Anxiety Disorders

Question 1

What makes up the stress response?

Answer 1

The limbic system

Limbic-hypothalamo-pit-adrenal axis

Question 2

What is the limbic system?

Answer 2

Set of structures either side of the thalamus: hippocampal formation, septal area, amygdala, prefrontal cortex, cingulate gyrus

Function = emotion, behaviour, motivation, long-term memory, olfaction

Question 3

Describe the hippocampus

Answer 3

Curved piece of cortex = subiculum, hippocampus proper, dentate gyrus

Folded into medial surface of temporal lobe

Floor of temporal horn of lateral ventricle

Function = memory, emotion

Question 4

Describe the amygdala

Answer 4

Buried in roof of lateral venticle

Collection of nuclei

Inputs = sensory info, brainstem, thalamus, cortex

Outputs = cortex, brainstem, hypothalamus

Function = drive related behaviours and processing of associated emotions

Question 5

What is the role of the prefrontal cortex?

Answer 5

Planning complex cognitive behaviour

Personality expression

Decision making

Moderating social behaviour

Modulatory effect on processes associated with the hypothalamus

Question 6

What is the role of the anterior cingulate gyrus?

Answer 6

Location = collar around frontal part of corpus callosum

Reward anticipation, decision making, ethics, morality

Modulatory effect on processes associated with the hypothalamus

Question 7

What are the actions of cortisol?

Answer 7

Increase of energy metabolite levels

Suppression of immune system

Inhibition of allergic and inflammatory processes

Control blood sugar levels

Longer action than adrenaline

Question 8

Define anxiety

Answer 8

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

Question 9

What are the symptoms of anxiety?

Answer 9

Palpitations

Sweating

Trembling or shaking

Dry mouth

Difficulty breathing

Chest pain or discomfort

Nausea or abdominal distress (e.g. butterflies in stomach)

Feeling dizzy, unsteady, faint or light-headed

Question 10

What conditions fall under ‘anxiety disorder’?

Answer 10

Social phobia

Specific phobias: spiders

Generalised anxiety disorder

Panic disorder – discrete episodes

Obsessive compulsive disorder

Post traumatic stress disorder

Question 11

Outline the theories regarding the aetiology of anxiety disorder

Answer 11

GABA (inhib neurotransmitter) levels decreased in cortex

Increased serotonin may stimulate serotonin receptors in hippocampus = neuroprotection, neurogenesis and reduction of anxiety

Question 12

What is used to treat anxiety disorder?

Answer 12

SSRIs = selective serotonin reuptake inhibitors – increase the amount of serotonin in the synaptic cleft

CBT = cognitive behavioural therapy

Pregabalin = GABA analogue

Question 13

Describe an obsession

Answer 13

Thought that persists and dominates despite awareness that the thought is either entirely without purpose or has persisted and dominated beyond the point of relevance or usefulness

Question 14

Describe a compulsion

Answer 14

Obsessional motor act

May be mediated by an obsessional mental image or fear

Question 15

Outline the diagnosis of obsessional/compulsion disorders

Answer 15

Present on most days for a period of at least 2 weeks

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

Question 16

When do obsessional/compulsion disorder usually begin?

Answer 16

adolescence or early adulthood

Question 17

Outline the pathophysiology of OCD

Answer 17

Re-entry circuits in basal ganglia = high activity makes it hard to get rid of excess

Reduced serotonin

Reduced activity in dorsolateral prefrontal cortex, orbitofrontal cortex, cingulate cortex

PANDAS = Paediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infection

Question 18

What are the basal ganglia re-entry circuits?

Answer 18

Normal = INPUT from sub/cortical areas, PROCESSING by caudate nucleus and putamen, OUTPUT by inhib projection from GP and SN to thalamus

OCD = circuit loop from output back to processing that continues around

Question 19

What is Paediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infection?

Answer 19

Sudden onset of OCD post infection with group-A beta-haemolytic strep

Antibodies ‘cross-react’ with neurones in basal ganglia, causing symptoms

Question 20

How is OCD treated?

Answer 20

CBT

Exposure response prevention = not allowing you to carry out your compulsion, breaking the cycle

High dose SSRIs

Antipsychotics

Clomipramine – don’t tend to use due to side effects

Deep brain stimulation – stimulate STN to stim GPi to inhibit thalamus – less stim to the cortex

Question 21

What is post traumatic stress disorder?

Answer 21

Repetitive, intrusive recollection or re-enactment of the event in memories, daytime imagery, or dreams

Conspicuous emotional detachment, numbing of feeling, and avoidance of stimuli that might arouse recollection of the trauma

Question 22

Outline the pathophysiology of PTSD

Answer 22

Hyperactivity of amygdala, causing exaggerated response to perceived threat

Lower cortisol = lower inhibition of traumatic memory retrieval and sympathetic response

Question 23

How is PTSD treated?

Answer 23

SSRIs

CBT

Eye Movement Desensitisation Reprocessing (EMDR) – follow visual stimulus while recounting past events