Anxiety is a universal, adaptive human experience keeping us alert and safe from danger. It produces our “fight or flight” responses to perceived threats. Anxiety is also a motivating emotion under normal circumstances, driving us to action to achieve goals. When anxiety reaches significant heights, however, it becomes problematic and creates multiple physical symptoms, maladaptive behaviors, and extraordinary human misery—in addition to psychological symptoms of worry or fear.
Anxiety problems may range from mild and annoying physical symptoms that cause little worry to disorders where patients’ lives are filled with dread, incapacitating physical symptoms, and avoidant behavior(s) that can reach paralyzing proportions. Anyone who has been acutely frightened or placed in unexpected stressful situations can easily identify the emotional and physical symptoms that accompany the experience of anxiety.
Anxiety disorders are the most common psychiatric illnesses overall.1 Although they may occur at any time in the life cycle, they usually have their onset during adolescence and young adulthood and can become a life-long burden.2 A recent comprehensive “review of the reviews” of the prevalence of anxiety disorders reveals wide ranges of prevalence, upwards of 25% for “any disorder.”3 The prevalence was particularly high in women, young adults, persons with chronic illnesses, and individuals from Anglo-European cultures.
The neurobiological basis of the anxiety disorders involves “loop networks” within the brain. The fundamental structures recognizing and responding to threat in the environment include the thalamus, amygdala, dorsal anterior cingulate cortex (dACC), hypothalamus, hippocampus, and medial prefrontal cortex (mPFC).4 The thalamus is the structure that integrates all sensory input, then sending it to the hypothalamus. The amygdala and dACC process threatening stimuli and send it to the hypothalamus which relays it to the basal ganglia and brainstem resulting in rapid, unconscious, and reflexively defensive behaviors such as startle responses and sudden muscular withdrawal. The contextual features of threat are encoded in memory by the hippocampus. The mPFC is then involved in the “top down” regulation of the threat information resulting in an adaptive, conscious response. Several investigative methods have identified specific neural loops producing nuanced differences that correlate with specific anxiety disorders.4 The major neurotransmitter pathways involved in anxiety are the GABA, noradrenergic, and serotonergic systems that provide the basis for pharmacologic treatment strategies.5
DIAGNOSTIC AND TREATMENT ISSUES COMMON TO ALL ANXIETY DISORDERS
The anxiety disorders in DSM-5 have many overlapping symptoms and features in common.6 They have, however, important distinguishing features critical to effective differential diagnosis. Likewise, anxiety treatments overlap with depression and among the various anxiety disorders themselves. This makes treatment easier because the doses and regimens are similar in the various disorders, although often starting lower and increasing more slowly with the anxiety disorders.
Primary care providers must also consider all the patients who struggle with symptoms of ...