The study by Rethink Mental Illness found only half of Brits know the signs of it.
John Ryeland, director of the Christian Healing Mission told Premier News Hour he's glad that mental health is no longer a taboo subject.
"One of the great things is that at the moment there have been a number of high profile people talking about their struggles with mental illness," he said. "What that's done is it's created a culture where it's much easier now for folks to talk about it."
He said Bipolar disorder impacts people in various ways, but depression, heightened mood swings, and over-activity are signs people can look out for.
Ryeland urged Christians to not ignore those who struggle with mental health because almost all of them feel isolated.
"Show that God-given compassion that he's given us all," he said. "Certainly don't avoid it, thinking 'I better not think about it'. I think people long for folk to reach out to them and to love them in the state they're in."
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