The wall programme shows fully-grown adults dressing up as babies, having their nappies changed and being cared for as an infant.
It SHOWS adult babies attending fake nurseries in the UK and US, alongside other adults — including their SPOUSES — who pretend to be their mums and dads.
One adult baby, Derek, says: "When I put a nappy on it takes me back to that time when I had no stress."
Many claim their desire to regress to an infantile-state is not sexual but about escaping the pressures of being a grown-up.
Derek adds: "As soon as you mention adult baby, they all think it's something to do with children and it's, you know, paedophiles.
"We don't want to be with children. We want to be the child."
In the trailer for the Channel 4 film — entitled The 15-Stone Babies — the wife of an adult baby says: "I think in most wives there is a bit of a mother bond with her husband."
Another woman is seen showing the camera crew around her play rooms, stuffed full of oversized toys and objects.
When asked how old she is today, she replies: "Um, I don't know. Daddy might know."
The film reveals how adult babies are now connecting through social media, with one claiming there must be "a good 200,000 to 500,000 maybe in just, the US and the UK".
Others admit their strange fetish makes them feel lonely and alienated from others.
One male adult baby says: "They just think I'm weird and a freak and never want to talk to me again."