ventricles
decreased gray matter
cyclothymia
milder form of bipolar disorder with cycles between mild depression and increased energy
lithium for bipolar disorder treatment
mood-stabalizing drug that interacts with circadian rhythm and has a very narrow therapeutic window
what does lithium do?
decrease manic episodes which can cause the desire to stop taking medication
anxiety
includes generalized anxiety disorder and panic disorder
generalized anxiety disorder
persistant, excessive anxiety experienced for months
panic disorder
recurrent transient attacks of fearfulness
characteristics of panic disorder
heart palpitations, rapid breathing, shortness of breath, blurred vision, dizziness and racing thoughts
structural brain changes for anxiety
temporal lobe volumes are reduced or abnormal
lower activity in amygdala
what percent of temporal lobe has lesions in a patient with anxiety?
40%
benzodiazepines
bind to GABA receptors as noncompetitive agonists and makes the membrane more permeable to chloride ions
are SSRIs effective for anxiety?
they can be
phobic disorders
irrational fears that become centered on a specific object, activity, or situation that a person feels compelled to avoid
post-traumatic stress disorder (PTSD)
induced by highly stressful, traumatic event
structural changes with PTSD
lower volume of right hippocampus
learn to avoid stimuli associated with trauma (involves amygdala and brainstem)
failure to forget: hippocampus and prefrontal cortex show weak suppression of amygdala
obsessive compulsive disorder
affected person engages in recurring, repetitive acts that are carried without rhyme, reason, or ability to stop
when does OCD begin?
begins in childhood but peak ages are young adulthood to middle age
what does OCD occur along with?
depression or tourettes
brain structures affected by OCD
orbitofrontal cortex and cingulate cortex (both part of prefrontal cortex)
caudate nuclei (part of striatum)
what does evidence show for OCD?
dysregulated circuit from prefrontal cortex to striatum to thalamus back to cortex
treatment for OCD
cognitive behavioral therapy and prozac
prozac
inhibit reuptake of serotonin at synapse thereby increase serotonin available in synapse
trephination
drill holes in skull
- during roman times
lobotomy
disconnect parts of frontal lobes
- causes personality changes
cingulotomy
lesion pathways in cingulate cortex
- treats depression and OCD
deep brain stimulation
remove portions of epileptic brains thought to cause seizures
