Dr. Petrie is an Associate Professor with the University of Washington Department of Psychiatry and Behavioral Sciences and a staff psychiatrist at the Veterans Affairs Medical Center in Seattle. Many Alzheimer’s Disease Research Center participants meet Dr. Petrie during their research appointments.
What is your role with the ADRC?
I see participants for clinical trials of new investigational treatments, for the biomarker study (see article, page 1, in this issue), and for their yearly ADRC registry evaluations.
During the yearly assessments, I perform the neurological examination, examine the results of the cognitive (memory and thinking) assessment, and spend time with participants and their study companions. A study companion is someone who knows the participant well and through an interview with a member of our staff describes the participant’s abilities in daily life such as being able to perform self-care, household work, and leisure activities. Later, I meet with the ADRC staff to discuss all of this information and come to a consensus regarding participant diagnoses. We categorize participants as cognitively healthy or as having mild cognitive impairment, Alzheimer’s disease, or another neurological disorder. For example, participants who experience difficulties in one or more cognitive functions, such as memory or language, but are able to function normally are diagnosed with mild cognitive impairment, whereas participants whose memory or cognitive difficulties impact their functioning are diagnosed with Alzheimer’s disease or another dementia. Also, when people volunteer to donate spinal fluid for our research, I perform some of the lumbar punctures.
How did you become involved with research in the ADRC?
I attended medical school and completed my internship at the UW and then did my psychiatry residency training at Stanford University. After my residency, I spent a year in a fellowship program at the Palo Alto VA studying biological factors involved in a mental illness called schizophrenia. When I was in medical school, I spent a summer doing research with William Bremner, an endocrinologist at the Seattle VA, which influenced me to return here in 1990 after completing my residency training. Later, I met Drs. Murray Raskind and Elaine Peskind and joined their research group studying aging and memory disorders.
Tell us about your own research.
My major research interest is connected to a Career Development Award I received from the National Institute on Aging. This project uses innovative neuroimaging methods to measure different types of brain activity. We are focusing on a receptor in the brain for norepinephrine, a stress hormone that is involved in producing a “fight or flight” response. We are interested in studying norepinephrine because autopsy studies have shown increased levels of norepinephrine-producing enzymes and norepinephrine receptors in some of the brains donated by patients who had died with Alzheimer’s disease. These same individuals had suffered from difficult behaviors such as irritability, pacing, wandering, yelling, resisting help with bathing and dressing, and striking out at others.
This research dovetails with the research by Drs. Raskind, Peskind, and Wang which suggests that prazosin, a medicine that blocks one type of norepinephrine receptor in the brain, may be helpful in decreasing difficult behaviors in patients with Alzheimer’s disease. The beneficial effects of prazosin suggest that seeing images of norepinephrine receptor activity in living patients with Alzheimer’s might be useful in determining the cause of difficult behaviors and developing additional treatments for those behaviors. We are collaborating with Satoshi Minoshima, MD, PhD, a UW nuclear medicine physician who has contributed to PET imaging techniques for diagnosing Alzheimer’s, and John Grierson, PhD, a UW radiochemist, to develop a radioactive compound that could be used to help us see norepinephrine receptors and measure norepinephrine nerve activity in the brain.
I am also working with Dr. Peskind in her research on spinal fluid biomarkers for Alzheimer’s disease. Patients with Alzheimer’s disease tend to have some less active brain regions, and hints of this decreased activity can be seen in PET images of the brains of some cognitively normal persons with genetic risk factors for developing Alzheimer’s. We are using a radioactive sugar molecule that accumulates in particularly active brain neurons to help us spot these abnormalities in PET scans. Using this method, we recently found associations between these abnormalities and the levels of specific Alzheimer’s disease biomarkers in the spinal fluid of cognitively healthy participants. With continuing research, this could become a way to predict the development of AD or begin treatment of the disease before symptoms ever develop.
Then do you follow those people to see if they develop AD?
That’s what we’d like to do. Because the ADRC research volunteers are followed every year, it’s possible that we could perform that type of follow-up study. That’s why it’s so valuable that our ADRC volunteers are willing to come back year after year to go through the neurological exams and the paper-and-pencil tests and to have their study companions interviewed. If we are successful in obtaining funding for a follow-up study, we could do additional PET scans over time to see if the people who have the strongest relationship between abnormal levels of biomarkers and PET scan findings develop memory problems later in life. This is an example of one of those tantalizing early findings where only time will tell if it turns out to be really important or not.
What do you like to do in your free time?
Well, I go to the gym. I pay this trainer money to make me feel miserable (in the short-run) by making me do squat thrusts and other aerobic and weight training exercises—although I feel great later, and of course, research tells us that physical exercise reduces one’s risk of developing dementia later in life! I also enjoy going to the symphony and reading. Recently, while on jury duty, I read The Last Lecture. The co-author, Randy Pausch, was a computer science professor who was diagnosed with pancreatic cancer. With six months to live, he gave a lecture at Carnegie Mellon speaking to the question, “What would you say if you knew you were going to die and had one chance to sum it all up?” In this case Pausch really was going to die and his lecture created quite a sensation. This was then written as a book for his three young children for whom Pausch is recording all of the fatherly advice he won't be around to give later on.
I enjoy living by the Woodland Park Zoo. I like talking to my daughter who is in her last year of college in New York City. She is majoring in Latin American studies and maybe global health. She plans to travel in South America next year and to do an internship with the Pan American Health Organization.
Did you always want to be a doctor?
No, I was in my second year of community college, and somebody said to me “you should be a doctor.” As for being a psychiatrist, it was partly an outgrowth of my interest in biology, psychology, and anthropology courses, but my interest in psychiatry crystallized during a visit to the United Nations. I saw a book about neurochemistry and psychiatry in the United Nations bookstore, and I thought, “This is exactly what I want to do!” I knew I wanted to study psychiatry and how the brain influences behavior, so that set me on my path
What do you like most about the ADRC?
One of the things I enjoy in the clinic is having the time to answer research volunteers’ questions about Alzheimer’s disease and other dementias. People often say things like, “I read this on the Internet or in a news article—can you tell me more about it?” This is a benefit of participating in our research program—participants can ask questions of medical professionals who are actively involved in both patient care and clinical research. It also keeps me on my toes; there’s nothing like being asked questions to make you really know your stuff.
I also like the people: all the members of the staff are great to work with and the research participants are wonderful. I like meeting people who are older and their families. I appreciate that we have some time to sit and talk; I can think of so many great life stories that I have been able to hear.