Jared O'Mara is 'taking time out' to receive professional help to deal with mental health issues and "issues regarding self-medication", he as announced.
The Independent MP - who took the Sheffield Hallam seat for Labour from former deputy prime minister Nick Clegg in 2017 - made the announcement on Twitter days after a disgruntled former employee hijacked his feed for a dramatic online resignation.
Responding to criticism about his conduct, he said: "In a few weeks, I will be making a follow-up statement regarding my position, until then I will be taking time out to receive professional help to deal with my mental health and personal issues regarding self-medication."
He said: "I would like to start by apologising to my family, my friends and my constituents. I have not been honest with you about the depths of my depression and self-loathing.
"When I started this job in 2017 I was a different man: a confident and passionate man that wanted to help others.
"Sadly, I was unable to do that because very quickly I was bullied and mistreated in a harsh and unforgiving environment and that led me to be weak."
Mr O'Mara used his statement to blame Labour leader Jeremy Corbyn for how he had been treated by the party.
He had the whip withdrawn after apparently sexist and homophobic comments emerged which he had posted on social media years earlier but was readmitted to the party after receiving a formal warning.
But, last year, Mr O'Mara resigned from Labour, saying he had been "made unfairly to feel like a criminal", and now sits as an independent.
At the time of his resignation he revealed that he had made three suicide attempts at the height of the furore and described himself as "the first autistic MP in our history".
On Thursday he said that discrimination he has suffered has led to the deterioration in his mental health to the point at which he recently "suffered a delusional episode".
He said: "I want to become a better person again; like I was.
"I feel I've become unrecognisable and I want to make amends. I need treatment for my mental health and rest first though. "
A Labour Party spokesperson said: "We take the welfare of our MPs very seriously and, while Jared is no longer a Labour MP, we are concerned for his welfare and we have continued to provide support to him, and will continue to do so."
