Chapter 22: Mental Illness Flashcards
What is the hallmark of anxiety disorders?
The inappropriate Stress Response either when a stressor is not present or when it is not immediateley a threat.
What is the Stress Response?
The stress response is the coordinated reaction to threatening stimuli. It is characerised by:
Avoidance Behavior
Increased vigilance and araousal
activation of the sympathetic division of the ANS
Release of cortisol from the adrenal glands
The humoral response to stress is mediated by which axis?
The Hypothalamic-pituitary-adrenal axis
What happens to mice which are genetically engineered to have CRH overexpressed, what happens when CRH is eliminated?
When overexpressed mice do show increased anxiety-like behaviors
When eliminated the yhave less anxiety-like behavior than normal mice
Describe the hypothalamic-pituitary-adrenal axis.
Stress > Paraventricular nucleus of the hypothalamus > release of CRH > travels to anterior pituitary gland > release of ACTH travels through bloodstream to the adrenal gland where it stimulates cortisol release > Cortisol supports body in fight or flight response
Which neurons activate the HPA axis and the Stress response?
The bed nucleus neurons (of the stria terminalis)
What is meant by the expression Push-Pull regulation of the HPA Axis by the amygdala and hippocampus?
The amygdala activation stimulates the HPA axis and the stress response. Hippocampal acitivation on the other hand suppresses the HPA system. because the hippocampus has glucocorticoid receptors that are sensitive to circulating cortisol , it is important in the feedback regulation of the HPA axis in preventing excessive cortisol release
Activation of the cetral nucleus leads to….?
Stress response.
Anxiety disorders have been related to….?
hyperactivity of amygdala
diminished acitivity of hippocampus
elevated acitivity of the prefrontal cortex
What are anxiolytic drugs?
Mediactions that reduce anxiety
The two major classes of drugs currently used in the treatment of anxiety disorders are…?
Benzodiazepines and serotonin-selective reuptake inhibitors
How do Benzodiazepines work?
The bind to a site of GABAa receptor that makes it much more responsive to GABA (the major inhibitory neurotransmitter in the forebrain)
How can the widespread social use of alcohol at least in part be explained ?
Ethanol binds to the GABAa receptor which makes it more responsive to GABA > this has anxiolytic function
What did a PET Study show relating people with panic disorder and benzodiapine binding sites?
The number of benzodiapine binding sites was reduced in regions of the frontal cortex that show hyperactive responsiveness during anxiety
Of what is depression a consequence according to the monoamine hypothesis of mood disorders?
Depression is a consequence of a deficit in one of the diffuse modulatory systems
What is the idea behind the Diathesis-Stress Hypothesis of mood disorders?
According to this idea the HPA axis is the main site where genetic and environmental influences converge to cause mood disorders
What regulates the (hippocampal) number of glucocorticoid receptors?
Genes, Monoamines and early childhood experience.
Name four Treatments for affective disorders.
Electroconvulsive Therapy
Psychotherapy
Antidepressants
Lithium
What is an adverse (bad) effect of electroconvulsive therapy?
Memory Loss (extending back 6 months) Can impair storage of new information
What do all antidepressants have in common?
They all elevate the levels of monoamine neurotransmitters in the brain.
Clinically effective antidepressants dampens the hyperactivity of which system in humans? What could be responsible for this finding?
HPA-System.
Might result form more glucocorticoid receptor expression in the hippocampus, which occurs due tot he long-term elevation of serotonin.
What are positive symptoms of schizophrenia?
Positive Symptoms reflect the presence of abnormal thoughts and behaviors, such as:
Delusions
Hallucinations
Disorganized Speech
Grossly disorganized or catatonic behavior
What are negative symptoms (schizophrenia)?
Negative Symptoms refelct the absence of responses that are normally present. These Symptoms include:
Reduced expression of emotion
Poverty of speech
difficulty in initiating goal-directed behavior
memory impairment
What does the dopamine hypothesis of schizophrenia say?
Psychotic episodes in schizophrenia are triggered specifically by the activation of dopamine receptors
What does the Glutamat Hypothesis of schizophrenia say?
The Disorder reflects a diminished acitivation of NMDA receptors in the brain
