Mental health statistics show that cannabis smokers are at an increased risk of suffering from depression, anxiety and psychosis as compared to stimulant drug takers.
A new national report has shown that dope smokers display higher rates of several psychological symptoms when visiting their doctor.
Of patients who mentioned cannabis use to their GP, 48 per cent had a psychological problem, including 19 per cent with depression and nine per cent with psychosis. Six per cent had anxiety.
Director, professor Jan Copeland, said that the results confirm the dangers of the drug.
"It was unexpected, given what we hear about amphetamine-related psychotic symptoms, but it goes to show what a terrible impact cannabis is having on users,'' the Herald Sun quoted Copeland, as saying.
"The delusions, hallucinations and paranoia can be very distressing and people are feeling it,'' Copeland added.
The results, in data collected from 1000 randomly-selected GPs, also revealed that mentioning cannabis use to a doctor was very rare, with the drug named in just 19,000 consultations nationwide each year.
The report found that the users were more likely to be male, young, unemployed or on a low income and indigenous.
"The low numbers are a major concern given the sheer number of users and the effects we know that use is having,'' Copeland said.
Studies show most people do not experience major problems with occasional use but heavy use can lead to depression, memory loss, lung damage, low sex drive and even brain shrinkage.