Exam 4 - Anxiety disorders Flashcards
What areas of the brain are important in fear responses?
amygdala, hypothalamus, thalamus and several areas in the cortex
- damage to the amygdala disrupts ability to process fear
What are the frontal areas (amygdala) of the brain involved in?
inhibition of fear response
What is the cingulate involved in?
subjective feeling and awareness
How do fear and anxiety differ?
- fear is caused by an immediate stimulus and triggers fight or flight reaction
- anxiety does not require a stimulus
GAD
- worried about anything and everything
- excessive anxiety and worry occurring more days than not for at least six months
- clinically significant distress or impairment in social or occupational functioning
Pathology of GAD
- doesn’t appear to be heritable
- GABA, serotonin, and norepi implicated
- inhibitory effect on amygdala, hypothalamus, thalamus and several areas in the cortex
What test is used to measure anxiety in animals?
elevated plus maze
What is the 3 component model of anxiety?
potential stressors -> bodily effects or upsetting thoughts -> bodily effects or upsetting thoughts -> ineffective behavior -> bodily effects or upsetting thoughts
Phobic disorders
persistent, excessive fear and avoidance of specific objs, activities, or situations
- recognizes fear is irrational but cannot prevent it
- social anxiety disorder is a form of a phobia
How could someone develop a phobia?
- learned, there may be a predisposition, or it may be due to temperament
Panic disorder
- repeated and unexpected occurrence of panic attacks and at least one month of persistent worry about having other attacks
- heart palpitations, sweating, trembling, chest pain, depersonalization, and SOB
Who is more likely to be diagnosed with panic disorder?
women
PTSD
- re-experiencing a traumatic event
- involved avoiding and hyperarousal, catastrophic thinking
- hypervigilance, inability to sleep
What is the course of PTSD
?
- most people suffer symptoms in initial weeks after trauma, but most recover in the next 3 months
Acute stress disorder
used to identify those who wont experience a transient reaction but go onto developing chronic PTSD
Pathology of PTSD
- stress causes profound changes in brain that regulate fear and anxiety:
- decrease in hippocampus, prefrontal cortex volume
- increase in dendritic density and activity in the amygdala
OCD
- recurrent unwanted thoughts (obsessions) and repetitive behaviors (compulsions)
What is the diagnostic criteria for OCD?
- either obsessions or compulsions
- person recognizes thoughts and behaviors as excessive and unreasonable
- obsessions and compulsions cause marked distress
- Yale-Brown OCD scale
Pathology of OCD
- has the clearest connection to abnormal neuroanatomy and function
- involves neural dysfunction between the orbitofrontal cortex, cingulate gyrus, caudate nucleus, globus pallidus, and the thalamus
What are the other two animal models of anxiety other than the elevated plus maze?
- light-dark crossing test and water-lick suppression test
What are the pharmacological treatments of panic disorders and GADS?
- GABA agonists (inhibitory NT)
- barbiturates (CNS depressants)
- benzodiazepines
What is the MOA of barbiturates?
- bind to a subtype of receptor on the GABAa receptor called the barbiturate site
- act to facilitate GABA binding and chlorine influx
What are the side effects of barbiturates?
- similar to alcohol intoxication: confusion, impaired judgement, retarded reflexes, loss of muscle coordination, impaired speech
- disrupt REM
- tolerance and dependence occur rapidly
MOA of benzodiazepines
- alter shape of GABAa receptor
- do not open chloride channel
Pharmacokinetics of benzos
- concentrations peak in an hour
- metabolized into active metabolites that will continue to be active
Side effects of benzos
- lethal if combines with alcohol or another GABA agonist
- sedation, cognitive/memory impairments, retarded motor movements, slurred speech
- chronic use for insomnia disrupts REM
3rd Gen anxiolytics
- partial GABA agonists
- serotonin 5-HT1a agonists
- GABAa andn GHB receptor agonists
Drug effects on locus coeruleus firing
- drugs act on the LC, upregulating it
- increases levels of CRF
Pharmacological treatment of OCD
- SSRIs are initially effective in 50-60% of pts
