Biological Factors- Anxiety disorders

Overactive limbic system

The limbic system is overly reactive to threats; leading to greater fear and anxiety responses.

Amygdala

Receives info from senses; tells the hypothalamus to respond; leads to activation of the sympathetic nervous system and fight-flight-freeze.

Prefrontal cortex

Thinking/planning; evaluates the situation and acts on the amygdala; which stops sending the alarm so we can calm down.

Anxious people and the PFC

There may be poorer connections between the PFC and amygdala.

HPA axis

Hypothalamus → pituitary → adrenal; leads to release of cortisol; a stress hormone.

Cortisol

Helps the body manage stress; but can cause greater fear or anxiety symptoms if imbalanced; too much or too little cortisol.

Biological theories of specific phobias

Genetics and twin studies suggest a genetic component; possibly different genes for different phobias.

Genetics and anxiety disorders

Twin studies suggest a genetic effect and a general tendency toward anxiety.