Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Prescription and Illicit Drug Abuse ?
    ### Response:
    Medications affect older people differently than younger people because aging changes how the body and brain handle these substances. As we age, our bodies change and cannot break down and get rid of substances as easily as before. This means that even a small amount of a medicine or a drug can have a strong effect.
    