Mood Disorders Flashcards
what is the appetitive network in the brain
the reward system -mediates seeking and approach behaviours (for pleasurable things)
what does the appetitive network involve
ascending dopamine systems mesolimbic/cortico projections dorsal striatum amygdala anterior cingulate orbitofrontal cortex
what does the amygdala do
involved in conditioning/learning
what is the main neurotransmitter in the appetitive network
serotonin
what is the aversive system
system which promotes survival in the event of threat (fear/pain)
what does the averse system involve
Ascending serotonin systems NA/CRF/peptide transmitters central nucleus of amygdala hippocampus hypothalamus periaqueductal grey matter
what is depression
altered sensitivity/accuracy of brain systems evaluating rewards and cues predicting reward within the environment
what is anxiety
altered sensitivity/accuracy of brain systems evaluating threat and cues predicting threat in the environment
why are mood disorders recurrant
- abnormal brain development
- genetic component
- endocrine/metabolic causes
- adverse life effects
- psychological resilience/lack of
- cultural aspects
which neurotransmitters are deficient in depression
serotonin
noradrenaline
dopamine
GABA
neurotransmitters in excess in depression
Acetylcholine
Substance P
Corticotrophin. releasing hormone (stress hormone)
what pathways become v acivite in stressful situations
pathway linking amygdala and cortex
what happens to serotonin in depression
low serotonin causes decrease in binding to receptors in the cortex
also reduction in reuptake sites due to low serotonin
what happens noradrenaline in depression
decrease neurotransmission leading to anergia, anhedonia and decreased libido
what happens to dopamine in depression
hypoactive D1 receptor increases binding of D2/D3 receptors in striatal regions
what happens to GABA in depression
reduction in GABA in plasma and CSF
GABA unregulated by antidepressants
GABA makes you feel relaxed, reduction = stress feeling
what happens to the hypothalamic pituitary axis in depression
HPA is unregulated with a down regulation of its negative feedback controls
Corticotrophin releasing factor is secreted from the hypothalamus, this induces adrenocorticotrophin hormone (ACTH) from pituitary
ACTH causes release of cortisol from adrenal glands
this has a number of effects including elevation of blood glucose and negative feedback to HPA
true or false, serotonin function is abnormal before, during and after episodes of depression
true
what happens to noradrenaline in epilepsy
decrease/deficiency
vulnerable depressed individuals feel v stressed in non-stressful situations which depletes noradrenaline stores
what causes loss of pleasure/interest in depression
hypo function of the dopamine system
what happens to neurotransmitters in mania
also decrease in serotonin
GABA deficit
