12.1 Mood Disorders Flashcards
What are the two major mood disorders?
bipolar - type 1 and 2
Depression
What are the core symptoms of depressive disorders?
Low mood
Low energy
Lack of enjoyment and interest
How long should patients have symptoms for before presenting with depression
2 weeks
Apart from the core symptoms of depression, what other symptoms may patients have?
Depressive thoughts Low self esteem Somatic symptoms / biological symptoms (stop eating and drinking) Weight loss May have psychotic symptoms
What is the difference between a depressive adjustment reaction and depression?
Symptoms develop suddenly after an event vs develop gradually
Symptoms fluctuate vs continuous
Time limited vs usually at least two weeks
preoccupation with the event vs lack of interest
Energy not low vs low energy
No particular disturbance to sleep pattern vs sleep disturbance typically with early morning wakening
Reduced or increased appetite vs loss of appetite and weight loss typical
Feelings of anger and frustration vs low elf esteem and feelings of guilt and blame are typical
What is the symptoms of mania?
- Elated Mood
- Increased energy
- Pressure of speech
- Decreased need for sleep
- Flight of ideas
- Normal social inhibitions are lost
- Attention cannot be sustained
- Self esteem is inflated, often grandiose
- May have psychotic symptoms
When is a diagnosis of bipolar disorder made?
Diagnosis is made following 2 episodes of a mood disorder at least one of which is mania or hypomania.
What is the difference between type 1 and type 2 bipolar disorder?
Bipolar 1 – discrete episodes of mania only or mania and depression
Bipolar 2 – discrete episodes of hypomania or hypomania and depression.
What is euthymia?
Normal mood
How long do bipolar episodes last?
Varies
Depressive episode : 6 to 12 months
Manic episode : 3 to 6 months
What are some of the physical health differentials that could cause depression?
- Hormone disturbance such thyroid dysfunction
- Vitamin deficiencies such as vitamin B12
- Chronic disease e.g. renal, CVS & liver failure
- Anaemias
- Substance misuse e.g. alcohol, cannabis & stimulants
- Hypoactive delirium
What re some of the physical health differentials that could make patients present with mania?
- Iatrogenic e.g. steroid induced
- Hyperthyroidism
- Delirium
- Infection e.g. encephalitis, HIV, syphyllis
- Head injury
- (intoxication with stimulants)
Which brain structures are involved in mood disorders?
Limbic system
Frontal lobe
Basal ganglia
What is the main hypothesis for how mood is determined?
The main hypothesis is that mood is determined by functional circuits between these brain areas. E.g. the frontal lobe projects to parts of the limbic system which in turn connects to the basal ganglia and the brainstem.
What systems does mood affect?
Cognitive processes (thoughts)
Sympathetic output
Parasyumpathetic output
Motor systems
What are the main functions of the limbic system?
Emotion
Motivation
Memory
What limbic system changes are seen in unipolar depression?
Decreased hippocampal volume (in patients with recurrent depressive disorder) Decreased cerebral blood flow and metabolism in the amygdala
What are the possible limbic system changes seen in bipolar affective disorder?
Altered amygdala volume
Increased amygdala activation & volume in mania
Decreases in volume in anterior paralimbic cortices (inc ventral prefrontal cortex, insular cortex and temporopolar cortex) & activation
What are the functions of the frontal lobe?
- Motor function
- Language (Broca’s area)
- Executive functions (purposeful goal directed behaviours)
- Attention
- Memory
- Mood
- Social and moral reasoning
What is the function of the ventromedial prefrontal cortex?
Generation of emotions
What is the function of the orbital prefrontal cortex?
Involved in emotional responses
What are possible frontal lobe changes seen in unipolar depression?
Decreased activity (blood flow) in the dorsolateral prefrontal cortex Decreased volume of orbitofrontal prefrontal cortex
What are the posssible frontal lobe changes seen in bipolar affective disorder?
Reduced dorsolateral prefrontal cortex activation
What are the functions of the basal ganglia?
• 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
What basal ganglia changes are seen in patients with unipolar depression?
Decreased basal ganglia volume
Reduced activation between striatum, amygdala and prefrontal cortex
What changes are seen in the basale ganglia in bipolar affective disorder?
Possible functional changes in the striatum
How do changes in brain function relate to the altered mood and presentation of a depressed patient?
• 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 involved in depressive disorders?
Serotonin
Noradrenaline
What is the monoamine hypothesis?
A hypothesis that the two key monoamines serotonin and noradrenalin have an abnormal availability in depressive disorders
Where is serotonin produced and functioning?
Produced in the brain stem (Raphe nuclei) and transported to cortical areas and limbic system
What actions does low levels of serotonin affect ?
- sleep - especially early waking
- impulse control (higher risk of completed suicide)
- poor appetite
- mood
Low levels of serotonin is thought to cause depression, what is the evidence for this?
– SSRI’s, SNRI, TCA’s & MAOi’s all successfully treat depression by increasing levels of serotonin in synaptic cleft
– 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
Where is noradrenalin produced and what is its function?
Produced in the locus coeruleus (pons) and projects to limbic system and the cortex
What are noradrenalin functions within the brain?
Mood
Suggests a role in behaviour (arousal and attention) – fight or flight response
Implicated in memory functions
Noradrenalin is thought to have a role within depression, what is the evidence of this?
– Antidepressants (e.g. SNRI’s, NARI’s and some TCA’s) that increase NA successfully 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 show depressed patients had lower levels of NA
What are the treatment options for depression?
• Biological -
First line = Selective Serotonin Reuptake inhibitors.
Other options: SNRI’s, TCA’s etc
Life threatening/treatment resistant: ECT
• Psychological – First line treatment for depression: CBT
• Social – Help with e.g. isolation, social stressors (including housing, finances)
What is the treatment of mania?
• Biological
First line: antipsychotics (dopamine antagonists)
Alternatively: mood stabiliser
• Psychological
Acutely unlikely to be helpful, longer term – psychoeducation re. BPAD, triggers and signs of relapse.
• Social
Treat in a place of safety – where risk to self and others is
minimal. Consideration of implications of mania e.g. debts
(excessive spending).
What is the treatment of bipolar depression?
- Biological – Can use antidepressant – but ONLY with mood stabiliser cover. ECT Lithium
- Psychological – CBT
- Social – as for unipolar depression
What treatments are used to maintain stability in mood disorders?
• 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.
Involvement of family, education of family etc.
What is the main emotion circuit in the limbic system called?
The Papez circuit
What is contained in the Papez circuit?
o Various cortical areas send input to the
o Hippocampus, which projects to the
o Mammillary bodies
o Via the fornix (white matter, output pathway of the
hippocampus)
o The mamillary bodies project to the thalamus and
hypothalamus
o The thalamus projects back to the cortex
o The hypothalamus projects down to the pituitary and autonomics mediating some of the somatic effects
o The amygdala is another part of the limbic system, but can be grouped with hippocampus in terms if its connections
