Panel: Encountering Daily Life:
Susan Mineka, Ph.D., Professor of Psychology at Northwestern University, is also Co-director of the Panic Treatment Clinic at Evanston Hospital.
The principal and most obvious symptom of an anxiety disorder is an unrealistic, irrational, disabling fear. There are six primary types of anxiety disorders: specific phobias, social phobia, panic disorder, generalized anxiety disorder, obsessive compulsive disorder, and post-traumatic stress disorder. An estimated 23 million Americans suffer from one or more anxiety disorders at any moment.
Historically, these disorders have been attributed to traumatic conditioning experiences, which do underlie many phobias and anxiety states but not all. My research on primates illustrates the complexity of the origins of these disorders. How do we account, for example, for phobias in people who have no known traumatic conditioning history?
Anecdotal evidence long suggested that people probably can acquire phobias through observing another behaving fearfully in the presence of some object or situation, a process known as observational or vicarious conditioning of fear. Studies of rhesus monkeys provided empirical evidence. Laboratory-reared rhesus monkeys do not show a fear of snakes, so this fear is not innate. After lab-reared monkeys observed for only a few minutes a wild-reared monkey reacting with intense fear to a live boa constrictor, they exhibited a similarly intense fear of snakes when tested alone. Like human phobias, these fears were persistent and enduring. The monkeys acquired the fear even when they only watched the models on videotapes, suggesting how potent the media can be for humans.
Yet not everyone who undergoes traumatic observational experiences acquires fears or phobias. Part of the explanation lies in genetic and temperamental variables. We also discovered, however, that experience before or after a traumatic or vicarious conditioning experience can exert a powerful effect. One can protect an animal against acquiring a fear of snakes by first exposing it to a model that is not afraid of snakes and reacts to them without fear. Monkeys first exposed to such a model monkey remained unaffected by later exposure to fearful models. The human child of a phobic parent similarly might be immunized against developing a phobia by first being exposed to non-fearful models.
Another kind of immunization occurs if an infant has early experience with controlling important aspects of its environment. Developmental psychologists long have argued that such experience promotes secure attachment relationships, exploration of novel events, and less fearful reactions to strange or arousing stimuli. Studies with infant monkeys reared in controllable and noncontrollable environments corroborated this. Monkeys who were "masters" of their world could pull levers to deliver to themselves food, water, and treats. Another group received the same food, water, and treats but only when a "master" monkey earned them. Tested in several frightening and novel situations between seven and eleven months of age, the "masters" adapted more quickly and showed more curiosity than those who had not been able to control their environment.
Much of my current research attempts to understand how emotional disorders such as phobias, anxiety, and depression distort human cognitive processing. Emotional states, particularly negative ones, have powerful--often reciprocal--effects on our cognitive processing as well as on our social relationships. Not only do our emotions affect our thoughts and relationships, but these effects, in turn, can influence our emotional state.
Investigators have identified distortions in the cognitive processes of people with these emotional disorders--the ways in which they process emotional information--that seem significant in making these disorders so persistent. Depressed people, for example, appear biased to remember negative experiences and forget positive ones; nondepressed people tend to do the opposite. If depression causes you to remember bad events, your bad memories are likely to exacerbate your depression. People who are clinically anxious show a different bias: their attention is drawn toward threatening stimuli in their environment. If you are anxious and your attention is preconsciously drawn to threatening stimuli, your anxiety may be exacerbated.
People who are anxious and depressed also manifest judgmental or interpretive biases. For example, they tend to overestimate the likelihood of bad things happening to them and also tend to interpret ambiguous information in a negative manner. People who are phobic are prone to overestimate how often bad things actually have happened to them specifically in the presence of stimuli they fear. This tendency to overestimate the relationship between feared stimuli and bad outcomes suggests that phobics seem to process information in a manner that may perpetuate or enhance their fear.
We are trying to maximize the effectiveness of cognitive behavioral treatments for anxiety disorders by helping patients understand these distorted cognitions and learn ways to combat them. Panic disorder, for example, can be treated with medications, but cognitive behavioral treatments are at least as effective and have more enduring effects. Someone with panic disorder notices their heart is racing and worries they are dying, a misinterpretation that may escalate mild symptoms of anxiety into full-blown panic. We teach people to interpret more accurately the meaning of their bodily sensations and to relax their breathing, so they can reduce their tendency to panic.
If you have questions or comments on the LC/NIMH Decade of the Brain Project, please contact: [email protected].
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