Henry Dennistoun "Dennis" Stevenson of Coddenham, who has suffered from depression in the past, said there is still huge stigma attached to mental health problems.
Stevenson told Channel 4 News he started to suffer from anxiety and depression in the mid-1990s, at which point he felt like he was going "completely crackers and started seeing things," The Daily Telegraph reported.
Last year, Stevenson, a member of the House of Lords, sponsored a bill to make discrimination on mental health grounds illegal, but it failed in Parliament. However, a revised version this year has received government backing, Stevenson said.
The bill would abolish a law currently barring people treated for severe mental health problems from being members of Parliament, company directors or school officials, or jurors, Stevenson explained.
Enacting it would mean "basically getting rid of the Salem witches aspect of mental health discrimination," he said.