Session 11 - Lecture 2: Anxiety

Question 1

Define anxiety.

Answer 1

A feeling of worry, nervousness, unease about something with an uncertain outcome.

Question 2

Describe the pathways of the stress response.

Answer 2

Cortex –> limbic structures (hippocampus, amygdala, septal area, prefrontal cortex and cingulate gyrus) –> hypothalamus –> motor regions and sympathetic nervous system.
Cortex –> limbic structures –> hypothalamus –> pituitary gland –> ACTH –> adrenal gland –> cortisol (high energy metabolites, dampened immune system and allergic and inflammatory response).

Question 3

Describe the general adaptation syndrome is.

Answer 3

General adaptation syndrome is a three-stage response that the body has to stress.
Alarm reaction - NA release from adrenal medulla and cortisol release from adrenal cortex.
Resistance - action of cortisol is longer than adrenaline, allows maintenance of response to stress.
Exhaustion - prolonged response due to continued high levels of cortisol secretion (leads to muscle wastage, dampened immune response and hyperglycaemia).

Question 4

Describe the changes of activity in the brain with PTSD.

Answer 4

Amygdala increases in activity, hippocampus can increase or decrease.

Question 5

Describe the changes of activity in the brain with panic disorder.

Answer 5

Amygdala can increase or decrease in activity. Reduced GABA.

Question 6

Describe the changes of activity in the brain with social phobia.

Answer 6

Amygdala increases in activity, cingulate cortex can increase or decrease.

Question 7

Describe the changes of activity in the brain with specific phobia.

Answer 7

Amygdala increases in activity, cingulate cortex can increase or decrease.

Question 8

Describe the changes of activity in the brain with general anxiety disorder.

Answer 8

Amygdala can increase or decrease in activity, cingulate cortex increases in activity.

Question 9

Describe the treatment options available for anxiety.

Answer 9

SSRIs will increase the level of serotonin within the hippocampus which is neuroprotective, fluoxetine is an example.
Pregabalin is a GABA analogue which will increase neuronal GABA levels which is usually reduced in anxiety. Note: do not use benzodiazepines long term.
Cognitive behavioural therapy:
Situation –> thoughts behaviour (emotions + physical reactions).

Question 10

Define obsessions in terms of OCD.

Answer 10

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/usefulness. These thoughts often cause great anxiety and guilt, are repugnant to the individual and can reflect changes in society.

Question 11

Define compulsions in terms of OCD.

Answer 11

Obsessional motor acts, obsessional impulses that leads directly to the action.

Question 12

What are the diagnostic criteria for OCD?

Answer 12

Obsessions/compulsions/both present on most days for a period of at least 2 weeks.
Acknowledged as excessive/unreasonable.
Carrying out said actions are not pleasurable in itself.
Must cause distress/interfere with the patients’ social individual functioning.

Question 13

What are the causes of OCD?

Answer 13

Re-entry circuits in the basal ganglia (from globus pallidus and substantia nigra back to caudate nucleus and putamen striatum).
Reduced serotonin.

Question 14

Describe a specific OCD that is linked to infection of young children.

Answer 14

Paediatric autoimmune neuropsychiatric disorder.
Sudden onset of OCD
Group A beta haemolytic strep (3-12yo)
Antibodies cross react with basal ganglia neurones
Treat with antibiotics

Question 15

Describe the treatment of OCD.

Answer 15

Cognitive behavioural therapy, exposure-response prevention, high dose SSRIs, TCA, deep brain stimulation of STN, GB and SN.

Question 16

Describe PTSD.

Answer 16

Within 6 months of traumatic event of exceptional severity. Repetitive, intrusive recollection or re-enactment of event. Emotional detachment, numbing of feeling, avoidance of stimuli that might arouse recollection of trauma.

Question 17

Describe the pathophysiology of PTSD.

Answer 17

Increased activity of amygdala --> exaggerated response to perceived threat.
Reduced cortisol (usually inhibits traumatic memory retrieval and controls sympathetic response).

Question 18

What are the treatment options available for PTSD?

Answer 18

SSRIs, benzodiazepines (short term), cognitive behavioural therapy, eye movement desensitisation and reprocessing.