Solitary Confinement

The first issue that I will be taking up will be the morality and constitutionality of solitary confinement. For this question, I will be looking to answer five questions. These five questions are:

1. What is solitary confinement and how is it used?
2. What are the long term effects of solitary confinement?
3. What are the regulations on solitary confinement?
4. Are there any Supreme Court cases regarding solitary confinement? If so, what were they?
5. What does international law say regarding solitary confinement?

While I answer these questions, I will also be sure to discuss the use of solitary confinement on underage prisoners (under 18 years old), if it is used on them at all.