Anxiety, PTSD and OCD Flashcards
First stage of anxiety
Alarm Reaction
- HPA: hypothalamus–>CRH/CRF–>anterior pituitary–>ACTH–>Blood–>adrenal cortex–>Cortisol
- Fight or flight: hypothalamus–>sympathetic NS–>spinal nerves–>adrenal medulla–>NE and Epi
Second stage of anxiety if it is a single stressor
Adaptation Stage
-brings body back to normal after single stressor
Second stage of anxiety if you have chronic stress
Resistance Stage
- Continuous secretion of GCs leads to the mobilization of lipids and amino acid reserves to obtain energy. Liver synth glucose to inc blood glucose level
- Continuous secretion of MCs causes a conservation of salts and water (loss of K+ and H+)
Final stage of anxiety
Exhaustion Stage
- reaction to prolonged and frequently repeated stress
- Vital systems collapse due to exhaustion of lipid reserves, inability to continue to produce GCs, failure of electrolyte balance, cumulative damage to organs–>inc risk of disease
What is fear extinction?
Learning not to fear by presenting the CS without the US. This is new learning, not forgetting
What are the two pathways to conditioning
- Involves cortex (indirect)
- Important for differential conditioning, is longer and slower
- Sensory–>thalamus–>cortex–>amygdala etc - Does not involve cortex (direct/low-road)
- No conscious processing, allows for immediate reaction
- Less information capacity
- Fear provoking stimuli go this way for immediate reaction
Inputs both converge in lateral nucleus
What is the hippocampus important for in fear learning?
Contextual processing!
What is the amygdala important for in fear learning?
Both cued and contextual fear acquisition
What part of the brain is important for fear extinction?
Cortex: inhibits expression of fear learning and may modulate amygdala outputs
What reinforces extinction as active learning?
The NMDA receptors do. So if you block them in the amygdala, you interfere with extinction
What is Papez Circuit’s role in fear? Be specific about the cingulate cortex
Emotional representations from the thalamus to the cortex for conscious awareness (Stream of thinking) and to the hypothalamus for stream of feeling.
Output from the cingulate cortex allows for top-down control of emotional responses
Thinking controls and guides our emotional responses, can increase or dampen them
What are the risk factors for a specific phobia?
Heritable (43%) and environmental (like a traumatic experience with the stimulus)
What brain region is activated with specific phobias?
Amygdala
How do you treat a specific phobia
One-session treatment involving exposure and modeling (decreases L insula and ACC levels)
What brain regions are associated with social phobia
Robust amygdala activation and some insula activation.
How do we treat social phobia?
Nefazodone:
Increases in the middle frontal gyrus, ACC, hippocampus.
Decreases in the DL and MPFC and dorsal ACC (cog control and self-reference)
Agoraphobia
Fear of having a panic attack in a place where you cannot escape ( very heritable). Interoceptive fears (fear of fear)
What brain areas are implicated in panic disorder?
Insula, anterior cingulate, periaqueductal gray matter
How do we treat panic disorder?
SSRIs, Benzos, SNRIs, TCAs, CBT
What is GAD?
Excessive and uncontrollable worry for >6 mo with additional symptoms like sleep problems, muscle tension etc
What are the common areas that reflect common denominator of fear network
Amydala, insula, ACC
PTSD DSM-5 Criteria
A. Exposure to actual or threatened death, serious injury or sexual violence
-directly, witness in person, hearing about it happen to someone close to you, experiencing repeated exposure to details of a traumatic event
- Need to re-experience and avoid
- Have negative alterations in cognition and mood
- Arousal
Duration: >1mo with distress and impariment
What brain areas are involved in PTSD
Amygdala, hippocampus, vmPFC
What brain region is required to extinguish fear response?
vmPFC
