Six out of 10 people (62%) in Britain have had at least one time in their life where they found it difficult to cope mentally, according to a survey published today.
Mental health charity Together said the figures showed there should be an end to a "them and us" attitude to the topic.
The research, commissioned to launch the charity's annual Mental Wellbeing Week, found that 70% of people had suffered stress, 59% anxiety and 55% depression.
These were the three most common difficulties encountered by the public.
Three in 10 (32%) said they had been worried they were "cracking up" at one point or another.
Liz Felton, ex-psychiatric nurse and the charity's chief executive, said: "This research shows that mental health and wellbeing is an issue relevant to most people, not just those with diagnosed issues.
"We hope the results go some way to try and reduce the 'them and us' mentality about the topic that can lead to stigma, and perhaps prevents some people from seeking help, or talking about what they're going through when they need to."
The research also revealed that of the people who admitted to experiencing difficulties, 69% had taken at least one step that saw them try to isolate themselves from the outside world or mask how they were feeling, rather than facing up to what was happening.
Matthew Hyndman, who has had difficulties himself, and been supported by the charity, said: "I was bullied at university and it put me into a downward spiral to the point where most of my days were spent in the house staring at the television.
"I now realise this is the worst thing you can do, because the more isolated you become, the harder and more unimaginable it seems that you will ever have the courage to enter 'normal' life again. It was like a vicious circle, but one I broke in the end."
Commenting on the findings, Care Services Minister Phil Hope said: "Other debilitating conditions like cancer or heart disease prompt sympathy and understanding. But mental health is all too often treated as taboo.
"As this survey makes clear, many of us will be affected by mental health problems at some point and that is why we are bringing forward a radical new approach which includes the national roll out of our successful talking therapies programme, NICE guidelines, new action on suicide prevention and a plan to tackle the stigma shrouding mental illness.
"The recently launched NHS Stressline also offers practical and emotional support for people suffering from anxiety, depression and stress."
People seeking advice about wellbeing were urged to visit http://www.together-uk.org
:: The survey of 2,000 adults was carried out online by YouGov plc between February 15 and 17.Reuse content