The research program was started by Dr.
Ann Pulver after completing her training in psychiatric epidemiology and
genetics. The long term goal of the research program has been to contribute to
our understanding of the biological basis of severe psychiatric disorders. By
using both epidemiological and genetic methods, Dr. Pulver hopes to contribute
to the development of a classification of psychiatric disorders which is based
on the biological underpinning of these diseases.
Between 1983 and 1989, the goal of the program was to identify and collect information about a large representative sample of individuals who were hospitalized in the greater Baltimore area. During this six-year period, we screened psychiatric admissions to 15 hospitals in the greater Baltimore area and enrolled 1,670 individuals into our study. Individuals in this group, now referred to as the Maryland Epidemiologic Sample (MES), were interviewed while they were in the hospital. This systematic sampling of admissions to psychiatric hospitals in one geographical area provides advantages to our statistical analyses and the conclusions that can be drawn.
Family members were interviewed to complete a family tree and collect information about the medical and psychiatric histories of the participantsí relatives. We analyzed the clinical and family history information about the individuals in the MES using statistical tests that allowed us to answer questions about the epidemiology of severe psychiatric conditions. Epidemiology is the study of illness from a population perspective. Epidemiologic studies focus on describing risk factors for illness in groups of individuals. The results of our analyses have been published in several scientific journals. Since their initial enrollment in our study, we have re-contacted individuals in the MES over the years. We have re-interviewed many of these participants and have enrolled them in new research efforts such as family studies, neuroimaging (MRI) studies, and follow-up studies.
Because of advances in laboratory methods, in 1989 our focus turned toward identifying and evaluating families for molecular genetic studies. We began by identifying families with more than one individual affected with schizophrenia. All first degree (parents, siblings, and children) and second degree (uncles, aunts, and grandparents) relatives of affected family members were seen for an in-person interview and blood drawing. DNA samples from individuals in these families have been analyzed using molecular genetic techniques to identify regions of the genetic information that may contain genes that put an individual at risk for developing schizophrenia.
In 1996, we made two major changes in our study enrollment criteria: 1) we began to focus on families of Jewish ancestry and 2) we began to include families where only one individual was affected with schizophrenia.
We are not focusing on the Jewish population because we think there is an increased risk for schizophrenia in this community. We are focusing on the Jewish population because the community has evolved from a limited number of ancestors, and because Jewish individuals have historically married individuals of the same ethnic background. This similarity in ethnic background allows researchers to more easily locate disease-causing genes in specific chromosome regions. We have enrolled families with only one individual affected with schizophrenia because of advances in the field of statistics that enable us to use such families in genetic studies.
A potential link between genetic susceptibility to schizophrenia and bipolar disorder led us to begin to study families with bipolar disorder in 1998. Again, we have focused on families of Jewish descent for the same reasons as described above. We do not think there is a higher rate of bipolar disorder among Jewish individuals as compared to the general population. We are focusing on this community because of genetic characteristics that may allow us to more easily locate susceptibility genes.
To date, our research program has enrolled over 7,000 individuals in our studies. Our current studies are enrolling families of Jewish descent that contain at least one living relative diagnosed with schizophrenia, schizoaffective disorder or bipolar I disorder with psychotic features. We ask the family member(s) diagnosed with schizophrenia, schizoaffective disorder or bipolar I disorder (with psychosis) to allow a member of our research group to visit him or her to complete an in-person psychiatric evaluation and blood draw. Other relatives in the family (primarily the parents of the affected individuals, if they are available) are also asked to participate in the study by donating a small blood sample. We may also ask the parents to complete the psychiatric examination as well. Since 1996, we have enrolled individuals representing 3100 Jewish families into these studies.
Beginning in 2004, we recruited individuals of Ashkenazi Jewish descent to volunteer to participate in an anonymous Ashkenazi Jewish DNA Repository. This Repository was established in order to create a resource for anonymous DNAs to serve as a control group or comparison group for our molecular studies. More than 1200 individuals have participated by donating a blood sample and completing a health questionnaire. No names or other identifying information were obtained from these volunteers.