Drugs impair self-control in addicts

Melbourne University research has shown that drug addicts find it hard to exercise self-control because part of their brain does not function effectively.

Researchers took brain scans of 30 long-term opiate addicts, and compared them with the brains of 30 non-drug addicts.

The university's Dr Murat Yucel says the drug addicts showed changes in their frontal cortex, the part of the brain needed for self control.

"It's a part that's particularly involved in helping us regulate our thoughts emotions and behaviours," he said.

Dr Yucel says the findings may change the way addiction is treated.

"It helps us understand why it is so difficult for people who have a drug addiction problem to give up, and why they continually relapse back into their maladaptive drug-taking behaviours," he said.

"We've known that drugs effect the brain for a long time, but what we haven't known is whether they cause long-term effects, and long-term harmful effects.

"What our research shows is that indeed there are some long-term effects that make the brain less efficient and more ineffective, from any where from months to potentially years."

One of the project participants, Linda, says the research could help explain why she has been addicted to opiates for more than 10 years.

"One day you're happily using, the next day you wake up thinking, 'I need it'," she said.