text: Persistent behavioral and neurobiological consequences of social isolation during adolescence Meaningful social interactions are a fundamental human need the lack of which can pose serious risks to an individuals physical and mental health Across species peer oriented social behaviors are dramatically reshaped during adolescence a developmental period characterized by dynamic changes in brain structure and function as individuals transition into adulthood Thus the experience of social isolation during this critical developmental stage may be especially pernicious as it could permanently derail typical neurobiological processes that are necessary for establishing adaptive adult behaviors The purpose of this review is to summarize investigations in which rodents were isolated during adolescence then re housed in typical social groups prior to testing thus allowing the investigators to resolve the long term consequences of social adversity experienced during adolescent sensitive periods despite subsequent normalization of the social environment Here we discuss alterations in social anxiety like cognitive and decision making behaviors in previously isolated adult rodents We then explore corresponding neurobiological findings focusing on the prefrontal cortex including changes in synaptic densities and protein levels white matter and oligodendrocyte function and neuronal physiology Made more urgent by the recent wave of social deprivation resulting from the COVID 19 pandemic especially amongst school aged adolescents understanding the mechanisms by which even transient social adversity can negatively impact brain function across the lifespan is of paramount importance 