Anxiety

Question 1

Human fear response

Answer 1

Anxiety is a normal human fear response

• Autonomic reflexes
• Increased arousal/ alertness
• Corticosteroid secretion
• Negative emotions

Question 2

Pathological anxiety

Answer 2

Anxiety becomes pathological when it becomes unfocused and occurs independently of external events

Can be due to specific phobias or generalised

Question 3

Generalised anxiety disorder

Answer 3

GAD involves excessive and difficult to control anxiety about several different events or activities

Has a basis in the pre-frontal cortex (planning) and the amygdala (basic fear circuit)

GABA dysfunction is often seen

Question 4

PTSD

Answer 4

PTSD results in anxiety caused by the recall of stressful events

The individual then re-experiences the trauma

Linked to decreased hippocampus activity

Question 5

Panic disorder

Answer 5

Characterised by sudden attacks of overwhelming fear

Associated with the adrenergic system and involves the amygdala and hippocampus

Question 6

Obsessive compulsive disorder

Answer 6

Obsessions = continually preoccupy the mind, increasing anxiety 
Compulsions = repetitive behaviours that are carried out in an attempt to reduce the anxiety 

Has a basis in the cortex and basal ganglia

Question 7

Phobias

Answer 7

Phobias can be specific or simple

Specific phobias = specific to a single stimulus, develop during childhood and improve with age

Complex phobias= encompass a range of stimuli and develop during adulthood

Question 8

GABA dysfunction

Answer 8

GAD patients are seen to have decreased GABA(A) function in the brain

Theories:

• GABA(A) receptor is downregulated
• An endogenous anxiogenic is acting as an inverse agonist

Leads to a lack of hyperpolarisation, meaning that the brain can be easily overstimulated

Question 9

GABA(A) structure

Answer 9

GABA(A) is a pentamer

-a1, a2, B1, B2, y2

GABA activates the GABA(A) receptor by binding between the a2 and B2 subunits to open a chloride ion channel

The influx of chloride ions then hyperpolarises the cell

Question 10

Benzodiazepines

Answer 10

BDZ binds between the a2 and y2 subunits on the GABA(A) receptor

• BDZ increases the affinity of the receptor for GABA, enhancing the opening of the chloride channel
• This hyperpolarises the cell, helping to reduce overstimulation

Question 11

Side effects of BDZ

Answer 11

BDZ drugs are mostly non-specific

-drowsiness, confusion, amnesia, addictive effects

Question 12

SSRIs

Answer 12

5-HT is also implicated in anxiety

SSRIs can be used to increase the level of 5-HT in the synapse and treat anxiety

-SERT inhibition

Question 13

Buspirone

Answer 13

Buspirone is a 5-HT(1A) partial agonist and a D2 antagonist

-5-HT(1A) is an autoreceptor and so agonism increases 5-HT release

Has a slow onset and typically prescribed with BDZ

Question 14

Insomnia

Answer 14

Described as difficulty falling asleep and staying asleep

Question 15

Sedatives

Answer 15

Decrease moderate brain activity to have a calming effect

Do not induce sleep but help to reduce underlying anxiety

Question 16

Hypnotics

Answer 16

Induce drowsiness to facilitate a sleep resembling natural sleep

Decrease the amount of time spent in REM sleep which may increase anxiety during wakefulness

Question 17

Z-drugs

Answer 17

Bind to GABA(A) receptor between the a2 and y2 subunits

Specific to a particular type of GABA(A) receptor

Facilitate onset of sleep and increase duration of sleep

Decrease the amount of time spent in REM sleep