Is it possible to predict the risk of developing a major mental illness? Elaine Walker, Samuel Candler Dobbs Professor of Psychology and Neuroscience, answers this question by investigating early signs of schizophrenia and major depressive disorders from childhood to young adulthood. Currently, Walker's research focuses on adolescence because this is a critical developmental period for the emergence of behavioral signs of risk for schizophrenia.

Over the past ten years, Walker has studied adolescents manifesting a syndrome called schizotypal personality disorder (SPD). This syndrome entails subthreshold psychotic symptoms, and 25 to 40 percent of youth who manifest SPD develop a psychotic disorder by early adulthood. She seeks to understand why some teenagers who manifest SPD go on to develop schizophrenia, while others show a stable course of symptom severity - and still others grow up to lead healthy adult lives.

As adolescence progresses, the signs that something is wrong grow more obvious than they did in early childhood. Walker's study of SPD has demonstrated that the symptoms of this illness have both maturational and environmental precipitates - natural changes in the adolescent brain as well as situational stresses. Her research has demonstrated an association between hormonal changes during adolescence and the emergence of psychiatric disorders. Walker and other researchers have shown that the neural system governing the stress response in these adolescents is shaped both by the environment and by maturational processes.

In the same project, Walker is studying the connections between changes in adrenal hormones and the progression of SPD. The etiologic model on which she bases her work assumes that hormonal changes during adolescence can trigger the expression of genes linked with risk. These same changes might also trigger modifications in the neural circuitry that underlies psychiatric symptoms. Hypothetically, if changes in biological sensitivity to stress are associated with the emergence of psychopathology in adolescents, in the future, preventive intervention might entail modulating those adrenal hormones. Research has shown that both psychosocial and pharmacological interventions can affect the release of hormones, particularly stress hormones. Therefore, future clinical research aimed at preventive intervention may involve attempts to dampen stress hormone secretion in adolescents at risk, thus preventing the onset of more serious mental disorder in early adulthood.

Walker's research at Emory is inherently interdisciplinary. She collaborates with faculty across departments, including Michael Compton in Psychiatry and Joseph Cubells in the Department of Human Genetics, who is interested in the genetic factors associated with the risk for psychotic disorders. In their search for genes associated with the risk for psychiatric disorders, Walker and Cubells collect DNA samples from adolescents. Walker hopes to further the interdisciplinary study of neuroscience through Emory's strategic plan.

Walker acknowledges the importance of preparing the next generation of scholars. Students play "a pivotal role" in all dimensions of her research and teaching. The postdoctoral and graduate students in her research lab implement research and collect and analyze data. Walker's undergraduates work with their senior peers, providing the graduate students with important teaching experience outside the classroom. And when Walker teaches, she engages students with the latest findings from her own scholarship.

Because the National Institute of Mental Health was encouraged by initial findings on adolescents and young adults at risk for psychotic disorders, the agency awarded unsolicited supplemental grants to Walker and seven other research groups in North America who are conducting similar work. As this national research collaboration proceeds, it is expected to result in a large-scale longitudinal project that will explore the relationship between hormonal changes and alterations in brain structure and function prior to the onset of mood and psychotic disorders. Says Walker, "These may be key factors in identifying who is at greatest risk for converting to a major mental illness and what if anything can be done to prevent that." As Walker's work testifies, interdisciplinary studies will allow us to detect mental illness early and to begin working toward preventive intervention.