Neurobiology of Affective Mood Disorders Flashcards
What is normal mood termed?
Euthymia
Name 3 disorders of mood
Depression
Hypomania
Mania
Name 2 subsyndromal mood disorders
Dysthymia
Cyclothymia
What is cyclothymia?
Patient’s mood goes up and down between subsyndromal increased mood and subsyndromal decreased mood
Is dysthymia more prevalent in M or F?
F (1:2)
Are depressive orders more prevalent in M or F?
F (1:2 approx)
What is the average age of onset of depressive orders?
Mid 20s, with modest peak between 40-60
Is bipolar disorder more prevalent in M or F?
Equal prevalence 1:1
When is the average of onset for BPD?
Ave = 18, normally before 25
What is the term for chronic low (subsyndromal) mood?
Dysthymia
What are Ps who have had one depressive episode at risk of?
Having subsequent periods of depression
How long can untreated and treated depressive episodes last for?
Untreated (> 6months) - can last years
Treated - 2-3 months
What percentage of Ps who have had a depressive episode with go on to have a further episode?
80%
What are the main features of a depressive episode?
Low mood, dec energy & anhedonia
Also - dec activity, changes in appetite, sleep, dec libido, conc/attention, self-esteem & feelings of guilt/worthlessness
What is the requirement for symptoms in terms of duration etc to diagnose for depression?
Most of the time for most days for longer than 2 weeks
+
Reduced social / occupational function
+ NOT in the context of a major life event
What disorder can depression in the context of a major life adjustment be?
Adjustment disorder
What are the three main features of depression?
Low mood
Reduced energy levels
Andhedonia
What are the biological features of depression?
Appetite (red or inc)
Sleep (problems)
Libido (loss)
Activity (slowing)
What are the psychological features of depression?
Cognition (poor conc / attention)
Low self-esteem
Negative thinking
Anxiety
Name three additional features that MAY appear in depressed Ps.
Dissociation
Obsessions
Phobias
Physical health symptoms
What are the psychotic features that may occur in severe depression?
Delusions
Hallucinations
What are obsessions?
Recurrent and persistent thoughts that are intrusive and belong to the P.
Which depression is a severe depression that is characterised by a severe loss of pleasure in almost everything?
Melancholic depression
Which depression can present with increased appetite & weight gain, increased sleep, anxiety, fatigue & prominent interpersonal sensitivity?
Atypical depression
How can depression affect executive function?
Can impair executive function - with reduced concentration and attention –> hard to register information = reduced memory
What is the term for the impact on cognition by dementia?
Cognitive impairment due to depression
What can cognitive impairment due to depression be confused with?
Dementia
How are depression and dementia linked?
Depression is a RF for dementia - x2 inc risk from one episode of depression (and risk increases with multiple episodes).
Depression can be an early sign (prodrome) of dementia.
Depression is also common in Ps with dementia
What do we think causes a link between depression and dementia?
Vascular damage
Hippocampal damage (from chronic high cortisol)
Impaired amyloid clearance (high cortisol)
Chronic inflammation
What are the risks to be aware of for Ps with depression?
Self-harm
Suicide (10%)
Self-neglect
Harm to others
Which physical illnesses can cause mood symptoms?
Brain disease
Endocrine disorders
Infections (inc HIV)
What percentage to Ps attending primary care have depression?
40%
How does physical illness link to depression?
Medical illness can be a stressor that causes depression.
Also - worse outcomes for physical illness in depressed Ps.
Is there a specific gene for depression?
Is there a genetic factor in depression?
Not a specific gene - there are multiple genes that play a role.
Yes - 3x inc risk of developing depression if a 1st degree relative has depression
Which is the strongest theory for the cause of depression?
Monoamine theory
What does the monoamine theory suggest?
Suggests depression is due to an abnormality in one or more monoamine NT systems
What is the precursor of serotonin?
Tryptophan
Which enzyme converts tyrosine to L-DOPA?
Tyrosine hydroxylase
What has been shown when tyrosine hydroxylase is inhibited?
Levels of Dopamine and Nor decrease - and depressive relapses can occur
What are the problems with the monoamine theory?
Why some people respond to type of antidepressant and not another?
Why is there a delayed onset of action when NT level changes are immediately?
How is thought the HPA axis plays a role in depression?
Elevated plasma cortisol levels - which are not inhibiting the HPA axis - leading to impaired cognitive function.
Treatment of HPA has been seen to normalise the HPA axis
Why do we think inflammation plays a role in depression?
Inc levels of depression in Ps with AI
Cytokines therapeutically can trigger depression
Post mortem studies of Ps with depression have found inflammatory signs
Which hormone is linked to neurogenesis?
Brain derived neurotrophic factor (BDNF)
How is BDNF linked to depression?
Low levels of BDNF (and therefore neurogenesis) are seen in Ps with depression
What is the link between monoamines and neurogenesis?
Is postulated that increasing levels of monoamines increases neurogenesis
What are the two types of bipolar disorder? How can you differentiate between them?
Type 1 - P has at least one manic episode (often multiple)
Type 2 - has one hypomanic & one depressive episode (often multiple)
What is the average onset age for depression?
Mid 20s
Mid-life 40-60
When is the average age to be diagnosed for bipolar disorder?
Before 25 (ave = 18)
Which moods do Ps suffer with in bipolar disorder?
All of them - from mania to depression
What is it called when Ps have symptoms of both mania and depression at the same time?
Mixed affective state
What are the clinical features of mania?
Elevated mood
Increased energy
Loss of social inhibition
Pressured speech
Distractibility
Increased self esteem - grandiosity
Perceptual disorder (inc vividness)
Risky behaviour
Which two symptoms of severe mania can overlap with psychosis?
Delusions
Hallucinations
How does hypomania differ from mania?
Similar - however psychotic features are absent, there is NO marked impairment in function (social or occupational) and it does not necessitate hospital admission.
How does the onset of bipolar usually present?
Onset in late teens with a depressive episode
What is more common in bipolar - depressive or manic episodes?
Depressive
How does bipolar affect life expectancy? Why?
Reduces it - by 13 yr M and 9 yr F
Accidents, risky behaviour, self-neglect, suicide
What is the aetiology for bipolar thought to be?
Genetic
Neurobiological
Medication & substances
Childhood adversity
Life events
Which medications can put Ps at a higher rate of developing bipolar?
Corticosteriods
Thyroxine
L-Dopa
Stimulants
Anabolic steriods
Is there a genetic link for bipolar disorder?
Up to 70% is inheritable - is a greater risk if first degree relative, twin concordance studies have been positive.
Thought not to be a single gene - rather hundreds of genes each with small effect
What is more of a statistical risk to developing bipolar disease - schizophrenia or unipolar depresson?
Schizophrenia
Which two NTs have been linked to bipolar disorder?
Dopamine
Glutamate (thought to be inc in Ps with bipolar)
