S11) Anxiety Disorders Flashcards
What is the limbic system?
- The limbic system is a set of brain structures located on both sides of the thalamus, immediately beneath the cerebrum
- It supports a variety of functions including emotion, behavior, motivation, long-term memory, and olfaction
Identify the components of the limbic system
- Hippocampal formation
- Septal area
- Amygdala
- ± Prefrontal cortex
- ± Cingulate gyrus
Briefly outline the functioning of the limbic system
Briefly outline the limbic-hypothalamo- pituitary-adrenal axis
What are the actions of cortisol?
- Increase of energy metabolite levels
- Suppression of immune system
- Inhibition of allergic and inflammatory processes
What are the three components of the general adaptation syndrome?
Which three process occur in the alarm reaction part of general adaptation syndrome?
- NA release from sympathetic nerves
- Adrenaline and NA release from adrenal medulla
- Cortisol release from adrenal cortex
What occurs in the resistance part of general adaption syndrome?
Resistance – action of cortisol is longer lasting than adrenaline, allows maintenance of response to stress
What occurs in the exhaustion part of general adaptation syndrome?
Exhaustion – prolonged stress causes continued cortisol secretion, leading to muscle wastage, suppression of immune system and hyperglycaemia
What is anxiety?
Anxiety is a feeling of worry, nervousness or unease about something with an uncertain outcome
What are the symptoms of anxiety?
- Palpitations
- Sweating
- Trembling
- Difficulty breathing
- Chest pain
Identify six different types of anxiety disorders
- Social phobia
- Specific phobias
- Generalised anxiety disorder
- Panic disorder
- Obsessive compulsive disorder (OCD)
- Post-traumatic stress disorder (PTSD)
In terms of the functional neuro-imaging, explain the effect of common anxiety disorders on the following parts of the brain:
- Amygdala
- Cingulate cortex
- Hippocampus
- (+) Increased function
- (-) Decreased function
- (-/+) Both increased and decreased function
- (?) Too little information
Explain the relationship between GABA levels and anxiety (and the treatment of such)
- GABA levels are decreased in cortex in patients with panic disorder
- Benzodiazepines increase GABA transmission so reduce anxiety
Explain the relationship between serotonin levels and anxiety (and the treatment of such)
- Increased levels of serotonin (due to SSRIs) may stimulate serotonin receptors in hippocampus
- Leads to neuroprotection, neurogenesis and reduction of anxiety
Benzodiazepines should not be used in the long-term of anxiety disorders.
In light of this, discuss other treatment options
- SSRIs (mainstay) / pregabalin (GABA analogue)
- Cognitive behavioural therapy
Briefly illustrate the steps involved in cognitive behavioural therapy
What is an obsession?
An obsession is a thought that persists and dominates an individual’s thinking despite their awareness that the thought is either entirely without purpose, or has persisted and dominated their thinking beyond the point of relevance or usefulness
What is a compulsion?
A compulsion is an obsessional motor acts which may result from an obsessional impulse that leads directly to the action, or they may be mediated by an obsessional mental image or fear
E.g. I need to turn the light switch on and off ten times or my family will die
Obsessions and compulsions share some features.
Describe four of them
- Originate in the mind of the patient
- Repetitive and unpleasant
- Acknowledged as excessive or unreasonable
- Patient tries to resist, but at least one obsession/compulsion is unsuccessfully resisted
What is the diagnostic criteria for obsessions / compulsions?
- Carrying out the obsessive thought/act is not pleasurable
- Obsessions/compulsions must cause distress / interfere with the patient’s social or individual functioning
- Obsessions and/or compulsions present on most days for a period of at least 2 weeks
Identify three suggested theories for the pathophysiology of OCD
- Re-entry circuits in basal ganglia
- Reduced serotonin
- PANDAS
In terms of the following layout, illustrate how the pathophysiology of OCD might be due to re-entry circuits in the basal ganglia
What is PANDAS?
Paediatric autoimmune neuropsychiatric disorder associated with streptococcal infection is a hypothesis that children develop OCD / tic disorders due to group A beta-hemolytic streptococcal infections
