One in a hundred people suffers from schizophrenia. Characterized by hallucinations, delusions and gross disorganization of thought and speech, schizophrenia is a chronic, severe and disabling brain disorder.
During a psychotic episode, schizophrenics may hear voices no one else can hear. They may suffer from paranoia, believing people are reading their minds, controlling their thoughts or plotting to harm them. This can terrify people with the illness, causing them to become withdrawn or extremely agitated. In worst case scenarios, schizophrenics may harm themselves or others.
Treatment can be highly effective, allowing those with schizophrenia to live rewarding and meaningful lives in which they can hold down jobs and maintain relationships. The danger of relapse, however, is ever-present.
Michael Dawson, professor of psychology at USC Dornsife, is researching physiological indicators that could serve as a valuable tool to help predict — and ultimately prevent — those relapses.
“Schizophrenics are vulnerable to relapse but they don’t know when and their doctors don’t know when, so developing a method that would enable us to predict relapse is very important,” Dawson said. “It would enable the treating psychiatrist and psychologist to intervene immediately to increase medication and psychotherapy. Signs that a relapse is about to occur may signal a crisis in the patient’s life that we are not aware of and which needs to be urgently addressed.”
In September 2012, Dawson shared his research at the international Society for Psychophysiological Research’s annual symposium, held last year in New Orleans.
A past president of the society, Dawson placed his research on schizophrenia in a theoretical framework of vulnerability and stress. “Our physiological measures can be used to indicate a person’s vulnerability to schizophrenia and can be used to detect when those afflicted are under stress that might trigger a psychotic episode,” he told delegates.
Dawson’s research measures skin conductance related to sweat gland activity. To do this, a small electric current is passed through electrodes attached to the fingertips.
“Sweat glands secrete sweat which is a good conductor, so conductance goes up when people become anxious and their sweat glands become more active,” Dawson said.
“What we have found is that conductance increases not only when schizophrenic patients are having a psychotic episode, but also a week or two before they have one,” he said. “There is more activity and higher arousal as the autonomic nervous system — which controls breathing, heart rate and sweat glands — is activated. There are no behavioral signs of this and it’s not otherwise noticeable, either to the clinicians or the patients.”
While Dawson’s research shows that before a relapse there is always an increase in skin conductance, it also presents false positives: patients showing increases with no subsequent relapse.
“It’s as if the patients are approaching a metaphorical cliff. Whether or not they will fall off that cliff, we don’t know. Sometimes they may veer away from the edge. What is interesting is that the patients themselves are not aware of any approaching danger of relapse.”
Dawson hopes that his research can eventually lead to an early warning system that will alert schizophrenics and their doctors to an impending psychotic episode, thus enabling them to take the necessary action to prevent the episode from occurring.
Joining USC Dornsife in 1984, Dawson is well known for his application of psychophysiology to schizophrenia. His areas of interest include cognitive neuroscience, affective neuroscience, and affective conditioning.
He has received 25 years of continuous grant support from the NIMH and is the recipient of two prestigious awards, the Method To Extend Research in Time (MERIT) Award (1998-2005) and the Research Scientist Development Award (1993-98 and 1998-2005).
Dawson is also a USC Dornsife alumnus, earning his Ph.D. in psychology in 1967.
“As a graduate student, I was drawn to USC by the fact that it had some of the top professors in psychology,” he said. “It was already a great place to study the subject then, and the faculty and students have got even better every year since.”
His mentor during this time was William Grings, then chair of the psychology department, with whom he later co-authored the book Emotions and Bodily Responses (Academic Press, 1978).
“I don’t think I could have received the kind of personal attention I received here as a graduate student anywhere else,” Dawson said. “It’s so important.”
He strives to transmit that same close personal attention to his own students. Many are involved in his pioneering research showing that healthy human subjects must be cognitively aware for conditioning — the process of behavior modification in which a subject is encouraged to behave in a desired manner through positive or negative reinforcement — to be successful.
His research bucks the traditional belief that conditioning can occur unconsciously.
“Most people think that conditioning is an automatic, unconscious process,” Dawson said. “But we’ve done a number of studies over the years using healthy college students and we’ve found that in the case of physiological responses, people must be aware of the relationship between stimuli and the desired behavior for conditioning to be successful.”
Dawson’s research has implications for how therapists use conditioning to help patients suffering from phobias. An example of this kind of therapy would be encouraging a patient with a phobia of snakes to relax in the presence of a “safe” caged snake in order to help overcome fear.
“In order for any kind of therapy involving new conditioning to work it must emphasize cognitive awareness. We must not assume it is an automatic process that can take place without explicit information.”
“Our research has changed people’s perception of conditioning but there are still a number of people who hold to the traditional theory. The debate continues.”
Dawson is currently organizing funding for a research study that will advance his goal of developing an early warning system for relapses in people with schizophrenia.
“Until now we have tested patients weekly in the laboratory and that’s how we found out they were going to relapse,” Dawson said. “Now the development of new technology in the form of a device to measure skin conductance, which can be worn like a wrist watch by patients at home, could provide a much more accurate and convenient early warning system.”
The device could provide continuous monitoring of changes in skin conductivity thereby providing Dawson with more precise information. It would also remove the need for patients to come into the laboratory every week.
“We want to test that technology, and if the results are as good we expect, we will share them with clinicians,” Dawson said. “This could be what we are looking for to help prevent patients from having a relapse.”