One East Coast individual with a substance addiction has been receiving the invalids benefit for 18 years.
Under welfare reforms passed in July, sickness and invalids benefits were repackaged to become Jobseeker Support and Supported Living Payment.
Beneficiaries on Jobseeker Support can be exempt from work obligations if they have a significant injury or health condition, but must seek at least 15 hours' work each week if their health practitioner determines they are capable.
Those deemed capable of work are now forced to take drug tests if potential employers ask for it.
Hawke's Bay registered social worker and addictions specialist Stephen Wright said the use of synthetic cannabis had increased in the past decade.
"There's been a huge turn to synthetic highs - it can't be detected for workplace tests so we see people lining up."
Adult sex shops were the only place to buy the products, so addicts would be waiting for the shops to open at 9am, he said.
"You see people sitting in their cars sweating and truck drivers clearly at work.
"They race in and get their synthetic high."
Drug addiction was not limited to the poor and underprivileged, he said.
"Alcohol and synthetic highs are widely available, legally prescribed and over-the-counter medications are also being administered to the community's brightest and respected members.
"These drugs show up on the nightlife scene, work environments, school grounds, sports games.
"The legality and acceptability of these drugs have turned their abuse into a devastating epidemic."
Addiction was not weakness in an individual, there were many pre determining factors and addicts used drugs as a way of coping with the world and themselves, he said.
Substances had a powerful impact on a person's body and feelings however these effects did not on their own cause addictive problematic behaviours.
The way a person interpreted and responded to the impact of a drug was at the core of addiction, he said.
Beneficiary Advocacy Federation spokeswoman Kay Brereton said substance abuse covered a broad range of problems, from those addicted to painkillers prescribed for a medical condition, to those with an illegal drug habit.
Long-term addicts were often using substances to cope with past trauma and could not become work-ready in a set timeframe.
However, "semi-medical" staff at the Ministry of Social Development (MSD) had begun "second guessing" doctors' assessments and asking them to change their medical opinion in order to get beneficiaries back into work, she said.
While there was nothing wrong with MSD seeking more clarity on doctor assessments, it had to be transparent.
Work and Income associate deputy chief executive Liz Jones disputed the claims.
"Clients need a medical certificate from a GP if they are unable to work because of a health condition or disability, so we are certainly not discouraging doctors from writing medical certificates."
But she said staff regularly contacted doctors to clarify information provided on medical certificates or confirm benefit eligibility or work capacity.
Deputy chief executive Debbie Power said clients with a substance addiction had "deferred work obligations" until determined ready for work.
They were encouraged to access funded detoxification, rehabilitation or counselling programmes. APNZ
