More than 250 people were subjected to painful electric shocks, designed to change their sexual preferences and gender identity, in NHS hospitals between 1965 and 1973, the BBC has discovered. Three Electric Shock Aversion Therapy (ESAT) survivors have told of physical and lasting psychological pain they experienced as teens at the time. One, Jeremy Gavins, 72, said shocks were so severe he lost consciousness and woke up in hospital three days later.