Mood disorders

Question 1

Prevalence of MDD

Answer 1

increasing rate of Major depressive disorder (MDD), wth an earlier age of onset

Question 2

Classification of mental disorders

Answer 2

DSM-V (NICE guidelines)
ICD-10 (WHO system)

Question 3

What is the Kraepelinian definition of MDI?

Answer 3

Any recurrent mood episodes of any kind (depressive or manic)

Question 4

Definition of mood disorders ICD-10

Answer 4

Recurrent change in mood/affect to either depression or elation accompanied by a change in overall level of activity

onset related to stressful events

Question 5

What is a depressive episode?

Answer 5

2 weeks or more of a depressive mood, associated with: sleep alterations, change in diet, anhedonia, anergia, low concentration and agitation

Question 6

How would you diagnose Major Depressive Disorder?

Answer 6

Major depressive episode with no manic or hypomanic episodes in the past

Question 7

What are the three groups of features in major depressive disorder?

Answer 7

Atypical (increased sleep, appetite, and mood reactivity) //
Melancholic (anhedonia, blunted affect, decreased mood reactivity and psychomotor retardation) //
Psychotic (delusions/hallucinations)

Question 8

Core symptoms of depression

Answer 8

Low mood
anhedonia
anergia

Question 9

What are the biological symptoms of depression?

Answer 9

sleep
loss of libido
changes in appetite

Question 10

What are the psychological features of depression?

Answer 10

Attitudes towards the world, oneself and about the future

Question 11

What is a manic episode?

Answer 11

Euphoric or irritable mood associated with: less need for sleep, distractibility, inflated self-esteem, impulsivity

Question 12

How would you diagnose Type 1 Bipolar Disorder?

Answer 12

Manic episode for at least 1 week with notable functional impairment

Question 13

What is hypomania?

Answer 13

A milder form of mania - when the symptoms of a manic episode occur for at least 4 days without notable functional impairment (ie psychotic behaviour). It is NOT underactive behaviour

Question 14

How would you diagnose Type 2 Bipolar Disorder?

Answer 14

Hypomanic episodes (no manic episodes), with at least one major depressive episode

Question 15

What is the diagnosis for manic symptoms that occur for less than 4 days?

Answer 15

Unspecified Bipolar Disorder

Question 16

Exceptions to diagnosis of hypomania

Answer 16

Psychotic features
Hospitalised patient

Question 17

What is cyclothymia?

Answer 17

Milder version of bipolar disorder - fluctuating mania and depressive episodes but not as severe amplitude

Question 18

How does Type 1 Bipolar Disorder compare to cyclothymia with changes in mood?

Answer 18

Much more significant amplitudes in fluctuations between manic and depressive episodes

Question 19

How does Type 2 Bipolar Disorder compare to other bipolar disorders with changes in mood?

Answer 19

Similar amplitude of manic episode to cyclothymia // Similar amplitude of depressive episode to Type 1 Bipolar Disorder

Question 20

What will the majority of first episodes in Type 1 Bipolar Disorder be?

Answer 20

Depressive (85%)

Question 21

Differences between bipolar and unipolar conditions.

Answer 21

• Age of onset, (earlier in bipolar)
• Shorter depressive episodes in bipolar
• Recurrent course, (more frequent episodes in bipolar)
• Genetic specificity, (manic episodes seem to run in families)
• Differential treatment, (antidepressants for unipolar depression vs neuroleptics/lithium for mania)

Question 22

Describe the attention biases in depression

Answer 22

Prolonged maintenance of attention over negative material
reduced attention to positive stimuli

Question 23

Describe the memory biases in depression

Answer 23

Preferential recall of negative material compared to positive
Seen in at risk individuals and those who are recovered

Question 24

Describe the perceptual biases in depression

Answer 24

Preferential recognition of negative faces in a line of negative and happy faces

Question 25

What 3 areas of the brain are responsible for this and why?

Answer 25

Sustained amygdala response to negative stimuli // Prefrontal cortex: anterior cingulate cortex (mediates negative attention bias) / lateral inferior frontal cortex (impaired diversion from negative material)

Question 26

Role of the amygdala in perceptual bias

Answer 26

Enhanced amygdala response to negative faces Sensitive to detecting and triggering responses to arousing stimuli e.g. reward/punishment. Bias to detecting cues signalling potential threat such as fearful expression.

Question 27

What is the monoamine deficiency hypothesis?

Answer 27

Depressive symptoms arise from insufficient levels of monoamine neurotransmitters: serotonin (5-HT), norepinephrine, dopamine

Question 27

What are five indirect evidences for depression being caused by 5-HT hypofunction?

Answer 27

Anti-hypertensive drugs causes 5-HT depletion and was associated with depression // Useful antidepressants increase synaptic monoamine concentrations// Post-mortem lower levels of 5-HT in brainstem of those who commited suicide// MDD has elevated monoamine oxidase A// Tryptophan depletion triggers relapse in MDD that has be successfully treated with SSRIs

Question 28

Why is there only indirect evidence that depression occurs from 5-HT hypofunction?

Answer 28

Difficult to measure serotonin levels in the brain

Question 28

What is the main way of quantifying receptors in the living human brain? Aka baseline scan

Answer 28

PET Imaging: inject a radioactive tracer which binds to a specific receptor - proportion of binding leads to stronger images on scan

Question 28

How do we quantify the amount of transmitter in the human brain?

Answer 28

Second PET scan with radio tracer and amphetamine challenge which stimulates NT release. These competitively bind to receptor instead of tracer leading to a weaker image. Subtracting from the baseline scan shows the amount of NT released.

Question 29

Issues with PET radiotracers

Answer 29

5HT antagonists are not sufficiently sensitive to pharmacological challenges 5HT2A agonist works but causes a psychedelic effect

Question 30

Conclusion of radio tracer investigation

Answer 30

Reduced 5HT release capacity in people with depression

Question 31

Tryptamine psychedelics

Answer 31

Psilocybin - 4/5hr oral, 1hr IV DMT - 4/5hr oral, 10/20min smoke/IV LSD - 10/12hr oral, Ihr IV

Question 32

Psychedelic action

Answer 32

Act on serotonin system, similar to 5HT2A agonist Different mechanism to SSRI's

Question 33

What are the effects of psychedelics?

Answer 33

Psychological peaks - spiritual experience, blissful state, deeply positive mood

Question 34

How safe are psychedelics?

Answer 34

Non-addictive, low toxicity, good therapeutic index

Question 35

Adverse effects of psychedelics

Answer 35

Dysphoria, anxiety, headache, nausea

Question 36

Results of phase 2b trial of psychedelics

Answer 36

statistically sig reduction in depression symptoms rapid onset action sustained response at wk 12 .: high durability