Lecture 21 - Anxiety Flashcards
What is anxiety and is it normal?
Normal
Usually a trigger for it mediated by sympathetics (fight or flight response) proportional to the situation
Which system mediates the stress/anxiety response?
Limbic system
What are the neural parts to the stress response (limbic system)?
Hippocampus
Amygdala
Prefrontal cortex (not classically part of limbic system but definitely in emotion)
How is the hippocampus involved in the stress response??
Receives input from parts of the cortex, this projects to the thalamus and so back to the cortex and also the hypothalamus
Hypothalamus sends signals to autonomic Preganglionics leading to sympathetic nervous system activation and adrenaline release
What is the amygdalas role in the anxiety stress response?
Sits near tip of hippocampus
Receives inputs from sensory system and outputs to cortex and hypothalamus
What is the role of the prefrontal cortex in anxiety?
Suppresses/modulates features of anxiety
What axis is responsible for mediating the stress repsonse?
HPA (hypothalamic pituitary adrenal axis)
What is the hormonal process occurring in the stress response?
Sympathetic activation leads to the Hypothalmus making CRH (Corticotropin-releasing hormone)
CRH leads to ACTH (Adrenocorticotropic hormone) being released which stimulates the adrenal cortex to releases Cortisol
What part of the adrenal cortex releases cortisol??
Zona fasiculata
When does anxiety become a problem?
When repsonse is to a perceived threat not actual threats
Symptoms and psychological response/arousal remains
What are the stage so chronic stress?
Release of adrenaline and cortisol as well as sympathetic activation
Resistance (Andrenaline wears off) chronic stress response but Prolonged cortisols secretion
Exhaustion (chronic side effects of prolonged cortisol secretion)
How can chronic stress causes sensitatsion of the HPA axis?
Dampens down negative feedback pathways of cortisol inhibiting CRH relase
Enhanced positive drive through amygdala increasing actiivty in paraventtrriucalr nucleus of hypothalamus
Inc activity in autonomic nervous system
What is stress habituation?
When repeated mild stress exposure leads to reduced repsonse in the HPA axis so can reduce activity seen in ANS
What are the symptoms of anxiety (pathological stress response)?
Sympathetic activation:
Palpitations
Sweating
Trembling or shaking
Dry mouth
Difficulty breathing
Nausea
Dizzy
Chest pain
What is generalised anxiety disorder (GAD)?
Autonomic overactivity for most days for several weeks for several months
What are thee symptoms of generalised anxiety disorder (GAD)?
Poor concentration
Irritability
Anxious thoughts
Fearful anticipation
Dry mouth, loose stool
Tight chest, difficulty inhaling
Urgency and frequency micturition, ED, menstrual discomfort
Tremor, tinnitus, headache
Insomnia, night terrors
Why can anxiety develop?
Genetics?
Upbringing
Personality type
Maintained stressful life events
How do you diagnose Generalised Anxiety Disroder?
Hx
Examination
Investigations
What are some differentials when it’s actually depression?
Depression
Schizophrenia
Dementia
Substance withdrawal
Thryotoxicosis, Phaeochromocytoma
Ménière’s disease
Paroxysmal tachycardia
How do you treat Generalsied anxiety?
Psychoeductation
Explain
Clear plan
Reduce stressors
SSRIs/SNRIs
Avoid benzodiazepines
Continue treatment after remission to ensure stays in remission
Why are benzodiazepines not recommended for use in patients with anxiety disorders?
Drug needs to be prescribed long term and benzodiazepines lead to:
-tolerance
-dependance
-habituation
What are some examples of SSRIs?
Fluoxetine (Prozac)
Sertraline