Final answer:
Illicit drug use generally peaks during late teens to early 20s, aligning with early adulthood, a phase marked by significant life transitions and higher physical capabilities, as well as historical increases in substance misuse due to social factors.
Step-by-step explanation:
The peak of illicit drug use typically occurs during the late teens to early 20s. This age range corresponds to early adulthood, a period when many individuals are completing their education, starting careers, and forming intimate relationships. Additionally, this is when physical strength and performance often reach their highest levels, which may coincide with an increased risk of substance misuse including anabolic steroids, especially among male weightlifters. Societal pressures, enhanced access, and experimentation during this phase of life contribute to this peak in drug use. Moreover, the historical context shows an intensification of drug-related issues during this period, as exemplified by the war on drugs in the 1980s that focused on the misuse of substances like crack cocaine predominantly among young adults.