Depression Flashcards
What is the DSM?
American Psychiatric Association’s “Diagnostic and Statistical Manual of
Mental Disorders”
What is the Kraepelinian definition of MDI?
ANY recurrent mood episodes of any kind
[depressive OR manic] constituted the diagnosis of MDI
What defines an illness as a mood disorder as supposed to an affective disorder?
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?
Major depressive disorder
What is the prevalence of MDD?
10-20% lifetime rate
What is the difference between sex in depression?
Twice as many woman suffer depression
What is the impact of Mental health numerically?
7% of disability adjusted life years
What is the typical cycle of low mood?
Thoughts - what’s the point?
Feelings - low, flat, irritable
Physiological symptoms - exhaustion
Behaviours - lie in bed all day
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
What are the core symptoms of depression?
Low mood
Low energy
Anhedonia
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 depression?
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 biological symptoms of depression?
Sleep
Libido
Appetite
What are the psychological symptoms of depression?
The world
Oneself
The future
What is a typical cycle of high mood?
Thoughts - I’m the best
Feelings - elation, excitement
Psychological - 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 time frame for diagnosis of mania/bipolar?
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
less than 4 days, or if other specific thresholds are not met for
manic or hypomanic episodes, then
“Unspecified Bipolar Disorder”
When is type II bipolar disorder diagnosed?
only hypomanic episodes are
present, along with at least one major depressive episode, then the DSM-5 diagnosis of
type II bipolar disorder is made
What can manic episodes be characterised by?
psychotic features e.g. delusions/hallucinations
What can hypomania not be diagnosed?
If psychotic features are present
If patient is hospitalised
What is the Bipolar II?
Less elation
Greater depressive episodes
What is cyclothymia
‘mood swings’
not huge either way
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
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
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) (BA 24, 25, and 32)
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?
Preferential recall of negative compared to positive material = one of the
most robust findings in the depression literature
What memory bias is seen in depression?
Bias: Toward 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.
While
amygdala generally is sensitive to detecting and triggering responses to arousing stimuli, it
exhibits a bias towards detecting cues signalling potential threats, like expressions of fear
How has Facial expression recognition modulation
by antidepressants been studied?
Healthy volunteers models
Acute single dose
Neurofunctional: both increased and reduced amygdala response to SSRIs
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?
Depletion via antihypertensive drugs can cause depression
Useful antidepressants increase synaptic monomania cones
Post-mortem evidence of reduced serotonin in those with depression
Blockade of serotonin synthesis by inhibitor prevents antidepressant effects of MAOIs and TCAs
Tryptophan depletion leading to decreased serotonin triggers MDD relapse
How do you measure receptors and transmitters in the brain?
PET
Injection of radio tracer
Tracer binds to specific target
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
