Australian Medical Journal reported that cannabis accounted for 45% of hospital admissions due to drug-induced psychosis in the period between 2003-04 in this country.

New findings show that smoking cannabis puts people at risk of developing psychosis later in life. Both social and habitual users have 41% increased risk of developing psychotic illness like schizophrenia and others with symptoms like hallucinations or delusions.

The findings also showed that the increased risk for psychotic illness was relative to the dose and that stopping smoking could decrease the risk. Regular smokers were at an increased risk of between 50 % and 200 % of suffering from psychosis.

The biggest problem for researchers is to establish whether cannabis can in fact be blamed for causing mental ill-health or whether cannabis smokers with these problems were already unwell before they used the drug.

However, they claim that there is sufficient evidence to warn young people that using marijuana could increase their risk of developing psychotic illness later in life.

Although the risk is low, it is still significant. Generally, one in 100 people have a chance of developing severe psychotic illness but the risk increases to 1.4 in 100 if they had ever smoked cannabis.

Cannabis has long been considered a harmless drug with its potential long-term effects on psychosis being overlooked. It is important to warn the public of possible dangers and establish treatments to help those cannabis smokers if the problems arise.