PSYC 415 -- Study Points for Anxiety Disorders I. Anxiety Disorders A. panic disorder 1. characterized by panic (anxiety) attacks a. shortness of breath b. clammy sweat c. dizziness, faintness d. feelings of unreality e. sometimes mistaken for a heart attack 2. anticipatory anxiety - the fear of an impending panic attack 3. associated with secondary agoraphobia for fear of having a public attack 4. risk: just under 2% 5. about twice as common in women as in men B. generalized anxiety disorder 1. characterized by excessive (free-floating) anxiety, worry, and dread 2. risk: about 3% 3. about twice as common in women as in men C. phobic anxiety D. social anxiety disorder (social phobia) 1. excessive fear of being exposed to public scrutiny 2. avoidance of social situations 3. intense anxiety and distress during unavoidable social situations 4. risk: about 5% 5. equally common in men and women 6. there is probably a genetic predisposition 7. associated with cold, authoritarian fathers and overprotective mothers E. obsessive-compuslive disorder (OCD) - covered separately below F. post-traumatic stress disorder G. possible causes 1. genetic predisposition - family studies and twin studies a. panic disorder - at one time a single dominant gene was proposed b. inheritance pattern is not so strong in other anxiety disorders c. the serotonin transporter gene has been implicated 2. panic attacks can be induced in people susceptible to them a. by infusion of lactic acid or inhalation of carbon dioxide b. has allowed PET scanning studies to be done i. dramatically incr. blood flow & glucose utilization in temporal poles ii. the amygdala is implicated iii. also the ant. cingulate cx and orbitofrontal cx - decr. activation 3. however, they are difficult to study due to overdiagnosis and contamination of subject pools H. treatment 1. traditional anxiolytic drugs a. barbiturates b. benzodiazepines (Librium, Valium, Xanax, etc.) c. alcohol - often self-prescribed esp. for social anxiety 2. these drugs all activate the GABA-A receptor 3. the role of the amygdala in the GABA-A story a. high concentration of GABA-A receptors in the amygdala b. local infusions of benzodiazepines produce anxiolytic effects c. local infusions of GABA antagonists blocks the anxiolytic effects of systemically administered benzodiazepines 4. the GABA theory of anxiety - due to deficient GABA transmission a. decreased sensitivity of receptors - due to a decr. no. of receptors? b. an experiment with cats i. pregnant cats were given diazepam to expose kittens prenatally ii. produced anxious, fearful kittens with decr. no. of GABA-A receptors 5. evidence suggests the anxiolytic action of these drugs is in the amygdala a. high concentration of GABA-A receptors b. local infusion of benzodiazepines produces anxiolytic effects c. local infusion of GABA antagonists prevents the anxiolytic effects of systemically administered benzodiazepines 6. a spanner in the works of the GABA theory a. buspirone (Buspar) is a serotonin agonist (at the 5-HT-1A receptor) b. anxiolytic but not sedating or ataxigenic 7. drugs of choice lately - SSRIs (e.g., Prozac, Zoloft) 8. cognitive-behavioral therapy (esp. with densitization) is useful I. anxiety disorders are often comorbid with depression II. Obsessive-Compulsive Disorder (OCD) A. definitions 1. obsessions - persistent, irresistible, and disturbing thoughts 2. compulsions - same except with behavior (handwashing, e.g.) 3. risk: 1-2% (slightly more in women) B. some interesting parallels 1. amphetamine-induced stereotypy in rats 2. "punding" and "tweaking" in amphetamine addicts C. OCD is associated with Tourette's syndrome 1. characterized by muscular and vocal tics, facial grimaces, pacing, twirling, barking, sniffing, coughing, grunting, repeating specific words, echolalia 2. a tic disorder that starts in childhood (age 5-7 is typical) 3. thought to be an inherited disorder - exact mode of inheritance unknown, and no gene has been identified (may also be sporatic) 4. environmental factors also play a role - streptococcal infections, autoimmune 5. PFC, basal ganglia, cingulate cx, and thalamic circuits have been implicated D. OCD may be an alternate expression of the Tourette's genotype E. some people now classify OCD as a tic disorder F. scanning studies implicate the orbitofrontal cx, cingulate cx, and caudate nuc. G. direct and indirect output pathways of the neostriatum 1. direct (excitatory) pathway - rapid execution of automatic behaviors 2. indirect (inhibitory) pathway - suppressing automatic behaviors permitting a switch to other adaptive patterns of behavior 3. theory - OCD is due to an imbalance between these two pathways (Saxena) a. orbitofrontal cx - recognizes situations that have personal significance and activates the excitatory lope of neostriatal output H. treatment 1. prefrontal leukotomy - disconnecting PFC and cingulate cx from limbic system a. this can also result in typical symptoms of frontal lobe syndrome, however 2. deep brain stimulation has worked in some patients 3. drugs a. clomipramine - a tricyclic antidepressant that is fairly 5-HT-specific b. fluoxetine (Prozac) - an SSRI c. fluvoxamine (Luvox) - an SSRI 4. so what's serotonin got to do with it? - serotonin is inhibitory in the basal ganglia and may work to keep the direct and indirect pathways in balance (and particularly to keep the excitatory direct pathways from getting out of control)