PROJECT SUMMARY Addictive drug use is highly prevalent among college-aged young adults and is linked to the development of substance use disorders and other negative health outcomes later in life. Thus, understanding factors driving use is a critical public health concern. While prior work has linked use to psycho-social factors, increased reliance on technological devices (e.g., mobile phones, computers, gaming consoles), has introduced new risk-factors that cannot be ignored. As digital media delivers a consistent stream of rewarding stimuli, heavy use has the potential to dysregulate neurobiological, reward processing systems implicated in drug use, and result in withdrawal symptoms when prevented. Digital withdrawal symptoms may intensify digital media craving, and craving for other rewards (e.g., drugs), in turn, leading to an increased risk for addictive digital media and drug use. Identifying symptoms of maladaptive technology use that may predispose young adults to escalating drug use is critical. The main objective of the proposed project is to characterize individual differences in neurocognitive digital withdrawal symptoms and drug craving, following a period of digital media abstinence, and assess associations with digital and drug use behaviors. Brain function, and withdrawal symptomology among drug using young adults will be examined before and after a period of digital media abstinence in which participants will surrender their mobile phone over-night and agree to not engage in any screen-time. Specifically, alterations in reinforcement processing brain function and responsivity to drug and technology cues, following acute digital abstinence, will be characterized (Aim 1). Drug craving and digital withdrawal symptoms (physiological, affective, cognitive) linked to acute digital media abstinence will be examined (Aim2). Finally, relations between individual differences in substance and digital media use history, observed digital withdrawal symptoms, and altered brain function will be examined (Aim3). The proposed aims will expand the PI’s existing experience in addiction neuroscience by allowing her to study comorbid risk for addictive digital and substance use and gain new training in, peripheral physiology measurement, high-resolution neuroimaging, and subcortical segmentation techniques.