Depression / Mood Disorders Flashcards
What diagnostic criteria is used to diagnose mood disorders?
DSM-V or ICD-10
When was the biggest change in the DSM?
DSM-III (1980)
DSM before had been the same for around 100 years, with Manic Depressive Illness (MDI) defined as any recurrent mood episodes of any kind (whether you had bipolar or unipolar) - called the Kraepelinian definition
What defines an illness as a mood disorder as supposed to an affective disorder?
Where the fundamental disturbance is a change in affect or mood to depression (with or without associated anxiety) or to elation
Usually accompanied by a change in the overall level of activity
Tend to be recurrent and the onset of
individual episodes can often be related to stressful events or situations
What is MDD?
What is the prevalence of MDD?
What is the prevalence of Bipolar disorder?
Major Depressive Disorder
10-20% lifetime rate
1% lifetime rate for Bipolar-I, 1% lifetime rate for Bipolar-II
What is the difference between sex in depression?
What is the difference between sex in bipolar disorder?
Twice as many woman suffer depression
Bipolar-I = women and men diagnosed around the same Bipolar-II = more women than men
What is the impact of mental and substance abuse disorders on DALYs?
Accounts for 7% of disability adjusted life years
What is the typical cycle of low mood?
Thoughts - What is the point?
Feelings - Low, irritable
Physiological symptoms - Exhaustion, low energy
Behaviours - Lie in bed all day, ruminate
What is the DSM-5 criteria for depressive episode?
Occurrence of 2 weeks or more of depressed mood
AND the presence of 4 of 8 out of the following:
• Sleep alterations (insomnia or hypersomnia)
• Appetite alterations (increased or decreased)
• Diminished interest or anhedonia
• Decreased concentration
• Low energy
• Guilt
• Psychomotor changes (agitation or retardation)
• Suicidal thoughts
When is MDD diagnosed?
If no manic or hypomanic episodes in the past are identified, then the diagnosis of a current major depressive episode leads to a longitudinal diagnosis of Major Depressive Disorder (MDD)
What are the DSM subtypes for MDD?
Atypical features (which represent mainly increased sleep and appetite, along with heightened mood reactivity)
Melancholic features (defined by no mood reactivity, along with marked psychomotor retardation and anhedonia)
Psychotic features (the presence of delusions/hallucinations)
What are the core symptoms of depression?
What are the psychological symptoms of depression?
What are the biological symptoms of depression?
Low mood
Low energy
Anhedonia
The world
Oneself
The future
Sleep
Libido
Appetite
What is the typical cycle of high mood?
Thoughts - I’m the best
Feelings - elation, excitement
Physiological symptoms - increased energy, race sensation
Behaviours - impulsive, increased activity
What are the DSM diagnosis criteria for Mania/Bipolar?
Euphoric or irritable mood with 3 or more of 7 manic criteria:
- Decreased need for sleep with increased energy
- Distractibility
- Grandiosity or inflated self-esteem
- Flight of ideas or racing thoughts
- Increased talkativeness or pressured speech
- Increased goal-directed activities or psychomotor agitation
- Impulsive behaviour (such as sexual impulsivity or spending sprees)
What is the diagnosis criteria for Bipolar-I?
What is the diagnostic criteria for a hypomanic episode?
What is the diagnostic criteria for Bipolar-II?
What is the diagnostic criteria for Unspecified Bipolar Disorder?
Minimum 1 week with notable functional
impairment leading to a DSM-5 diagnosis of type I bipolar disorder
Minimum 4 days, but without notable functional impairment, a hypomanic episode is diagnosed
Only hypomanic episodes present alone with at lead one MD episode = DSM-5 diagnosis of Bipolar-II
Less than 4 days, or if other specific thresholds are not met for manic or hypomanic episodes, then “Unspecified Bipolar Disorder”
What can manic episodes be characterised by?
What can hypomania not be diagnosed?
Psychotic features e.g. delusions/hallucinations
If psychotic features are present and/or if patient is hospitalised
Is bipolar disorder still diagnosed even if it is caused by anti-depressants?
Yes in the DSM-V, was not considered in the DSM-IV
What is illness course for Bipolar-I?
Big mood swings, reaches the thresholds for proper manic and depressive episodes (amplitude of wave is huge in both directions)
What is the Bipolar II?
Less elation for mania
Greater depressive episodes - reaches the same amplitude as Bipolar-I for depression
What is Cyclothymia?
‘mood swings’
Not huge either way
What percentage of patients relapse within a year of recovery from a mood disorder?
50-60%
Patients largely autonomous between episodes
What are the stats for the first episode in bipolar I?
85% have a depressive as first episode
10% a manic episode
3-5% mixed episode
What must not be ignored in people with bipolar disorder?
Anxiety
30-70% of bipolar patients have anxiety
Presence of anxiety leads to worse prognosis and outcomes
What are the similarities between bipolar and unipolar illness?
MDD is also diagnosed young
MDD is also recurrent
Genetics had found frequency occurrence of bipolar illness in relatives of those with unipolar depression
Treatments overlap
Lithium effective in both unipolar and bipolar types
What are the differences between bipolar and unipolar illness?
Bipolar is has higher heritability
Insight is preserved in depression but impaired in mania
Bipolar illness has an earlier age of onset
More frequent episodes in bipolar than unipolar
Shorter depressive episodes in bipolar than unipolar
What are the features of attention bias in depression?
Attention biases more typical of anxiety
Depression is characterised by biases in maintaining/shifting attention =
difficulties for depressed people to disengage from negative material
What imaging is used in depression?
Functional MRI
works by detecting the changes in blood oxygenation and flow that occur in response to neural
activity
What does a fMRI show in depression?
Sustained amygdala response to negative stimuli
Prefrontal cortex:
Perigenual anterior cingulate cortex (ACC) appears to mediate negative attentional biases
Lateral inferior frontal cortex associated with the impaired ability to divert attention from task-irrelevant negative information
What is memory bias?
What memory bias is seen in depression?
Preferential recall of negative compared to positive material
Bias = towards negative material or away from positive material
What perceptual biases are present in those with depression?
Increased recognition of negative faces
AND/OR
Decreased recognition of happy faces
What happens when someone with depression passively views emotional facial expressions?
Enhanced amygdala response to negative faces
What is the amygdala?
Medial temporal lobe region is involved in the perception and encoding of stimuli relevant to current or chronic affective goals, ranging from rewards or punishments to facial expressions of emotion to aversive or pleasant images and films
Is generally sensitive to detecting and triggering responses to arousing stimuli, it exhibits a bias towards detecting cues signalling potential threats, like expressions of fear
What has facial expression recognition modulation by antidepressants shown with acute single doses?
Healthy volunteers models
Acute single dose of:
Noradrenergic antidepressant = better recognition of happy faces
Serotonergic antidepressant = decreased recognition of fearful faces
Neurofunctional: both increased and reduced amygdala response to SSRIs
What has facial expression recognition modulation by antidepressants shown with daily treatment for a week?
Noradrenergic and serotonergic antidepressants = reduced recognition of anger and fear
Neurofunctional = reduced amygdala and medial prefrontal cortex response to fear
All this occurs before changes in subjective mood
What is serotonin?
NT in brain
14 different serotonin receptors
Found all over the brain
What is the ‘monoamine deficiency hypothesis’?
Postulates that depressive symptoms arise from insufficient levels of monoamine neurotransmitters: serotonin (or 5-hydroxytryptamine , 5-HT),
norepinephrine, and/or dopamine
What is serotonin also known as?
5-HT
What is the indirect evidence of 5-HT hypo-function in depression?
5-HT depletion via antihypertensive drugs can cause depression
Useful antidepressants increase synaptic monomania cones
Post-mortem evidence of reduced 5-HT in the brainstem of those who committed suicide
Lower levels of 5-HT1A and 5-HT4 receptors
Increased monoamine oxidase A in MDD
Blockade of serotonin synthesis by inhibitor prevents antidepressant effects of MAOIs and TCAs
Tryptophan depletion leading to decreased serotonin triggers MDD relapse
Monoamine depletion correlates with low mood
How do you measure receptors and transmitters in the brain?
Use of PET scans -
First = injection of radio tracer
Tracer binds to specific target
How does a PET scan differ to fMRIs?
More selective More invasive Radioactive More expensive Less optimal temporal and spatial resolution
What is the issue with measuring the release of cerebral 5-HT?
No suitable tracer has been found
None are sufficiently sensitive to pharmacological challenges
