Introduction to psychiatric disorders

Question 1

What are the 2 key characteristics of schizophrenia?

Answer 1

Hallucinations and delusions (positive symptoms)

Question 2

What is a hallucination?

Answer 2

Perception in the absence of an external stimulus that has qualities of a real perception
Auditory hallucinations of speech are common in schizophrenia, visual hallucinations are rare

Question 3

What is a delusion?

Answer 3

Belief held with conviction despite evidence to the contrary out of keeping with person’s social and cultural background

Question 4

What are some examples of first rank symptoms?

Answer 4

Delusions
Auditory hallucinations
Thought disorder e.g. withdrawal, broadcasting, insertion
Passivity experiences e.g. ‘made’ feelings, drives, volitional acts, alien penetration

Question 5

What are the ICD-11 criteria for schizophrenia?

Answer 5

A combination of positive and negative symptoms that do not arise as a feature of another mental and behavioural disorder.
Positive symptoms - persistent delusions, hallucinations, disorganised thinking, passivity experiences
Negative symptoms - blunt or flat affect, psychomotor disturbances

Question 6

How does ICD-11 classify unipolar depressive disorder?

Answer 6

Presence or history of one depressive episode where there is no history of prior depressive episodes, or at least 2 depressive episodes separated by at least several months without significant mood disturbance.
There have never been any prior manic, hypomanic or mixed episodes which would indicate BPAD

Question 7

What are the key characteristics of depressive disorder (ICD-11)?

Answer 7

Difficulty concentrating, excessive guilt, hopelessness, recurrent thoughts of suicide, change in appetite or sleep, psychomotor agitation, reduced energy

Question 8

Name some examples of dimensional measures used in depression, psychosis and alcohol misuse

Answer 8

Depression severity - MADRS, BDI, 12-item Hamilton
Psychosis - PANSS
Alcohol misuse - AUDIT
The higher the score the more severely ill the patient

Question 9

How are the anterior cingulate cortex and orbitofrontal cortex implicated in psychiatric disorders?

Answer 9

Limbic system linked to motivation - mood disorders, schizophrenia, addictions

Question 10

How are the basal ganglia, including nucleus accumbens, implicated in psychiatric disorders?

Answer 10

Limbic system linked to motivation - mood disorders, schizophrenia, addictions

Question 11

How are the brainstem, including the VTA, PAG and DRN, implicated in psychiatric disorders?

Answer 11

Dopamine and serotonin systems - mood disorders and schizophrenia

Question 12

How is the lateral habenula implicated in psychiatric disorders?

Answer 12

Inhibits brainstem dopamine reward systems, sensitive to aversive stimuli

Question 13

How is the temporal lobe implicated in psychiatric disorders?

Answer 13

Linked to hallucinations, amygdala/hippocampus linked to aversive stimuli - mood disorder

Question 14

How is the dorsolateral prefrontal cortex implicated in psychiatric disorders?

Answer 14

Cognition, planning, executive function (inferior region linked to emotion)

Question 15

How has the anterior cingulate cortex been used in treatment of highly treatment resistant depressive illness?

Answer 15

Anterior cingulotomy within the emotion region but no more posteriorly is associated with long term recovery

Question 16

What is the role of GABA and how is it involved in psychiatric illness?

Answer 16

Inhibits dopamine function in the brainstem

Involved in anxiety and fear

Question 17

What is the role of glutamate and how is it involved in psychiatric illness?

Answer 17

Opponent to GABA i.e. excitatory

Relatively new target for antidepressants

Question 18

How is acetylcholine involved in Alzheimer’s and PD?

Answer 18

Nucleus basalis of Meynert degeneration is seen in AD and PD

Question 19

What is the role of dopamine and how is it involved in psychiatric illness?

Answer 19

Prediction of rewards, motivation and ‘wanting’
Implicated in schizophrenia, addictions
Reduced reward related activity in VTA in depression

Question 20

What is the role of serotonin and how is it involved in psychiatric illness?

Answer 20

Responds to aversive stimuli
Opponent to systems such as dopamine
Target in antidepressants

Question 21

What is the role of opioids and how are they involved in psychiatric illness?

Answer 21

Liking (as opposed to wanting) with mu receptors

Heroin dependency, methadone maintenance

Question 22

What are the 2 dopamine nuclei in the midbrain called?

Answer 22

VTA - ventral tegmental area (limbic projections)

Substantia nigra pars compacta (motor)

Question 23

What are the 3 principal classes of opioid receptor?

Answer 23

Mu - linked to pleasurable experiences, agonist to morphine

Kappa and delta - lot less work to date on imaging these systems in humans

Question 24

Which areas of the brain are involved in the acetylcholine system?

Answer 24

Nucleus basalis of Meynert and brainstem nuclei project widely to rest of brain

Question 25

What does systems neuroscience involve?

Answer 25

Generates models of large scale brain function. These models are tested and refined in humans and animals

Question 26

What are some techniques used to explore neural valuation in humans and animals?

Answer 26

Reinforcement learning and neuroeconomics

Question 27

What is a biomarker and what is its requirements in medicine?

Answer 27

A measurable indicator of some biological state or condition.
Requirements:
objective measurement
good sensitivity and specificity
may or may not be 'mechanism' related