McLean Hospital 115 Mill Street Belmont, MA 02478
Dr. Gruber is director of the CCNC and associate professor of psychiatry at Harvard Medical School. Her clinical and research focus is the application of neurocognitive models and multimodal brain imaging to better characterize neurobiological risk factors for substance abuse and psychopathology. Dr. Gruber’s lab has examined the etiologic bases of neural models of dysfunction in patients with psychiatric disorders as well as marijuana-abusing adults. She has published in numerous journals and been the focus of national and international symposia and press conferences.
Dr. Gruber is involved in the application of behavioral science to help shape policies regarding juvenile advocacy. Her ongoing initiative to educate policymakers, judges, attorneys and the public has had local and national impact. She also directs the MIND program, designed to clarify the effects of recreational and most recently, medical marijuana on brain structure, function, and quality of life.
Dr. Gruber’s Cognitive and Clinical Neuroimaging Core (CCNC), established in 2008, is dedicated to studying the relationship between symptoms of psychiatric disorders and substance use, and the ways in which we think, solve problems, and process information. Through the use of various magnetic resonance imaging (MRI) techniques and neuropsychological, clinical, and diagnostic instruments, Dr. Gruber’s goal is to identify risk factors for mental illness and substance use, particularly the examination of cognitive and affective correlates of neural systems that may mediate symptoms of psychiatric disorders and behaviors related to substance abuse.
Primarily, Dr. Gruber is interested in examining the brain as it relates to marijuana use and bipolar disorder, as well as studying the trajectory of brain development in healthy adolescents and adults. Further, Dr. Gruber’s lab collaborates with several investigators on studies related to a variety of disorders including depression, non-suicidal self-injury, and borderline personality disorder. Currently, the lab is exploring the underlying neurobiology of bipolar disorder, substance abuse, and other conditions using various approaches.
Specifically, the lab’s studies focus on altered executive functioning, differential patterns of brain activation, and changes in the brain’s white matter, which plays a critical role in the communication of information between brain regions.
Techniques used in these investigations include measures of neuropsychological performance, clinical and diagnostic instruments, and magnetic resonance imaging (MRI) methods such as functional MRI (fMRI), structural MRI (sMRI), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS)
Recently, work from Dr. Gruber’s group has highlighted differences between those who start smoking marijuana regularly before age 16 compared to those who start later, reporting that earlier marijuana use is associated with poorer cognitive performance, altered patterns of brain activation, and reduced organization of white matter. Further, in earlier onset smokers, lower white matter organization is associated with higher levels of impulsivity.
The lab also employs a multimodal brain imaging approach, including white matter assessment and functional imaging data, combined with cognitive and behavioral measures, to determine the differences that characterize patients with bipolar disorder. This study also investigates the impact of medication, duration of illness, age of onset, and substance use.
Dr. Gruber is also the director of Marijuana Investigations for Neuroscientific Discovery (MIND), which is assessing the impact of medical marijuana on cognitive function. Phase I of the MIND project consists of an innovative study designed to examine the potential impact of medical marijuana on cognitive performance within various clinical populations. In addition, MIND researchers apply behavioral science to help shape policies that address juvenile advocacy and defense. The ongoing initiative to educate policymakers, judges, attorneys, and the general public regarding differences between adults and adolescents has affected local and national policy.
IDEAA (Imaging Data in Emerging Adults with Addiction) Consortium, a multisite group including Dr. Gruber, Krista M. Lisdahl, PhD, at the University of Wisconsin-Milwaukee, Susan F. Tapert, PhD, at the University of California, San Diego, and Francesca M. Filbey, PhD, at the University of Texas, Dallas, uses common, overlapping neuroimaging and behavioral measures in well-characterized marijuana smokers and healthy controls. Data will be pooled in order to create the largest sample of well-characterized emerging adult marijuana users and matched controls to date.
Gruber SA, Sagar KA, Dahlgren MK, Racine MT, Lukas SE. Age of onset of marijuana use and executive function. Psychology of Addictive Behaviors 2011;26:496-506.
Gruber SA, Dahlgren MK, Sagar KA, Gonenc A, Killgore WDS. Age of onset of marijuana use impacts inhibitory processing. Neuroscience Letters 2012;511:89-94.
Gruber SA, Dahlgren MK, Sagar KA, Gonenc A, Lukas SE. Worth the wait: effects of age of onset of marijuana use on white matter and impulsivity. Psychopharmacology 2013;231:1455-1465.
Belmont campus - McLean Imaging Center, Room 172