The former married couple are currently suing each other in Virginia, United States. It was sparked after Johnny Depp sued his ex-wife for defamation for $50m over an opinion piece she published in the Washington Post where she described herself as a survivor of domestic abuse. Ms Heard counter sued and now a trial is taking place. The trial has attracted plenty of attention since it began in April. Gawker reports that the “#justiceforjohnnydepp” hashtag on TikTok has over 1.1bn views. A livestream of the trial continues to attract huge attention, with people commentating on the proceedings. Among the many comments the term ‘gaslighting’ has been heavily used – and if you search ‘gaslighting Johnny Depp’ on YouTube it brings up a number of videos. SEE ALSO: 9 things it is now illegal for your partner to do to you in a relationship But what exactly is gaslighting and is it illegal in the UK? What is gaslighting? Gaslighting is a form of psychological manipulation, where someone manipulates another person into doubting their own sanity. Where does the name come from? The name comes from the 1944 film Gaslight in which a young woman whose husband slowly manipulates her into believing that she is descending into insanity. Is it illegal in the UK? It is recognised as a criminal offence in the UK.