Some medical conditions, like thyroid abnormalities and anemia, as well as certain medications, can produce severe anxiety. Examples of such medications include stimulants like methylphenidate (Ritalin) or amphetamine salts (Adderall), diabetes medications like metformin (Glucophage) and insulin, antimalarial medications like quinine, as well as corticosteroid withdrawal, such as withdrawal from dexamethasone (Decadron). As individuals with panic disorder seem to be at higher risk of having a heart valve abnormality called mitral valve prolapse (MVP), this possibility should be investigated by a doctor since MVP may dictate the need for special precautions when the individual is being treated for any dental problem. While the development of panic attacks has been attributed to the use of food additives like aspartame, alone or in combination with food dyes, more research is needed to better understand the role such substances may have on this disorder.
In a decision context, unpredictability or uncertainty may trigger emotional responses in anxious individuals that systematically alter decision-making. There are primarily two forms of this anxiety type. The first form refers to a choice in which there are multiple potential outcomes with known or calculable probabilities. The second form refers to the uncertainty and ambiguity related to a decision context in which there are multiple possible outcomes with unknown probabilities.
Selective mutism: A somewhat rare disorder associated with anxiety is selective mutism. Selective mutism occurs when people fail to speak in specific social situations despite having normal language skills. Selective mutism usually occurs before the age of 5 and is often associated with extreme shyness, fear of social embarrassment, compulsive traits, withdrawal, clinging behavior, and temper tantrums. People diagnosed with selective mutism are often also diagnosed with other anxiety disorders.
Some research suggests that your body's natural fight-or-flight response to danger is involved in panic attacks. For example, if a grizzly bear came after you, your body would react instinctively. Your heart rate and breathing would speed up as your body prepared for a life-threatening situation. Many of the same reactions occur in a panic attack. But it's unknown why a panic attack occurs when there's no obvious danger present.
When we’re anxious, the body produces a stress response. The stress response is designed to give us an extra ‘boost’ of awareness and energy when we think we could be in danger. The stress response causes a number of physiological, psychological, and emotional changes in the body that enhance the body’s ability to deal with a perceived threat – to either fight or flee, which is the reason the stress response is often referred to as the ‘fight or flight response.’
In the central nervous system (CNS), the major mediators of the symptoms of anxiety disorders appear to be norepinephrine, serotonin, dopamine, and gamma-aminobutyric acid (GABA). Other neurotransmitters and peptides, such as corticotropin-releasing factor, may be involved. Peripherally, the autonomic nervous system, especially the sympathetic nervous system, mediates many of the symptoms. Increased flow in the right parahippocampal region and reduced serotonin type 1A receptor binding in the anterior and posterior cingulate and raphe of patients are the diagnostic factors for prevalence of anxiety disorder.