Scientists at the University of Edinburgh studied the brains of 34 deceased intravaneous drug abusers of heroin and methadone and compared them to the brains of 16 young people who were not drug users. Their examination revealed brain damage in the drug abusers normally seen in much older people.
The damaged nerve cells were in the areas of the brain involved in learning, memory and emotional well being, and were similar to damage found in the early stages of Alzheimer's disease.
"Our study shows evidence of an increased risk of brain damage associated with heroin and methadone use, which may be highest in the young, when individuals are most likely to acquire the habit" said co-author Jeanne Bell Professor of Neuropathology. "We found that the brains of these young drug abusers showed significantly higher levels of two key proteins associated with brain damage."
"In a previous study we found out that drug abuse causes low grade inflammation in the brain. Taken together, the two studies suggest that intravenous opiate abuse may be linked to premature ageing of the brain," Bell said.
Heroin and Methadone Cause DamageThe average age in these two groups in the study was only 26 years and included some drug abusers as young as 17.
"Tau protein, which in its soluble form is essential for communication and transport within brain cells, had become insoluble in some cells, causing nerve cell damage and death in selected areas of the brain," the authors reported. "Other nerve cells showed an accumulation of the amyloid precursor protein, which suggests that protein transport had been disrupted and the nerve cell functions affected."
Severe Nerve Cell Damage"This study shows that drug abuse can lead to a build up of proteins which cause severe nerve cell damage and death in essential parts of the brain. This is very worrying as there are strong indications that drug use in the UK, in particular opiates like heroin and methadone, has continued to rise in recent years" says Professor Bell.
"The drug abusers we looked at in the study sadly died at a young age, but there are many others who don't realise the long-term effects that these drugs may be causing."
Source: S. N. Ramage, I. C. Anthony, F. W. Carnie, A. Busuttil, R. Robertson, J. E. Bell, "Hyperphosphorylated tau and amyloid precursor protein deposition is increased in the brains of young drug abusers," Neuropathology and Applied Neurobiology, June 2005.