As indicated in recent spoilers released by the BBC soap, Ian's behaviour becomes erratic in upcoming episodes as he struggles under the pressure of his financial problems, troubles with fiancée Mandy Salter, and his half-brother Ben Mitchell's killer secret.
The storyline culminates in Ian (Adam Woodyatt) doing a disappearing act from Walford, sparking concern about his whereabouts.
EastEnders' executive producer Lorraine Newman told The Mirror: "Adam puts in a fabulous performance as a man teetering on the edge of a breakdown, who finally spirals when delivered a catastrophic blow by someone close to him."
A Walford insider added: "Viewers have seen Ian become increasingly frantic whilst trying to juggle his desperate financial affairs as well as many problems within his family.
"His state of mind gets progressively worse over the next few weeks, with Ian disappearing from Walford and his family frantically worried."
Show chiefs worked with mental health charities, including the Time to Change partnership between Mind and Rethink Mental Illness, while devising the storyline.
Time to Change spokesperson Jenni Regan commented: "We hope an accurate portrayal of what it's like to have a mental health problem, showing this can happen to anyone such as a businessman or family man - just like Ian - will help eliminate the stigma and taboo around the issue."