I watched the video of Madness in the Fast Lane, scary, cannot believe that they could survive all that....even the jump off the bridge.  My opinion is that both twins are hyperthyroid (over active thyroid).  Some years ago when diagnosed as being hypothyroid, my doctor told me a story, when he was working in Weskoppies ( an institution in Pretoria) there was a 'mad' woman there, totally off her head,(also hyperthyroid) had been there for a few years.  A professor came over here from the UK, saw her, just by looking at her, said that she had a thyroid problem, she was put on medication and left the institution within weeks, as sane as any other soul!  A lot of thyroid cases are never correctly diagnosed.
By the way I am also ex-Rhodie.
SIC
Gil