my initial chronic dp state lasted for about 7 months before it started to ease off. that took, with a few ups and downs but generally going in the right direction, a further few months. after that were a few years when i would be in occasional dp states usually due to using alcohol or substances. when not taking anything i was fine for years. latest episode lasted a few months while building up, a couple of months in a bad state(although not the same as the initial chronic state) and its been a few months now of it lessening, thank God.