Lingard was struggling for form and with his mental health during the past 12-18 months at Manchester United.
But he has been revitalised since his loan move to the Hammers in January, scoring at a rate of nearly a goal a game in the Premier League.
Asked about a shift in his environment, Lingard told the club's website: "I think environment is a big thing, as well, when it comes to your mental health.
"At my house in Manchester, you go down, down into the kitchen and it's very dark as it's a bunkery type.
"I used to lie on the couch and watch TV and it wasn't good for me, but when you're used to being in that environment week in and week out, you're not used to anything else.
"When other people can see something is not good for you, you can't see it because it's your everyday routine and you keep doing the same.
"I've moved to London and I'm in an apartment which is high up, there's a lot of light, I can see all the buildings in London and it makes me feel more bright and fresh in the morning and I jump out of bed!"