Early Career Award Elevator Pitch
Joseph Ghanem
Intro: Hi everyone, my name is Joseph, and my research looks at the way the brains of individuals with a first episode of psychosis change over time and how these changes relate to domains of cognition such as memory.
Background: There are different ways to look at brain changes, but in my research we do so through a measure called Fractional Anisotropy (FA) which looks at how water is moving through the brain’s white matter. White matter being a network of nerve fibers that sends information between different brain regions. High FA indicates healthy, well-organized white matter pathways, Low FA is indicative of a potential problem, such as damage to white matter.
People with a longstanding psychotic disorder do have lower FA relative to healthy populations but there has been debate about how FA changes over time early, right after a first episode of psychosis, with some studies finding changes and others showing that it remains unchanged. The link between FA and verbal memory--the ability to remember words or sentences and recall them--is also unclear. Previous studies are also confounded by small sample sizes and short-term follow-up periods, antipsychotic medication use, and chronicity.
Studying the early stages, over a longer period and with a larger sample, is a promising avenue of better understanding changes in white matter in this population.
Methods: What is unique and exciting about my work is that we are looking at these changes over 18 months at different points in time, which is something that has not been done before using this measure in this population. We are doing so in a sample of 80 people with a first episode of psychosis, which is also larger than most previous studies. As these are individuals recently diagnosed with a first episode of psychosis, it allows us to initially scan their brains before their brains change due to medication.
The way to measure FA is to first scan the brains of participants using Diffusion Magnetic Resonance Imaging, a technique that allows researchers to look directly at white matter. We then preprocess the scans, which is an essential step that removes small errors in the images and improves their quality—think of it as polishing an image.
We then conduct statistical models that compare FA in different regions of the brain between patients and controls
Results: what we found was that FA did not differ between those with a first episode of psychosis and healthy controls, there was also no meaningful association between FA and verbal memory.
Meaning: Our findings suggest that differences in FA are small early on after a first episode of psychosis, which can be taken as an indication that this period is critical for intervening before changes start to occur. It is also possible that longer time periods are needed to begin seeing changes in FA.
