Painkillers known in New Zealand as "hillbilly heroin" are on the rise among Kiwi teens. The combination of prescription drugs, cough syrup and mouthwash can create a potent entry-level drug, according to drug and alcohol counsellor Jeff Morse in Waikato.

Thousands of people in New Zealand have been given methadone treatment to keep them from using heavier drugs. Many patients were addicted to painkillers than illegal drugs like heroin.

Since 2007, the number of Kiwis being treated in methadone clinics rose to 19 per cent at almost 5,000. According to experts, the increase may be attributed to more funding for synthetic drug courses.

Mr Morse said he has seen a number of people getting addicted to mouthwash with an alcohol mixture. He said mouthwash contains 5 per cent alcohol.

Prescriptions for an advanced painkiller known as "hillbilly heroin" have increased at an alarming rate despite national clamour for doctors to reduce its use.

According to health experts, opiod oxycodone is the most prescribed drug for severe and chronic pain in New Zealand since 2005. The number of prescriptions for this kind of drug rose to 183,000.

Mr Morse said oxycodone and other prescription drugs are used by people from all walks of life. He said many turn to prescription drugs out of desperation. He also said New Zealand teens used mouthwash and cough syrup if they were too young to have access to alcoholic drinks.

Mr Morse revealed that prescription drugs can be as addictive as illegal drugs and alcohol. Substance abuse is one of the leading cause of deaths in the world aside from mental illness.

A new worldwide study revealed that more people were either dying or getting sick due to mental disorders and substance abuse than from AIDS, diabetes and tuberculosis. Researchers have discovered that disorders relating to depression have the largest percentage of 40 per cent of global death.

Young girls and women over 14 years of age were usually the victims. Data taken from the 2010 Global Burden of Disease Study (GBD) showed that mental illness and drug abuse were the ones to blame for non-fatal diseases in the whole world.

The study took data from 187 countries and found mental illness and drug abuse to be the fifth biggest cause of death.