"So I left the bed," he said.

"I can buy another bed.

"I can't get copies of those things anywhere."

Those things are mostly relics of his professional life – including old resumes, job applications and minutes from board meetings –that fill about 10 plastic storage boxes and 50 shopping bags crowded into the bedroom of his Ngunnawal share house.

Mr Kroschel tends to hoard. And given between 400,000 to one million Australians suffer from hoarding disorder, he's not alone.

For years the prospect of sorting and chucking out Mr Kroschel's papers has proved a task too hard to face, too emotionally difficult to process and too overwhelming to complete.

"I have tried so many times to go through and edit what's in those boxes but every time I go to do it I get delayed by all the emotional stuff," he said.

"When I find notes from board meetings from years ago I remember the meeting and all the people who were there at the meeting.

"That's where I get stuck, I can't seem to get past it.

"There are so many boxes and it's all too huge for me. I can try to start and I can sit there for hours remembering."

He said his possessions were evidence of the lived he'd lived and his professional achievements.

"These things are important. They're almost part of my identity."

Clinical psychologist Christopher Mogan, a hoarding expert from The Anxiety Clinic in Melbourne, said the "hidden disorder" had only recently been recognised as a condition and was far more common than most realised.

Dr Mogan, who will speak in Canberra on Monday, said hoarding was "a high prevalence disorder" which affected an estimated 2 to 5 per cent of the population.

In comparison, about 1 per cent of the population has schizophrenia, while about 2 per cent are affected by obsessive compulsive disorder.

"It's like a sleeping giant really and it's well known as a secret disorder," he said.

"People can have quite a well-functioning life but no one is ever invited to their home.

"I'm sure that the leafy green suburbs of Canberra would have their comparable share of hoarders.

"It goes across all socioeconomic groups."

Dr Mogan said hoarding disorder was characterised by an inability to stop accumulating goods and a compulsive need to gather objects, that interfered with their life and the lives of others.

Hoarders also became overly attached to things and weren't able to get rid of objects other people would likely throw away.

Taking an item without their permission would be "like ripping people's hair off or tearing people's fingernails out", Dr Mogan said.

"The idea of a category of hoarders is not helpful. It's better to look at it as a dimension."

While people who liked to collect items were able to organise their collections in a specific way, hoarders were characterised by disorganisation, mess and clutter.

"And in some cases, deteriorated conditions such as appliances not working or infestation with mice or rats, or toilets or bathrooms that don't work, leaking roofs."

Mr Kroschel will run a support group for Canberrans with hoarding problems, through Woden Community Centre, based on the American Buried in Treasure program from next month.

He will work through the 20-week support program with other hoarders and said he had "specific knowledge of what it's like to have stuff you can't get rid of".

"I haven't been able to do it alone and unless I understand the why, I'll never be able to."

Group members will be asked to bring along items they have collected to speak about what they mean to them and why they found it hard to let go.

He hoped the program would help group members declutter their lives, even if that meant clearing one bookshelf.

Dr Mogen said cognitive behaviour therapy had proved effective treatment for hoarding, which was often associated with trauma and influenced by genetics.

"I found from my research that people were more likely to be hoarders who had an uncertainty about their identity and had an impression there wasn't a lot of warmth in their early family life.

"It was like some kind of attachment disorder; a person who has some kind of hoarding disorder uses things as a sort of symbolic link."

Dr Mogan said hoarding raised safety concerns linked to falls, fire risk and hygiene and required a multi-agency response.

"It's early days in terms of trying to understand the problem and that's why we've got to have this conversation. It's not about demonising people with hoarding disorder, but trying to understand them."

Dr Christopher Mogan will give a free lecture, Collector? Keeper? Hoarder?, from 6.30pm on Monday, June 15, at the Theo Notaras Multicultural Centre, 180 London Circuit, Civic.