The husband of Aintree Racecourse chairman Rose Paterson said he hoped a new charitable trust in her memory could save other families going through the “extraordinary anguish” of suicide.
The mother-of-three, 63, was found in woodland near their home on 24 June.
She had a long association with Aintree and a race at the Grand National Festival has been named after her.
The Rose Paterson Trust will be launched at the course on Saturday, the day of the Grand National.
Owen Paterson, Conservative MP for North Shropshire, said it would raise funds to support suicide prevention projects.
“We will never know definitively why Rose did this but the impact on us is absolutely terrible,” he said.
“Never a minute goes by when I do not think ‘how on earth did I not notice?’
“I was married to her for 40 years, that is a long time and we never had an inkling of this.”
Mr Paterson said his wife appeared to have a happy, fulfilling life but it did not tell the whole story.
“If we can just help stop just one family going through the extraordinary anguish that we are currently going through and will continue to for many years, then we might have done some good,” he said.
The trust also plans to campaign to get changes in national policy in a bid to reduce the frequency of suicide.
The MP, a former Northern Ireland Secretary, said he was keen to shape government policy around mental health issues, including looking at the role of websites.
“I know Rose was looking at websites… The internet is a very wonderful thing, it is extraordinary at disseminating information but it can cut the other way too.”
Mr Paterson has also been appointed vice-chairman of the all-party parliamentary group on suicide and self-harm prevention.
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