Prisoners who are isolated for prolonged periods of time have been known to experience "depression, despair, anxiety, rage, claustrophobia, hallucinations, problems with impulse control, and/or an impaired ability to think, concentrate, or remember."
(2) Studies have also shown that isolation can cause "impaired vision and hearing... tinnitus [(ringing in the ears)], weakening of the immune system, amenorrhea [(absence of menstrual periods in women)], premature menopause... and aggressive behavior in prisoners, volunteers and animals."
(1)