Session 11 - anxiety disorders Flashcards
What is anxiety?
- The stress response (causing a feeling of anxiety) enables us to escape from potentially dangerous situations
- it’s a feeling of worry or unease about something with an uncertain outcome, often when you perceive a threat.not an actual threat
- it’t difficult to manage and is synonymous with neurosis
what is the anxiety response mediated by?
- mainly the limbic system that has neural and endocrine targets
- this system communicates with the cortex and the hypothalamus
what is the limbic system made up of and what are functions of each of these parts?
- hippocampus - receive inputs from many parts of the cortex and processes their emotional content. It projects to the thalamus and back to the cortex (papez circuit) and also to the hypothalamus causing autonomic features of emotional response - sympathetic NS activation → release of adrenaline form the adrenal medulla (acute stress response)
- amygdala - sits near the top of the hippocampus. receives many inputs form the sensory system. Major outputs to cortex and hypothalamus. Its involved in behavioural and autonomic emotional responses
- (prefrontal cortex) - modulates emotional responses (eg. consciously suppressing features of anxiety and allows perception of emotion
- (cingulate gyrus)
what are the endocrine and neural elements of the stress response?
- endocrine: limbic system acts on the hypothalamus to stimulate the secretion of stress hormones -via the hypothalamus-pituitary-adrenal axis. Release of cortisol form the adrenal cortex is part of the chronic stress response
- endocrine response causes increased metabolism, immune suppression and inhibition of allergic/inflammatory processes
what is the general adaptation syndrome?
- this is the 3 stages that the body goes through during prolonged exposure to stressors
- 1) alarm reaction
- 2) resistance
- 3) exhaustion
what is the pathophysiology of the stress response?
- mediated by the ANS/adrenal medulla and HPA axis
- stress activates the preganglionic afferent neurones in the spinal cord which projects to other neurones to release NA/Adr
- HPA stimulated by stress, PVN in hypothalamus releases CRH which causes the pituitary to release ACTH which acts on renal medulla to release cortisol
what does chronic stress do to the stress response system?
- it causes sensitisation of this system
- dampening down negative feedback pathways of cortisol →. inhibiting CRH release
- enhance positive drive through the amygdala, increase activating in the PVN of the hypothalamus
- increased activity in the ANS
what is stress habituation?
repeated mild stress exposure leads to a reduced response in the HPA axis involving activity in the PVN which regular, mild. stress can reduce the activity seen in the ANS but the unreal substances responsible aren’t know?
- patient adapts to the stressor and the stress repose becomes less reactive to it
what are some of the different classifications of anxiety disorders?
- specific phobias - eg. spiders, heights
- social phobia- anxiety about being in social situation
- panic disorder - recurrent unexpected panic attacks (severe episodes fo acute stress response)
- obsessional disorder
- PTSD
- generalised anxiety disorder - persistent anxiety about a variety of things
- each of these disorders have one identifying feature as a lot of the symptoms overlap
what is the pathophysiology of anxiety disorders?
- unclear
- GABA (inhibitory neurotransmitter) levels appear to be low in some anxiety disorders
- increasing serotonin levels can help treat anxiety disorders
- hippocampus potentially involved?
what is the definition of phobias?
- involuntary, perceived as irrational
- causes avoidance
what is the pathophysiology of phobias?
classical condition
what do you assess when diagnosing phobias?
- history, examination, investigation
- rule our a physical disorder and substance abuse
- consider the use of medication for concomitant conditions
treatment for phobias?
- guided self help/CBT
- systematic desensitisation - relaxation, hierarchy
what is agoraphobia, how is the anxiety reduced and what are some common triggers?
- the fear of crowds, open spaces, difficulty to get home/travel
- experience anticipatory anxiety, avoidance, anxious thoughts which maintain the phobia
- anxiety is reduced with support eg if a friend is with them
- common triggers include; distance from home, crowding, open space, social situations
what is the pathophysiology of OCD?
- re-entry circus in the basal ganglia meaning that an output from the basal ganglia keeps being repeated
- reduced serotonin
- PANDAS
(another image on notion)
how do you diagnose and treat OCD?
- diagnosis: history, examination, investigations.
- treat: self help-resist rituals, SSRI(higher dose and longer. treatment course than depression)/clomipramine - continue these fore 6 months after remission (TCA), CBT:
- deep brain stimulation if other methods fail
