Final answer:
The teenage boy is likely referring to heroin, as it is known for creating euphoria and relieving anxiety before leading to addiction and a cycle of increasing dosages.
Step-by-step explanation:
The drug that the teenage boy is referring to is likely heroin. Initial use of heroin can create a sense of euphoria and alleviate anxiety, but with constant use, tolerance can develop quickly, necessitating larger doses to achieve the same effects.
This progression can lead to addiction, where obtaining and using the drug becomes the primary focus of the user's life, and normal functioning becomes impaired. When addicted to heroin, users chase the high they once felt, but achieving it becomes increasingly difficult, which can result in taking dangerous amounts of the substance.
The addictive potential and severe withdrawal symptoms associated with discontinuation make heroin abuse and addiction a major health concern that often requires professional rehabilitation and treatment to overcome.