Compared to other major psychiatric disorders like depression, schizophrenia, or bipolar disorder, generalized anxiety disorder — a category under which many anxiety-related disorders fall — is relatively understudied from a genomic standpoint.

The prevalence of these disorders, combined with the dearth of genomic data for them, led Indiana University School of Medicine's Alexander Niculescu to use an integrative, translational research approach to study anxiety disorders, with an eye toward developing personalized treatments.

In an April 2011 Translational Psychiatry paper, Niculescu and his colleagues describe how they identified several candidate genes, blood-brain biomarkers, and possible mechanisms for anxiety disorder. Niculescu and his team found notable genetic overlap between anxiety and schizophrenia. That the two appear to be somewhat genetically interdependent led Niculescu's team to propose "schizo-anxiety" as a new diagnostic domain. Genome Technology's Matthew Dublin spoke with Niculescu about the study. What follows is an excerpt of their conversation, edited for space.

Genome Technology: What was your strategy for mapping the -genomic landscape of anxiety disorders?

Alexander Niculescu: We used an approach that we developed over the last decade called "convergent functional genomics." This is essentially like a Google page-rank algorithm wherein the more lines of evidence converge on a gene or biomarker, the higher it comes up on your prioritization list. The lines of evidence that we're using are in our own experimental data — primarily gene expression and animal models — but also integrated with our own gene expression and genetic data from human studies and the existing literature. In a nutshell, we did some animal model experiments with gene expression studies in the brain and blood of those mice, we prioritized those genes using the convergent functional genomics approach, and we did higher-order analysis looking at biological mechanisms and pathways involved.

GT: How is your research geared -toward the treatment of anxiety-related disorders?

AN: Our work has always been about taking things to the clinic. We have a lot of work in the lab where we look at human blood gene expression studies as a way of finding blood biomarkers and developing blood tests for psychiatric disorders, so we have an active research line in mood disorders and psychotic disorders and so on. This foray into anxiety ... we're trying to do what we did for bipolar disorder and schizophrenia, where we developed prototype blood biomarker tests that could have clinical applications. We identified some very interesting candidate biomarkers that are co-directionally changed in blood and in the brain. … The next step is to validate these biomarkers in human studies, and that's what we're doing now.