Mood disorders Flashcards
What are the two broad classes of mood disorders?
- Depressive disorders
- Bipolar disorders
What needs to have happened in order to make a diagnosis of depression?
- Must have had symptoms for at least 2 weeks
What are the core symptoms of depression?
- Low mood
- Lack of energy
- Lack of enjoyment and interest
What are some other symptoms of depression?
- Suicidal ideation
- Lack of appetite/weight loss
- Pain
- Sleep disturbance
- Severe cases might have psychotic symptoms
What is an 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
What are the symptoms of an adjustment reaction?
- Symptoms develop suddenly after an event
- Symptoms fluctuate
- Time limited
- Energy not low
- No particular pattern to sleep disturbance
- Reduced or increased appetite
What are the clinical features of mania?
- Elevated mood and energy levels with racing thoughts (flight of ideas)
- Decreased need for sleep
- Normal social inhibitions are lost
- Attention cannot be sustained
- Self esteem is inflated, often grandiose
- May have psychotic symptoms
What is hypomania?
- Refers to symptoms that are still clearly manic but don’t necessarily reach full diagnostic criteria for mania
How can we diagnose bipolar disorder?
- Following two episodes of a mood disorder, one of which must be either mania or hypomania
- You can be diagnosed with bipolar without ever having been diagnosed with depression
What is bipolar 1?
- Discrete episodes of mania only or mania and depression
What is bipolar 2?
- Discrete episodes of hypomania or hypomania and depression
What are the physical differentials for depression?
- Hypothyroidism
- B12 deficiency
- Chronic disease
- Substance misuse
- Hypoactive delirium
What are the physical differentials for mania?
- Hyperthyroidism
- Delirium
- Iatrogenic (steroids)
- Infection (e.g. encephalitis, HIV)
- Head injury
- Intoxication (e.g. stimulants)
Which brain regions and circuits are implicated by mood disorders?
- Limbic system
- Frontal love
- Basal ganglia
What are the functions of the limbic system?
- Important functions in emotion, memory and motivation
- Composed of many brain regions
- The main emotion circuit is known as the Papez circuit, containing many structures
What structures are found in the Papez circuit?
- Various cortical areas send input to the
- Hippocampus which projects to the mamillary bodies
- Via the fornix
- The mamillary bodies project to the thalamus and hypothalamus
- Thalamus projects back to cortex
- Hypothalamus projects down to pituitary and autonomics
What is the Papez circuit important for?
- Emotions
- Memory consolidation
Why is the Papez circuit important for memory consolidation?
- Hippocampus is able to induce long term potentiation in the cortex to lay down long term memory
Outline the motor effects and cognitive effects of the frontal lobe?
- Motor
- Language
- Executive functions
- Attention
- Memory
- Mood
- Social and moral reasoning
How is the frontal lobe responsible for 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
What is the function of the basal ganglia?
- In addition to motor functions, the basal ganglia also have important roles in emotion, thought and behaviour
- Changes in basal ganglia volume and activity seen in mood disorders
Which neurotransmitters are thought to be involved in mood disorders?
- Serotonin
- Noradrenaline
Where is serotonin produced?
- In the brainstem (raphe nuclei) and distributed to cortex and limbic system
What is serotonin important for?
- Sleep
- Impulse control
- Appetite
- Mood
What is the evidence for decreased serotonin in depression?
- Drugs that increase serotonin in the brain treat depression
- 5HIAA (a metabolite of serotonin) is low in the CSF of patients with depression
- Tryptophan (a precursor of serotonin) depletion causes depression
Which features do not suggest that decreased serotonin causes depression?
- Despite levels of serotonin rising rapidly following the use of drugs such as SSRIs, symptoms only improve over the course of weeks to months
Where is adrenaline produced?
- In the locus coeruleus of the brainstem and distributed to cortex and limbic system
What is noradrenaline important for?
- Mood
- Arousal
- Memory
What is the evidence for decreased levels of noradrenaline in depression?
- Drugs that increase levels of noradrenaline treat depression
- Patients who have recovered from depression but still have low levels of noradrenaline are at higher risk of relapse
- Post-mortem studies suggest lower levels of noradrenaline in the brains of those with depression
What is the biological treatment for depression?
- Antidepressants
- Selective serotonin reuptake inhibitors are first line
- Consider electroconvulsive therapy for severe or refractory cases
What is the psychological treatment for depression?
- CBT
What is the social treatment for depression?
- Help with social stressors such as isolation and financial worries
What are the biological treatments for mania?
- Antipsychotics
- Mood stabilisers
What are the psychological treatments for mania?
- Unlikely to be helpful in acute phase
- Helpful to educate patients regarding recognising triggers and signs of relapse
What are the social treatments for mania?
- Patients need to be kept safe so that risks to self and others are minimised
- Important to think about implications of mania such as finances etc.
