Matua Raki National Addiction Workforce Development director Raine Berry said a Ministry of Health goal was to "heighten services and clinicians' awareness and skills in the area".
"The whole project around co-existing problems has been based on the ministry's goal to develop the capacity of mental health services and addiction services to work with people with both problems, which is between 50% and 70% of the population of people who present to addiction or mental health services," she said.
She helped host a workshop on the subject during the first day of the Te Ao Maramatanga New Zealand College of Mental Health Workers conference in Dunedin yesterday.
"We really have failed, largely, in working effectively with people with co-existing problems ... These people have fallen between the cracks [and] it really has not been good enough," she said.
A "significant system change" was required to ensure mental health and addiction workers were able to assess and make effective management plans to help people with co-existing problems.
In order to bring change, mental health and addiction workers needed to be aware of a client's bigger picture.
Many services would dismiss aspects of a person's health because it was not considered their area, or a broader assessment and diagnosis was not carried out.
"All people should be screened for mental health and alcohol or drug problems," Ms Berry said.
However, keeping up with substance-use trends remained a challenge in the sector, especially as the recession had put workplace development in "danger".
"In terms of the addiction area, we are faced with new drugs that come on the scene, like Kronic," Ms Berry said.
Keeping up with substance-use trends and being aware of the effect they could have on a person's stability was important.
Alcohol remained the largest substance-abuse problem in New Zealand, but people were now drinking and smoking Kronic too, often increasing the negative impact on their health, she said