30 years of solitary confinement: What has changed, and what still needs to happen.

Solitary confinement cells are where those considered to be too dangerous to themselves or to others, too troublesome, too mentally unwell, or simply different, will be locked away, spending 22-24 hours a day alone, out of sight and out of mind.Solitary confinement is an extreme and harmful practice on the cusp of prohibited treatment of people deprived of their liberty, with potentially grave consequences for the in-dividuals concerned and the societies to which they eventually return. This article reflects on some of the achieve-ments, and remaining challenges, around the use and regulation of solitary confinement practices internationally in the last 30 years, drawing on recent developments and the au-thor's work in the area.