Mood Disorders

Question 1

What does the original theories about the etiology of disorders

Answer 1

that neurotransmitters are the cause by either being upregulated or down regulated and therefore causing the disorder (it is part of the etiology, but not the whole story, it is likely a range of altered neurotransmitters)

Question 2

what type of changes are disorders now linked to and what structures are these changes occurring in

Answer 2

permanent structural and biochemical changes in memory and behaviour systems such as the hippocampus, amygdala, dorsal striatum, and prefrontal cortex.

Question 3

Define depression

Answer 3

a mental disorder with recurrent episodes of decreased energy, attention, and negative mood states. alterations in down regulation of serotonin is thought to be the main factor.

Question 4

What has been used to treat depression

Answer 4

drugs that enhance serotonergic levels called SSRIs
ex. dapoxatine, fluoxetine

Question 5

damage to what specific structure has been linked to depression

Answer 5

damage to the hippocampus
there is a strong relationship between the hippocampus, depression, and stress hormones, as stress hormones are elevated, the hippocampus becomes more vulnerable for damage

Question 6

what levels were increased in hospitalized patients with depression and suicide victims and what does this suggest

Answer 6

corticoids and glucocorticoids which suggest a hyperactive HPA axis

Question 7

What is the HPA axis responsible for in depression

Answer 7

responsible for daily life activities and most important is important in stressful experiences

Question 8

what do glucocorticoids do in depression

Answer 8

they suppress the general functions from the HPA axis and upregulate the availability of energy stores to prepare for stressful situations.

Question 9

How is the HPA axis response regulated

Answer 9

by a negative feedback system. when stressed stress hormones are released and this information gets back to the hippocampus which has glucocorticoid receptors that send signals back to the HPA axis and tells it to shut down when needed.

Question 10

What brain region is most vulnerable to damage from prolonged exposure to glucocorticoids in depression

Answer 10

the hippocampus, mostly from chronic stress (unpredictable chronic stress)

Question 11

Explain how the hippocampus gets damaged from chronic stress

Answer 11

elevated, long and high signal of glucocorticoids due to chronic stress, the hippocampus experiences dysfunction, less negative feedback is sent to the HPA axis so stress continues, further glucocorticoids are released and more hippocampal dysfunction and damage occurs

Question 12

what have been found in depression in terms of neurogenesis (2)

Answer 12

down regulation of neurogenesis has been linked to depression in the adult hippocampus

serotonergic medications are commonly used to treat depression by up regulating neurogenesis in the hippocampus

Question 13

How does the amygdala change with depression

Answer 13

the amygdala becomes more active in depressive patients, more active when specifically responding to negative situations

Question 14

what does the increased influence of the amygdala lead to in depressive patients

Answer 14

an increase in negative attribution bias, meaning that depression takes neutral situations and make they have a bias of making them negative instead

Question 15

define anxiety

Answer 15

mental disorder associated with inappropriate levels of fear and related physiological and behaviour responses by the situation.
(thought to be unable to differentiate between cues, environments, etc that are associated with fear and those that are not)
THEY MAKE GENERALIZATION ABOUT FEAR CAUSING

Question 16

What nt is responsible for anxiety

Answer 16

GABA
which anxiety is treated with benzodiazepine drugs

Question 17

What structures might be weakened in individuals with anxiety

Answer 17

weaking of the systems of the hippocampus and amygdala because they support the ability to differentiate between fear responses
so damage to them would cause the generalizations
(the brainstem could also be associated)

Question 18

What is the main idea that needs to be remembered about anxiety

Answer 18

a loss of amygdala and hippocampal control over brainstem and hypothalamic regions mediates the physiological responses associated with fear and anxiety would increase generalization of fear to unrelated situations

Question 19

how is the balanced memory system altered when having anxiety

Answer 19

amygdala and hippocampus are smaller/have less control while the brainstem nuclei is much larger and gains control

Question 20

evidence that extinction learning is done by _____ for generalized anxiety

Answer 20

ventromedial-prefrontal cortex

Question 21

what is the orbital prefrontal cortex functions (3) in anxiety

Answer 21

1. response control
2. behavioural flexibility
3. contingency (what happens in the future/predictions) evaluation

Question 22

what are the functions of the medial prefrontal cortex (4)

Answer 22

it includes both the infra-limbic and pre-limbic prefrontal cortex
1. extinction learning (most interested in)
2. behavioural flexibility
3. executive functions
4. higher-order attentional processes

Question 23

fear conditioning to context experiment (groups, design)

Answer 23

Groups = lesions or inactivate medial or orbital prefrontal cortex
Design = pre-exposure (to make sure no bias), training (cause painful stimulus in one context and none in the other - 8 days), extinction (no stimulus in either - 10 days)

Question 24

fear conditioning to context experiment (results)

Answer 24

Results = see on 4th day of training that conditioning is already occurring, but not in orbito prefrontal, for this group things are generalized because freezing is occurring equally in both. after more training still same generalized results for orbito. Even after 10 days of extinction, orbito damage still show huge generalization which is crazy because so much time has passed.
preference test = orbito damage can still show preference however, so they show learning and understanding but have problems controlling their physiological effects of anxiety to not generalize

Question 25

Conclusions of fear conditioning to context experiment

Answer 25

rats with orbital prefrontal cortex lesions show elevated and generalized fear responses.
preference test shows that this is not due to inability to discriminate the different contexts.
dont show normal extinction.

Question 26

GAD (generalized anxiety disorder)

Answer 26

emotional response patterns become generalized due to inability to constrain them to appropriate cues and contexts

Question 27

researches conclude that anxiety disorders are linked to what structural alterations

Answer 27

prefrontal cortex (orbito and medial), hippocampus, or amygdala
found that orbital frontal cortex play central role in expression of GAD

Question 28

Define OCD

Answer 28

characterized by re-occurring obsessions and/or compulsions that disrupt daily functions of the individual

Question 29

Define and explain the difference of obsessions and compulsions

Answer 29

obsessions = incessant intrusive thoughts or impulses
compulsions = repetitive response patterns are thought to occur in response to various obsessions

Question 30

What disorder is embedded in OCD

Answer 30

anxiety, because any attempt by an individual suffering OCD attempting to resist their compulsive behaviours results in high anxiety

Question 31

alterations in the relationships of what structures are at the core cause of OCD

Answer 31

between the dorso-lateral striatum, prefrontal cortex (orbito prefrontal is probably involved), and the amygdala/hippocampus axis
(the habit system of the dorsolateral striatum is important for compulsive behaviours)

Question 32

amygdala/hippocampal dysfunction results in what in OCD

Answer 32

heightened anxiety levels

Question 33

dampening of the prefrontal function can lead to what in OCD

Answer 33

reduction in inhibitory control of thoughts and behaviours

Question 34

What structure increases dominance in OCD

Answer 34

dorso-lateral striatum (habit system), responsible for compulsions