Epidemiology of use of specific substances varies over time and by geographical region Illicit drug adulteration is not uncommon, and thus patients may not be using the substance that they think they are using Given the limitations of history and laboratory testing in this patient population, careful clinical assessment and recognition of toxidromes are crucial in guiding management Current Evidence As a special category of pediatric toxicology, exposures to psychoactive drugs are outlined in this section In addition to the classic substances of abuse, it is important to remember that misused and abused substances also include prescription medications (notably ADHD medicines and opioids), OTC medications, herbal products, supplements, and emerging synthetic agents Three distinct pediatric age groups may be at risk from exposures related to substance use: (i) The adolescent or preadolescent who use drugs for their mind-altering effects; (ii) the neonate who is exposed to substances during gestation and manifests signs of intoxication or abstinence after birth; and (iii) the infant or toddler who becomes exposed to drugs of abuse through either active administration by a caregiver (chemical child abuse), the ingestion of a drug left in an accessible place in their environment, or passive exposure created by being in an environment where drugs of abuse are used (e.g., marijuana, cocaine, phencyclidine [PCP], methamphetamine) or manufactured In any of these circumstances, the exposure can be sufficient to produce severe intoxication Thus, knowledge of the epidemiology and manifestations of substance use becomes important in the management of children of all ages