I suggest you start by researching these drugs. Make a list of the characteristics, including negatives and positives of each drug. Take notes.
These sites will help you.
https://www.google.com/search?source=hp&ei=7ogpW8OYMOeMtgX7g6D4DQ&q=compare+and+contrast+essay&oq=compare+a&gs_l=psy-ab.1.1.0j0i20i264k1l2j0l7.1826.4195.0.10041.10.9.0.0.0.0.134.1034.0j9.9.0....0...1c.1.64.psy-ab..1.9.1033.0..35i39k1j0i131k1.0.8JfPiHyd9FM
Compare and contrast the similarities and differences of legal drugs, particularly caffeine, alcohol, and nicotine to illegal/prescription drugs such as amphetamines, narcotic pain killers, marijuana, and Xanax
2 answers
I find it odd that illegal and prescription drugs are combined in the same group. Prescriptions are legal drugs also...abused yes...but legal.