Mental health articles

Anxiety is common to all ages and is characterized by fear and worry. Anxiety
is normal. For example, children between 6 and 18 months old experience
separation anxiety, and everyone experiences the fight or flight response to
stressful situations. Anxiety becomes a disorder when a person is unable to cope
with stressors and anxiety interferes with the person’s activities of daily
living.
Central to anxiety disorder is the person’s misinterpretation of stressors and
exaggeration of a response to the stressor. A stressor is a situation that triggers
a stress response.

Neurophysiology of Anxiety
The amygdala, located in the temporal lobe of the brain, is involved in detecting
a threat and how a person responds to a threatening situation. A person
constantly receives stimuli, which are processed by the amygdala. If the amygdala
detects the stimuli as a threat (stressor), it signals the hypothalamus to
initiate the stress response. Worrying involves the basal ganglia, which is located
outside the thalamus. The basal ganglia is also involved in obsessive-compulsive
disorder (OCD).

There are two different stress responses; these are as follows:
Autonomic Nervous System (ANS): The ANS response causes epinephrine
to be released from the adrenal medulla into the bloodstream, causing the
heart rate and blood pressure to increase. This is called the fight or flight
response that is associated with anxiety. The fight or flight response is also
referred to as the alarm reaction stage. According to the general adaptation
syndrome, the body attempts to adapt to the stressor by either confronting
the stressor (fight) or avoiding the stressor (flight). The body enters the resistance
stage when the body’s continued attempt to adapt fails. The body
enters the exhaustion stage when it is unable to adapt to the stressor, leading
to illness.
HPA Axis: The HPA axis involves interaction with the hypothalamus, pituitary
gland, and adrenal gland. When a stimulus is seen as a threat (stressor),
the hypothalamus releases corticotrophin-releasing hormone (CRH) into the
bloodstream. CRH causes the pituitary gland to secrete adrenocorticotropic
hormone (ACTH) into the bloodstream, signaling the adrenal gland to secrete
cortisol into the bloodstream. Cortisol decreases inflammation and increases
the use of glucose, leading to the body adapting to the stressor
(adaptive response). If the stressor is not resolved, cortisol continues to be
secreted, leading to hypertension, hyperglycemia, increased cholesterol, and
arteriosclerosis. The patient may also experience memory problems.
The neurotransmitter GABA is related to anxiety. A decrease in GABA is
related to increased symptoms of anxiety. Alcohol and benzodiazepine modify
GABA, thereby lowering anxiety. Withdrawal from these drugs increases anxiety.
Increased norepinephrine also increases symptoms of anxiety

Tags: anxiety disorders