Researchers studying the effects of cocaine use are finding new evidence that the drug can cause lasting chemical changes in the brain and trigger panic attacks and episodes resembling seizures long after drug use has stopped.
Electrical studies show curious brain wave patterns in patients who suffer overwhelming attacks of panic and anxiety after a long history of periodic cocaine binges.
In many ways, the researchers say, those patterns resemble brain-wave tracings created by the distorted electrical signals thatbrain cells emit when epilepsy patients undergo seizures. The same anti-convulsive drugs most often prescribed for epilepsy also seem to be most effective in smoothing the daily lives of one-time cocaine users who find themselves frequently gripped by unreasoning panic, the researchers say.
Dr. Alan Louie, a psychiatrist at the University of California's Langley Porter Psychiatric Institute in San Francisco, says about 25 percent of the patients who come to the institute's "affective disorders clinic" because they are suffering from periodic bouts of severe panic describe a history of heavy cocaine use.
one study of 10 of those clinic patients, the panic attacks continued for as long as seven years after the patients stopped using cocaine, Dr. Louie said.
That persistence led Dr. Louie and his colleagues, Dr. Richard Lannon and Dr. Terence Kettner, to conclude that long-term periodic use of cocaine had altered the brain chemistry of the patients and made them so sensitive that the panic could be triggered by even the slightest stimulation.
The Langley Porter study was published in a recent American Journal of Psychiatry.
6* There, Dr. Louie and his colleagues de
scribed one 25-year-old woman who had "snorted" cocaine at least once a week for three years, abused amphetamines and as a teen-ager had been a heavy user of LSD, marijuana and alcohol.
She suffered repeated bouts of intense fear, abnormally rapid heartbeats, lightheadedness and shortness of breath. Whenever an attack came, she saw distorted shapes, and kaleidoscopic patterns seemed to cover the walls around her.
At Langley Porter, psychiatrists tried treating the woman with one of the common drugs that combat depression, but they only intensified the panic attacks.
BFinally, the doctors tried an anti-convulsant drug used to control partial seizures in epilepsy. The panic attacks and the distorted vision all stopped, and a year later there were no more symptoms.
According to the report's authors, similar episodes of panic or anxiety may occur in nearly two-thirds of all cocaine users.
Among the drug abuse patients they have seen at Langley Porter, the symptoms have developed only among those who vTC used cocaine for long periods -- anywhere from one to six years -- while the panic attacks persisted for months or even years after the people stopped using the drug.