S11) Mood Disorders Flashcards
Mood disorders are also known as ‘affective disorders’.
What does this mean?
affect is another term for mood
Identify the 2 main mood disorders
– Depression
– Bipolar disorder: type 1 and type 2 (includes episodes of mania, one off depression or chronic depression)
In order to diagnose depression, how long should they have the symptoms for?
At least 2 weeks
Patients with depressive disorders usually have the symptoms continually for 2 weeks.
Usually need 2 of 3 core symptoms to be diagnosed with depression?
What are the core symptoms of depression?
- Low mood
- Lack of energy
- Lack of enjoyment and interest (anhedonia)
Apart from the core symptoms, what are other features of depressive disorders?
- Depressive thoughts (hopelessness, helpless, stuck, no future ahead, guilty thoughts even if they have done nothing wrong, suicidal thoughts)
- Somatic/Biological symptoms (loss of appetite/ weight, lack of sleep - initial insomnia, middle insomnia, late insomnia/ early morning wakening, lack of concentration, pain etc)
- In severe cases, may have psychotic symptoms. (often low mood thoughts, depression can be so severe → can be life threatening)
Compare and contrast the difference between a ‘normal’ adjustment reaction and clinical depression in terms of the following:
- Symptom onset
- Energy
- Sleep pattern
- Appetite
- Emotions
Adjustment reaction - e.g. in bereavement: - Adjustment reaction typically occurs after some kind of traumatic event and has fewer somatic features compared to depression. Adjustment reactions do not last as long as depression and tend to have a fluctuating course
– time limited
– symptoms fluctuate (trying to make sense of your loss)
– preoccupation with ‘event’
Depression:
– usually at least 2 weeks
– lack of interest
Look at the following example of a person with severe depression.
What are the features of Mania (seen in bipolar disorders)?
– Elated Mood
– Increased energy
– Pressure of speech
– Decreased need for sleep
– Flight of ideas (lots of ideas in their mind/ racing thoughts)
– Normal social inhibitions are lost (ppl can become promiscuous, have lots of rs they wouldn’t have with ppl, might go to the shops naked)
– Attention cannot be sustained
– Self esteem is inflated, often grandiose
– May have psychotic symptoms (very positive thoughts about themselves, pts who believe they have special powers)
Look at the following example of mania.
What is hypomania?
Hypomania refers to symptoms that are still clearly manic but don’t necessarily reach full diagnostic criteria for mania
What is bipolar affective disorder?
Diagnosis is made following 2 episodes of a mood disorder at least one of which is mania or hypomania.
Therefore you don’t ever have to have a diagnosis of depression to be given the diagnosis bipolar disorder.
Essentially, bipolar disorder is fluctuations in mood.
What is the difference between Bipolar 1 and Bipolar 2?
– Bipolar 1 – discrete episodes of mania only or mania and depression
– Bipolar 2 – discrete episodes of hypomania only or hypomania and depression.
How do the polarity of symptoms of Bipolar disorder vary?
It is really important in psychiatry that you exclude physical causes of psychiatric symptoms.
There are many illnesses that can cause depressive symptoms.
Provide five examples (differentials)
- Hormone disturbance e.g. thyroid dysfunction- hypothyroidism
- Vitamin deficiencies e.g. vitamin B12 deficiency
- Heart and lung diseases
- Blood vessels malfunction
- Kidney disease
- Chronic disease e.g. renal, CVS & liver failure
- Anaemias
- Substance misuse e.g. alcohol, cannabis & stimulants
- Hypoactive delirium
It is really important in psychiatry that you exclude physical causes of psychiatric symptoms.
There are many illnesses that can cause mania like symptoms.
Provide five examples (differentials)
- Iatrogenic e.g. steroid induced
- Hyperthyroidism
- Delirium (hyperactive type)
- Infection e.g. encephalitis, HIV, syphyllis
- Head injury
- Intoxication e.g. stimulants
Identify three brain structures involved in depressive symptoms
- Limbic system
- Frontal lobe
- Basal ganglia
Describe the limbic system (autonomic effects).
→ Important functions in emotion, memory and motivation
→ Composed of many brain regions, however the main emotion circuit is known as the Papez circuit
Describe the structure of the Papez circuit.
Various cortical areas send input to the:
– Hippocampus, which projects to the
– Mammillary bodies
– Via the fornix (white matter, output pathway of the hippocampus)
– The mamillary bodies project to the thalamus and hypothalamus
– The thalamus projects back to the cortex
– The hypothalamus projects down to the pituitary and autonomics mediating some of the somatic effects
– The amygdala is another part of the limbic system, but can be grouped with hippocampus in terms if its connections
Describe the role of the Papez circuit.
– No one really knows how this circuit works, however the output from the hypothalamus is likely to be very important
– This circuit is also responsible for memory consolidation, where the hippocampus is able to induce long term potentiation in the cortex to lay down long term memory.
– We see changes in the size and activity levels of these structures in depression and bipolar disorder
What is the main hypothesis about how mood is determined?
Determined by functional circuits between these brain areas (Limbic system, Frontal lobe, Basal ganglia)
E.g. the frontal lobe projects to parts of the limbic system which in turn connects to the basal ganglia and the brainstem.
This affects:
– Cognitive processed (thoughts)
– Sympathetic output
– Parasympathetic output
– Motor systems
Identify some structures in the limbic system
What are the main functions of the limbic system?
- Emotion
- Motivation
- Memory
What are the possible limbic system changes in mood disorders?
The frontal lobe forms ⅔ of the total cortex- biggest brain lobe.
Identify some functions of the frontal lobe
- Motor function
- Language (Broca’s area)
- Attention
- Memory
- Mood → The inferior portions of the anterior part of the frontal lobe are involved in the
generation and expression of emotions,
probably via connections with the amygdala - Social and moral reasoning
- Executive functions (purposeful goal directed behaviour)
What are the 2 different prefrontal cortex regions and their function?
The ventromedial prefrontal cortex – is thought to be involved in the generation of emotions.
While the orbital prefrontal cortex is thought to be involved in emotional responses – possibly via connection with the amygdala.
What are the possible frontal lobe changes seen in mood disorders?
Identify the general function of basal ganglia functions.
– Motor function; malfunction of the basal ganglia are implicated in neurological illnesses such as:
- Parkinson’s disease
- Wilson’s disease
- Huntington’s disease
– Psychological function:
- Emotion
- Cognition
- Behaviour
Identify some psychological functions of the basal ganglia
- Emotion
- Cognition/ thought
- Behaviour
Changes in basal ganglia volume and activity seen in mood disorders
What are the possible basal ganglia changes in mood disorders?
For depression and mania, describe the several circuits that could account for symptoms.
– Prefrontal cortex: Slowing of thought, executive dysfunction. Altered emotional processing.
– Amgydala: Abnormal emotional processing
– Basal ganglia: Impaired incentive behaviour. Psychomotor changes.
What are the two main neurotransmitters for depressive disorders?
- Noradrenaline (aka norepinephrine)
- Serotonin
Describe the similarity of the neurotransmitters (Serotonin and NA) in mood disorders.
Both are monoamines.
Monoamine hypothesis suggests that depressive disorder is due to abnormality in the availability of these neurotransmitters.
Less evidence re. role of neurotransmitters in mania.
Identify some other neurotransmitters which are important in psychiatric conditions
- Dopamine
- Acetylcholine
- GABA
- Glutamate
What are the functions of noradrenaline in the brain?
- Mood
- Possible role in behaviour (arousal and attention) – fight or flight response
- Implicated in memory functions
Describe the synthesis and transport of noradrenaline
Noradrenaline is made in the locus coeruleus in the brainstem and transported to several areas of the cortex
Describe the relation of NA and depression.
NA thought to be decreased in depression:
– Antidepressants (e.g. SNRI’s, NARI’s and some TCA’s) that increase NA successfully treat depression. (drugs that increase levels of NA treat depression)
– Patients who have recovered from depression who show decreased NA
levels, have significantly higher rates of relapse.
– Postmortem studies of depressed patients vs controls (post-mortem studies suggest lower levels of noradrenaline in the brains of those with depression)
Note:
SNRI - serotonin noradrenaline reuptake inhibitor
NARI - noradrenaline reuptake inhibitor
TCA - tricyclic antidepressant
What is the role of serotonin in the brain?
- Sleep
- Impulse control (link with suicide)
- Appetite
- Mood
Describe the synthesis and transport of serotonin
Serotonin is produced in the brain stem (Raphe nuclei) and transported to cortical areas and limbic system
Which three factors cause people to become clinically depressed?
- Predisposing factors
- Precipitating factors
- Perpetuating factors
How is serotonin involved in depression?
Serotonin is thought to be low in depression.
Evidence to support this:
– SSRI’s, SNRI, TCA’s & MAOi’s all successfully treat depression by increasing levels of serotonin in synaptic cleft - drugs that increase serotonin in the brain treat depression.
– 5HIAA (metabolite of serotonin) is low in the CSF of patients with depression (particularly those who have attempted suicide).
– Tryptophan (precursor for serotonin) depletion causes depression
However, not all features of depression are
explained by this hypothesis.
e.g. despite levels of serotonin rising rapidly following the use of drugs such as
selective serotonin reuptake inhibitors,
symptoms only improve over the course of
weeks to months
It might be the case that antidepressants
act to change the levels of other
neurochemicals, maybe even stimulating
neurogenesis in the hippocampus through
growth factors such as brain derived
neurotrophic factor.
What is the treatment of depression?
Think of the biological, psychological, social treatments.
Use the biopsychosocial model
Biological
Antidepressants:
- First line = Selective Serotonin Reuptake inhibitors.
Other options: SNRI’s, TCA’s etc (can give lithium- a strong mood stabilizer + powerful antidepressant - if 2 antidepressants aren’t working enough AKA treatment resistant depression)
Life threatening/treatment resistant: ECT (electroconvulsive therapy - put pt to sleep, give muscle relaxant, then electric charge passed to the brain to induce a short seizure, do it twice a week for up to 6 weeks → done in life threatening severe depression)
Psychological
– First line treatment for depression: CBT (1 to 1 psychotherapy)
Social – Help with e.g. isolation, social stressors (including housing, finances), exercise (get hot and sweaty), encourage them to do things they enjoy/ engage in their hobbies
What is the treatment of bipolar?
Find treatment that balances out their symptoms depending on their phase.
What is the treatment for mania, think biological, psychological and social?
Biological
– First line: antipsychotics (animaniacs)
– Alternatively: mood stabiliser (e.g. lithium, sodium valproate- can’t give to women of childbearing age as it is very teratogenic)
Psychological
– Acutely unlikely to be helpful, longer term – psychoeducation (hard to do it) re. BPAD, triggers and signs of relapse. - helpful to educate pts regarding recognising triggers and signs of relapse.
Social
– Treat in a place of safety (mostly in community)– where risk to self (Severely suicidal - then bring them into hospital) and others is minimal.
Consideration of implications of mania e.g. debts (excessive spending/ finances).
What is the treatment of bipolar depression (bipolar patients between manic episodes)?
biological, psychological and social
Biological
– Can use antidepressant – but ONLY with mood stabiliser cover.
(if you just given an antidepressant to someone who is depressed that has bipolar disorder → you will send them high, you must always ask if they have had a manic disorder before, therefore you can’t just give an antidepressant)
- ECT
- Lithium
Psychological
– CBT
Social
– as for unipolar depression e.g. exercise
How can we maintain stability in bipolar disorder ( so people that are now well)?
biological, psychological, social
Biological
– Mood stabilisers e.g. lithium, sodium valproate
– +/- Antipsychotic (used as a mood stabiliser e.g. Quetiapine)
Psychological
– Psychoeducation re. bipolar affective disorder.
– CBT – to help prevent relapses
Social
– Consideration of BPAD on employment e.g. shift work. / consider effects on employment etc.
Involvement of family (family support), education of family etc., manage stress as it is a risk factor, keep sleep diaries - as when you become manic, sleep deteriorates over a time period .: it is a good indicator, monitor moods
Identify some predisposing factors of depression
- Genetic
- Childhood experiences
- Female gender
Identify some childhood experiences causing depression
Causation is cumulative:
- Quality of attachment
- Quality of parental relationships
- Loss of a parent
- Bullying
In research woman are consistently found to be more likely to suffer from an affective disorder.
What are the possible reasons for this?
- Social and occupational role (marriage, child care)
- Men are more likely to distract themselves from depressed mood
- Woman are more willing to admit to being depressed
Social stressors are identified as a perpetuating cause for depression.
Provide some examples of this
- Social economic status
- Unemployment
- Financial hardship
- Isolation from family and friends
Central to the available treatments is that the function of the brain is restored.
How can depression be treated?
- Medication – direct effect on the biochemistry of the brain
- Social and psychological interventions e.g. CBT – measurable effect on the biochemistry of the brain
Illustrate the relationship between the aetiology and treatment of depression
