New research from the University of Maryland School of Dentistry (UMSOD) and the University of Nevada, Reno School of Medicine (UNR Med) finds evidence that points to physical differences among groups of people with schizophrenia.
Schizophrenia is a chronic and severe mental disorder that affects how a person thinks, feels, and behaves. “Although schizophrenia is not as common as some other mental disorders, the symptoms can be very disabling,” said Brian Kirkpatrick, MD, chair of UNR Med’s Department of Psychiatry and Behavioral Sciences. “People with schizophrenia have a wide variety of symptoms, but the most typical symptoms are hallucinations and delusions.”
Gary Hack, DDS
The causes of schizophrenia are not well understood, but new research led by Kirkpatrick and co-authored by Gary Hack, DDS, associate professor in UMSOD’s Department of Advanced Oral Sciences and Therapeutics, is shedding light on the question of causation, with findings that may lead to better understanding of the disorder.
The team’s new research has recently been published in Schizophrenia Bulletin, a peer-reviewed journal of psychosis and related disorders. The recent article, titled “An Early Developmental Marker of Deficit versus Nondeficit Schizophrenia,” provides evidence that patients suffering from a specific form of schizophrenia have a wider oral palate than people with other forms of the disease and people without schizophrenia.
Kirkpatrick and Hack teamed with Dr. Emilio Fernandez-Egea, a psychiatrist at the University of Cambridge in the United Kingdom, as well as two Turkish investigators, Dr. Özlem Gürbüz Oflezer, a dentist from the Department of Prosthetic Dentistry at the Ministry of Health in Istanbul, and Dr. Mehtap Delice Arslan, from the Department of Psychiatry of the Barkirkoy Research and Training Hospital for Psychiatry, Neurology, and Neurosurgery in Istanbul.
The international, interprofessional team collaborated on oral palate studies comparing two groups of people with schizophrenia, those with or without “deficit” features. Deficit schizophrenia is a form of the disease in which patients consistently experience at least two negative symptoms of the disease, such as amotivation or asociality. Deficit schizophrenia is thought to be a separate disease from other, nondeficit forms of schizophrenia.
“Our finding of physical orofacial differences in schizophrenia suggests that the whole-body model of this illness is not only more accurate but is a more appropriate model to present to patients, their family members, and students,” said Hack.
“This palate difference in the deficit patients may reflect abnormal development during the prenatal period,” said Kirkpatrick. “A recognizable palate typically forms between weeks six and 17 during pregnancy, when most neurons travel from their birthplace to their final position in the brain.”
Kirkpatrick plans additional studies of the palate difference and the underlying causes of its development. "If our finding is replicated, the wider palate would be a marker of a different developmental history for deficit compared to nondeficit schizophrenia and would support the concept that deficit schizophrenia is a separate disease within the syndrome of schizophrenia."
The importance of this finding, said Kirkpatrick, “is that it suggests that the development of this group of patients begins to differ from that of other people with schizophrenia as early as the end of the first trimester or the beginning of the second trimester of pregnancy.”
Hack added that the new findings “may point to one pathway to the development of schizophrenia with these negative symptoms that involves specific genes and exposure to a virus.” In the paper, the authors speculate that several factors could account for the development differences and note the greater prevalence of certain antibodies in deficit than in nondeficit patients. This hypothesis would need to be examined in future studies.
“The success of this research advance has depended on very different disciplines coming together to make it happen,” said Kirkpatrick. Hack added that “it’s been rewarding to collaborate with researchers from around the world, and exciting to find a difference in events from the earliest stage of patients’ lives, which may lead to an understanding of one cause of schizophrenia in this group of patients. International research collaborations make positive impacts on global health possible.”