At least one cannabis factory is being shut down by police in Scotland every week, one of the country's most senior officers has warned.
The home-grown drug is much stronger than imported cannabis
Graeme Pearson, head of the Scottish Crime and Drug Enforcement Agency, said more than 60 industrial-level cannabis farms had been raided in the last year.
Mr Pearson revealed there had been virtually no major cannabis production in Scotland until 12 months ago.
He said the illegal factories were being set up by organised crime gangs.
Mr Pearson said workers in the factories, which are often set up in residential areas, were frequently kept locked inside like slaves.
The factories produced super-strength cannabis, which Mr Pearson said he believed was causing an increasing number of young people to suffer mental health problems.
Recent estimates have suggested that about 60% of cannabis smoked in Britain is now home-produced, compared with only 11% a decade ago.
The UK government downgraded cannabis from a Class B to a Class C drug in 2004, but has recently indicated it is considering reversing that decision.
The original reclassification was criticised by many experts, who said it sent out the wrong message about the potential dangers of using the drug.
Mr Pearson said: "It has gone from virtually no production just over a year ago to over 60 such productions being discovered by forces across Scotland in the last nine months.
"What we have got is these types of developments within houses, factories, garages and so forth.
"In a very high number of them we have got Chinese or Vietnamese people who are locked in the premises, kept sleeping on the floor amongst mattresses with no visible means of support. They are virtually slaves within the production mechanism."
Many of the factories contain up to 1,000 cannabis plants and are capable of producing £100,000-worth of cannabis, making production in Scotland worth at least £7m a year.
He said the trend of factories being set up to mass-produce cannabis was one that had spread around the world in recent years before finally arriving in the UK.
He added: "Australia saw the trend, Canada saw the trend and now we now have it in the UK, where organised crime gangs are focusing on the industrial production of cannabis in order that they can up the potency of the product and therefore have a more marketable product.
"Doctors have done experiments and gathered statistics which have shown that more people are coming to the attention of the health service because of difficulties with mental health.
"I don't think it is a problem that law enforcement alone can deal with."
Carla Ellis, project manager for the Crew 2000 drugs advice group, said more research needed to be done on the potential links between mental health and cannabis use.
She added: "I think we have to remind ourselves that the vast majority of people who smoke cannabis will not have any problems associated with their use.
"They will probably use it for a very short period of time and they will probably stop as the consequences of their use clash with their lifestyle.
"Many people do see it as relatively harmless compared to other drugs."