L18 - Anxiety Flashcards
Anxiety
Feeling of worry or unease about something with an uncertain outcome
Symptoms of anxiety
Palpitations Sweating Trembling Dry mouth Difficulty breathing Chest pain and discomfort Nausea or abdominal distress
Stress response
Limbic hypothalamo- pituitary adrenal axis
Cortex stimulates limbic structures
Limbic structures stimulate hypothalamus to release CRH - corticotropin releasing hormone
Stimulates pituitary to release ACTH - adrenocorticotropic hormone
Stimulates adrenal cortex to release cortisol
Limbic system
Hippocampal formation:
- Hippocampus
- Dentate gyrus
- Aspects of the parahippocampal gyrus
Septal area
Amygdala
+/-
prefrontal cortex
Cingulate gyrus
Hippocampus
Occupies floor of temporal horn of lateral ventricle
Three parts:
- subiculum
- hippocampus proper
- dentate gyrus
Involved in memory and expression of emotion
Amygdala
- in the roof of lateral ventricle
- collection of nuclei
- controls drive related emotions and processing of associated of emotions
- can induce fear
- inputs of: > sensory information > brainstem > thalamus > cortex
Outputs:
> cortex
> brainstem
> hypothalamus
Modulation of hypothalamus
Prefrontal cortex
Anterior cingulate gyrus
Hypothalamus
Quickly activates sympathetic nervous system
Gradually activates adrenal cortical system by releasing CRH
HPA axis effects
Involuntary
Increase of energy metabolites
Suppression of immune system
Inhibition of allergic and inflammatory processes
General adaptation syndrome
- Alarm reaction
- NA release from sympathetic nerves
- NA and adrenaline released from adrenal medulla
- cortisol released from the adrenal cortex - Resistance
- cortisol is longer lasting - maintenance of stress response - Exhaustion
- prolonged stress - prolonged cortisol release
- muscle wastage
- suppression of the immune system
- hyperglycaemia
Anxiety disorders
Social phobia Specific phobias Generalised anxiety disorder Panic disorder OCD PTSD
- response is greater than the presenting threat
GABA in panic disorder
GABA - inhibitory neurotransmitter
Decreased in panic disorders
Benzodiazepines
Increase GABA transmission so reduce anxiety
Rapid
[alcohol can also do this]
Selective serotonin reuptake inhibitors
Stimulate serotonin receptors in the hippocampus
Prevent reuptake of serotonin therefore more available
Neuroprotection
Neurogenesis
Reduction of anxiety
Treatment of anxiety disorders
SSRIs
CBT
Pregabalin - GABA analogue
DON’T USE BENZODIAZEPINES LONG TERM
Why aren’t benzodiazepines used long term
Benzodiazepine withdrawal symptoms
Become tolerant
Instant craving
CBT
Situation Thoughts Emotions Behaviour Physical reactions
Obsessions
Thoughts that persist and dominate Awareness that thought has no purpose or not useful Repetitive and unpleasant Patient tries to resist Causes great anxiety and guilt
Compulsions
Obsessional motor acts
Due to obsessional impulse or obsessional mental image or fear
Diagnostic criteria of OCD
Obsessions or compulsions on most days for at least 2 weeks
Epidemiology of OCD
Adolescence or early adulthood
Prevalence - 2%
Childhood OCD more common in boys
Overall male to female 1:1
Tourette’s
Tics
ADHD
OCD
Behavioural problems
OCD re entry circuit
Loop between output and processing
PANDAS
Paediatric autoimmune neuropsychiatric disorder associated with streptococcal infection
- 3-12 yrs old
- sudden onset OCD symptoms or tics after infection of group A beta haemolytic strep
- antibodies cross react with neurones in basal ganglia
- respond to treatment with antibiotics and usual OCD management
Treatment of OCD
CBT
Exposure response prevention - prevent the compulsion in the presence of the thought
High dose SSRI with longer treatment
Antipsychotics - clomipramine (TCA)
PTSD
Within 6 months of a traumatic event of exceptional severity
Repetitive, intrusive recollection or re-enactment of the event in memories
Emotional detachment
Numbing feeling
Avoidance of stimuli
Pathophysiology of PTSD
Hyperactivity of the amygdala
Exaggerated response to perceived threat
Treatment of PTSD
Cortisol (conflicting evidence)
- inhibits traumatic memory retrieval
- controls sympathetic response
Medical treatment - SSRI
CBT
Eye movement desensitisation and reprocessing (EMDR)
