Amphetamine use linked to brain lesions

OCCULT brain abnormalities that could lead to cognitive decline, and even an increased risk of stroke, may be present in as many as one in five amphetamine users, new Australian research suggests.

Using magnetic resonance imaging (MRI), Perth researchers found 20% of the serious and recreational amphetamine users included in their small pilot study had an occult brain lesion.

The most common lesion was an unidentified bright object in the frontal lobe.

“Whether or not these unidentified bright objects are associated with long-term clinical effects is unknown, but our finding supports the possibility of amphetamine use being a risk for cognitive decline, and perhaps an increased risk of stroke,” the researchers said.

Professor Dan Lubman, director of Melbourne’s Turning Point Alcohol and Drug Centre, said the findings indicated that more work was needed to determine whether chronic amphetamine use was linked to brain injury.

“Further exploration or explanation of the unidentified bright objects found by the researchers in the frontal lobe is needed before we can confirm what impact chronic use has on the brain,” he said.

A total of 30 people were included in the pilot trial among patients attending the emergency department at the Royal Perth Hospital with an amphetamine-related presentation.

Most were young men (mean age, 26.7 years), and more than three-quarters were serious drug users.

Alcohol, marijuana and ecstasy were the most commonly used drugs, followed by crystal methamphetamine and amphetamine.

As well as problems with mood and concentration, many reported general health and memory problems. Almost half had a history of depression, nine reported having been admitted to a psychiatric hospital, while seven reported a history of psychosis.

Professor Lubman, who is also Professor of Addiction Studies and Services at Monash University, said that the prevalence of psychotic symptoms is known to be about 11 times higher among heavy methamphetamine users than among the general population in Australia.

“This study, while interesting and consistent with those findings, does not include a control group. The participants also have a high rate of comorbid problems, especially mental health problems.”

Researchers also noted that it was difficult to attribute causation because these patients were often users of multiple drugs.

However, they said that because their findings were congruent with evidence that amphetamines cause brain injury, they could have public health implications.

MJA 2010; 193: 266-268
Posted 6 September 2010