Dr. Lisdahl's primary focus is on the neurocognitive consequences of chronic drug use during adolescence and emerging adulthood and predictors of substance use onset in youth. More specifically, using magnetic resonance imaging (structural MRI, fMRI and DTI) and neuropsychological assessment, Dr. Lisdahl’s laboratory examines the effects of chronic marijuana, alcohol, nicotine and ecstasy use on brain structure and function. We also attempt to explain individual differences by examining whether genetics, gender or lifestyle factors such as aerobic exercise, physical activity, or adiposity (body fat distribution) moderate these effects.