Chapter 14
Anxiety Disorders and Anxiolytics
- Symptom dimensions in anxiety disorders
- When is anxiety an anxiety disorder?
- Overlapping symptoms of major depression and anxiety disorders
- Overlapping symptoms of anxiety disorder subtypes
- The amygdala and the neurobiology of fear
- GABA, anxiety, and benzodiazepines
- GABA-A receptor subtypes
- Benzodiazepines as positive allosteric modulators (PAMs)
- Novel GABA anxiolytics
- Serotonin, stress, and anxiety
- Stress sensitization
- Alpha 2 delta ligands as anxiolytics
- Noradrenergic hyperactivity in anxiety
- Fear conditioning versus fear extinction
- Fear extinction means learning to forgive but not to forget
- Cortico-striatal-thalamic-cortical (CSTS) loops and the neurobiology of worry
- Treatments for anxiety disorder subtypes
- Summary
Anxiety Disorders and Anxiolytics
This chapter will provide a brief overview of anxiety disorders and their treatments. Included are descriptions of how the anxiety disorder subtypes overlap with each other and with major depressive disorder. Clinical descriptions and formal criteria for how to diagnose anxiety disorder subtypes are mentioned only in passing. The reader should consult standard reference sources for this material. The discussion here will emphasize how discoveries about the functioning of various brain circuits and neurotransmitters – especially those centered on the amygdala – affect our understanding of fear and worry, which cut across the entire spectrum of anxiety disorders.
The goal of this chapter is to acquaint the reader with ideas about the clinical and biological aspects of anxiety disorders in order to clarify the mechanisms of action of the various treatments for these disorders as they are discussed along the way. Many of these treatments are extensively discussed in previous chapters. For details of mechanisms of anxiolytic agents used also for the treatment of depression (i.e., certain antidepressants),
Save image
FIGURE 14-1 Overlap of MDD and anxiety disorders. Although the core symptoms of anxiety disorders (anxiety and worry) differ from the core symptoms of major depression (loss of interest and depressed mood), there is considerable overlap among the rest of the symptoms associated with these disorders (compare the “anxiety disorders” puzzle on the right to the “MDD” puzzle on the left). For example, fatigue, sleep difficulties, and problems concentrating are common to both types of disorders.