Background: Anthony David McPartlin  (born 18 November 1975) is an English television presenter, producer and actor. He is best known for working alongside Declan Donnelly as part of the presenting duo Ant & Dec. McPartlin came to prominence, alongside Donnelly, in the children's drama series Byker Grove, with both men establishing successful careers as television presenters, in which they are most known for presenting SMTV Live (between 1998-2001), I'm a Celebrity...Get Me Out of Here!
Context: On 22 July 2006, McPartlin married his longtime girlfriend and make-up artist Lisa Armstrong at Cliveden, a country house hotel in Buckinghamshire. The pair remained married for 11 years, before eventually announcing their divorce on 15 January 2018.  McPartlin was mainly a Labour Party supporter until the 2010 election, when he voted for the Conservatives. In February 2013, he told The Guardian newspaper that he would struggle to justify voting for either political party in the future "at the moment".  In 2015, McPartlin went into hospital for an operation to treat his knee, but was forced to take prescription drugs to combat pain after the surgery was botched. Over the course of the following two years, he slowly became addicted to taking the drugs along with alcohol, including prior to any television appearances he made, and struggled to combat against this. In June 2017, McPartlin eventually sought treatment for his addiction and checked himself in for rehabilitation, and was released two months later. On 18 March 2018, McPartlin was involved in a road traffic accident in London which led to him being arrested on suspicion of drink-driving. The following day, on 19 March, he met with his colleague Donnelly and ITV, whereupon he suspended further presenting duties in order to return to rehab for further treatment. Two days later, on 21 March, McPartlin was interviewed under caution and subsequently charged with drink-driving, whereupon he plead guilty to the offence at Wimbledon Magistrates' Court the following month on 16 April, and was fined PS86,000 and banned from driving for 20 months.
Question: why did they dvorce?. Whats the answer?
he slowly became addicted to taking the drugs along with alcohol,