A bill being introduced in the Dáil later is being seen as an important first step towards the full regulation of cannabis.
People Before Profit TD Gino Kenny is set to introduce the bill to end the criminalisation of cannabis for personal use.
Eddie D'Arcy from Youth Workers Against Prohibition said this should help some young people.
"We're supporting Gino's bill this morning; we think it's an important first step towards the full regulation of cannabis," he said.
"The 150 or so youth workers who have signed this letter, calling for the regulation of cannabis, we're very much aware of the consequence of a criminal record for cannabis possession has on young people's life in terms of employment, travel, insurance, education, housing".
Mr D'Arcy said for many this would eventually lead to imprisonment "because they get drawn into the criminal network that supplies drugs to these young people."
"We don't think decrim[inalisation] itself is going far enough... whereas it will protect people who use cannabis from acquiring a criminal record, it will still require the purchase of cannabis from a criminal network.
"We think there's something unsavoury and unethical about that".
Brendan Kelly, Professor of Psychiatry at Trinity College Dublin, said there needs to be a middle-ground.
"We know that cannabis can affect mental health badly," he said.
"The evidence is now very, very clear that it increases risk of schizophrenia, increases risk of self-harm.
"Heavy cannabis users report more thoughts of suicide, the higher the use the greater the risk - the scientific and medical evidence is now overwhelming."
However he said the approach to the drug does need to change.
"We need to separate two questions: is cannabis bad for mental health - and the evidence is now very clear it does present a risk - but the second question's a tiny bit different [which] is what do we do about that?
"Certainly keeping cannabis as criminalised as it is doesn't seem to be working, so we do need to think differently."
Prof Kelly said evidence suggests decriminalisation will not remove the black market.
"Decriminalisation is a reasonable thing to consider, but we do need to be realistic," he said.
"The first message is that cannabis presents a risk to mental health - the second message is what has happened where it is decriminalised?
"The evidence is very clear that the black market continues for stronger products, alongside the legal market.
"So the idea that discrimination will stop the black market is simply not supported by the evidence."
He said a "health response and a social care response" might be the best way to go.
"Criminalising people who possess small amounts... really serves no benefit whatsoever," he added.