Anxiety Flashcards
Define anxiety
A feeling of worry, nervousness or unease about something with an uncertain outcome
Symptoms of anxiety
Palpitations Sweating Trembling or shaking Dry mouth Difficulty breathing Chest pain/ discomfort Nausea she/ abdo distress Dizzy, unsteady, faint
What controls the stress response?
Limbic system and lambic-hypothalamic-pituitary adrenal axis
Cortex limbic structures -> hypothalamus -> motor regions and sympathetic Ns
What does the limbic system contain?
Hippocampus - floor of temporal horn of lateral ventricle, subiculum + hippocampus proper + dentate gyrus, involved in memory and expressions of emotion
Amygdala- roof of lateral ventricle, collection of nuclei, inputs of sensory info/ Brainstem/ thalamus/ cortex, outputs to cortex/ Brainstem/ hypothalamus - drive related behaviours and processing associated emotions
Prefrontal cortex & Cingulate gyrus - both modulators effect on processes associated with hypothalamus
Describe the hormonal flight or flight response
Slide 18
What is general adaptation syndrome?
- Alarm reaction - NA from sympathetic nerves - A & NA released from adrenal medulla - cortisol from adrenal cortex
- Resistance - cortisol longer lasting than A , maintenance of stress response
- Exhaustion - prolonged stress -> continued cortisol secretion -> muscle wasting, suppression immune system/ hyperglycaemia
Describe the stress-performance curve (yerke’s -dodson curve)
Too little stress (underload) - inactive- laid back
Optimum -> fatigue
Overload - exhaustion
Burn-out - anxiety/ panic/ anger -> breakdown
Slide 21
List some anxiety disorders
Social phobia
Specific phobias
Generalised anxiety disorder
Panic disorder
OCD
PTSD
Main symptoms of PTSD
Re-experiencing
Feeling worse about yourself/ world
Hyperarousal
Avoidance
What do we know about functions of: amygdala, cingulate cortex and hippocampus in functional neuroimaging in: PTSD, panic disorder, social phobia, specific phobia, GAD ?
Slide 26
How do benzodiazepines work?
GABA is main inhibitory neurotransmitter - decreased in cortex in patients with panic disorders
Benzodiazepines increase GABA transmission so reduce anxiety (binding GABA -> greater entry of chloride ion -> hyperoplarises cell -> more difficult to depolarise & reduced neural excitability)
What effect does serotonin have on anxiety?
Increased levels may stimulate serotonin receptors in hippocampus -> neurorportection, neurogenesis and reduction of anxiety
Treatment of anxiety
SSRIs
CBT
Pregabalin - GABA analogue
Don’t use benzodiazepines long term - short fix e.g. couple of weeks (addictive, lots of withdrawal similar to anxiety symptoms)
What is CBT
Situation (triggers) -> thoughts -> physical reactions/ emotions -> behaviours
Questions each stage
What is an obsession
Thought persists and dominates individuals thinking despite awareness that entirely without purpose or persisted/ dominated their thinking beyond the point of relevance or usefulness - causes great anxiety and guilt
What is a compulsion?
Neutralising ritual
Obsessional motor acts - may result from an obsession leads directly to action or may be mediated by obsessional mental image or fear
Can also have mental compulsions e.g. repeating phrase
Diagnostic criteria for OCD
Obsessions/ compulsions/ both present on most days for a period of at least 2 weeks
Pathophysiology of OCD
Suggested theories:
Re-entry circuits in basal ganglia
Reduced serotonin
Reduced activity in dorsolateral prefrontal cortex/ orbitorfrontal cortex
Increased activity in cingulate cortex
PANDAS - paediatric automimmune neuropsychiatric disorder associated with streptococcal infection
Input (from cortical/ subcortical areas)
-> processing in caudate nucleus and putamen (striatum) -> output (inhibitory projections from Globus pallidus and substantia nigra to thalmus via GABA-ergic neurones) re-entry form output to processing
Treatment of OCD
CBT
Exposure response prevention
High dose SSRI (higher and longer dose)
Augmentation with antipsychotics - clomipramine
Deep Brain stimulation
What is PTSD?
Within 6 months of traumatic event or exceptional severity
Evidence of trauma
Repetitive, intrusive recollection or re-enactment of event in memories, daytime imagery or dreams
Conspicuous emotional detachment, numbing and avoidance of stimuli that might arouse recollection of trauma
Pathophysiology of PTSD
Hyperactivity of amygdala -> exaggerated response to perceived threat
Cortisol inhibits
PTSD have lower than normal levels of cortisol
Treatment of PTSD
CBT
Medical treatment - same as anxiety (SSRIs, GABA analogue)
Eye movement desensitisation and reprocessing (think of memory and follow finger with eyes)
