Lecture 10 Flashcards
Depression and Anxiety
fear
An emotional state aroused by specific external stimuli that gives rise to defensive and escape behaviours
anxiety
A generalized response to an unknown threat or internal conflict. Some argue that anxiety occurs when a person recognizes that they are not in control of the outcome of a threatening situation
anxiety disorders
Psychiatric conditions characterized by overactivity of the autonomic nervous system (fight or flight), expectation of an impending threat, and continuous vigilance for danger. (Not caused by drug intoxication or drug withdrawal)
Panic Disorder
- characterized by episodic periods of intense fear and ANS over activation (fast heartbeat, short breath, patients sincerely believe they are dying).
- Its brief and not continuous
Generalized anxiety disorder
persistent state of excessive worry and anxiety serious enough to cause a disruption in normal activities
anticipatory anxiety
a fear of having a panic attack; may lead to the development of agoraphobia.
agoraphobia
a fear of being away from home or other protected place.
○ Social interactions
Think of the lady from Grey’s who couldn’t get off the plane
social anxiety disorder
excessive fear of being exposed to the scrutiny of other people that leads to avoidance of social situations
PTSD
a reaction to a terrifying event that occurs to or is witnessed by the patient. Characterized by flashbacks, nightmares, anxiety, compulsive thoughts about event
Epidemiology of anxiety disorder
most prevalent psychiatric condition, with a lifetime prevalence of at least 20%.
○ 1/5 people will experience Anxiety Disorder in their lifetime
- Gender norms may also make it less acceptable for men to seek out a diagnosis for anxiety
- women are twice as likely as males to develop an anxiety disorder
role of genetics and gender in anxiety disorders
- Females are twice as likely as males to develop an anxiety disorder. This emphasizes the biological nature of disorder but gender may also play a role.
○ Diagnosed twice as often - Genetics does play a role in these disorders based on family and twin studies, but heritability is low compared to other psychiatric conditions (0.3).
- Few genes have been identified. For example BDNF (brain derived neurotrophic factor) may play a role in PTSD. The common variant Val66Met allele found in some humans impairs the ability to forget a fear memory in humans (and in mice)
Chronic psychological stress persistently increases
cortisol and affects neuron synapse numbers
- chronic stress is highly correlated with increased anxiety and depression
how do fMRIs work
Brain regions that are activated have increased blood flow that can be detected.
Detects changes in blood flow because the blood has iron
patients with anxiety disorders show an
over activation of the amygdala (region for fear / anger / negative emotions)
DTI (diffusion tensor imaging) can
study white matter tracts and connectivity
What do DTIs reveal about anxiety
- DTI shows reduced connectivity between frontal cortex and amygdala.
- Research focuses on the stress response, effect of chronic stress. Chronic stress increases cortisol, decreases synapse number in hippocampus and cortex
first line therapy for anxiety disorders
Selective Serotonin Reuptake inhibitors (SSRIs)