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What are psychiatric disorders?
- - mental health disorders
- - abnormal patterns of mood, behaviour or thought leading to distress, disability, or risk of harm (to self or others)
- - approx 25% of all people will suffer a psychiatric disorder at some point in their life
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What are most commonpsychiatric disorders?
- - anxiety disorders (lifetime prevalence ~20-25%)- generalised anxiety, phobias, panic disorder, post traumatic stress disorder, obsessive-compulsive disorder
- - mood disorders- depression (LP~5-10%)
- - bipolar disorder (LP~ 1-4%)
- - schizophrenia (LP1%)
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What is an emotion?
- - integrated set of changes in physiological and behavioural function and feeling, that offers survival advantage to the organism
- Stimulus which results in-feelings, behaviour, autonomic function, endocrine function, inflammatory status
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What are the two ways we can categories emotions?
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What are negative emotions?
- - anxiety
- - fear
- - terror
- - frustration
- - anger
- - rage
- - sadness
- - grief
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What are positive emotions?
- - relief
- - pleasure
- - elation
- - joy
- - ecstasy
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Which brain regions are most important to the expression of emotional states
- - hypothalamus- stimulation of this can trigger complex response patterns
- - limbic system (prefrontal cortex and amygdala)
- - diffuse neuromodulatroy systems
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What controls the expressions hypothalamic programs?
higher centres in the brain such as the cortex
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What discovered the functions of the frontal lobe
- gage-where that bar goes through that guys head
- it showed:
- - poorly controlled, emotional behaviour- quick to display angry, aggressive responses
- - consistent with more recent studies of pts with prefrontal cortex damage
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What is the prefrontal cortext regarded as?
- - part of a network of structures referred to as the limbic system
- key components include:
- - prefrpntal lobe
- - rostral temporal lobe
- - hippocampus
- - hypothalamus
- - amygdala
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What does the amygdala do?
- help people interpret emoitions
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What is the amygdala a critical to response?
stimulus- thalamus- angdala (ingerited and learnt emotional memories, critical to repsoning to rapid threats)- hypothalamus (action programes)- integrated behavioural, autonomic and endocrine response
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What does the prefrontal cortex do?
- - modulates the activity of the amygdala center

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What is though to be the link to anxiety disorders and depression?
- abnormalitites in the activity of brain structures in the control of emotions
- cortex, amygdala and thalamic activity is abnormal in depressed pts
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Depression
- - normally preceded by unresolved stress (vulnerability- stress hypothesis of psychiatric disorders)
- - abnormal sleep patterns
- - abnormal diurnal heart rate variability cycles
- - abnormal plateet reactivity
- - abnormal immune function
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The diffuse modulatory transmitter systems are considered to play important- but poorly understood- roles in the control of the limbic system and the prefrontal cortex
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Where and what is the pontine noradrenaline system?
- - locus coeruleus in the pons
- - several different types of antidepressants are assumed to treat depression by altering the activity of this system
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Serotonin system
- - brainstem raphe nuclei
- - most commonly used antidepressants (the SSRIs) are assumed to treat depression by altering the activity of this system
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Midbrain dopamine system
- - origin- substantia nigra and ventral tegmental area
- - currently the focus of great interest with regard to depression and addiction
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Schizophrenia
- - onset typically between 15-25
- - not a single illness. A cluster of illnesses characterised by disturbances in-thoughts, perceptions, emotions, behaviours
- - schizophrenics suffer psychotic episods, where positive symptoms are apparent- confused thinking (everyday thoughts dont join up properly), delusions- (false beliefs, not held by others of the same cultural background), hallucinations- (hear, see, fell, smell or taste something that is not actually there)
- - at other times negative symptoms will predominate- blunted emotional responsiveness, poverty of speech, apathy, social withdrawal
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What brain areas are thought to be involved in schizophrenia?
- - pivotal structures are the prefrontal cortex
- - midbrain dopamine neurons that project into the prefrontal cortex
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What does the prefrontal cortex do?
- modulated dopaminergic input to itself, and limbic system
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Neuro- development hypothesis schizophenia
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