Papua New Guinea's mental health service says most of its patients have a history of smoking marijuana, and the drug is also affecting the mental health of school students.
The police in Papua New Guinea have said they lack the resources to address the increasing availability and use of marijuana, which has been fuelled by an international syndicate supplying the drug to the Australian market.
Dr Uma Ambi, the Health Ministry's principal mental health advisor and President of the Psychiatric Association, says most of the chronically ill patients they treat have been exposed to marijuana.
She says they're also seeing the impact of the drug on school students
"Most of the time the youngsters in the school age groups when they are walking around they abuse so much, and they come with the motivational syndrome and their performance at the school drops tremendously and they lose hope and are helpless."
Dr Ambi says many of the students drop out of school, which will affect social and economic development in PNG.