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Drug Dependency: A New Sort of Thinking Cap

News from the Johns Hopkins Department of Psychiatry and Behavioral Sciences

Dr. Mintzer

Dr. Miriam Mintzer

Anesthesiologists know how useful a well-timed benzodiazepine can be: It chases away patients presurgery fears and brings on a blessed amnesia for what goes on in the OR. And many psychiatrists trust a short course of the pills to dim memory enough after a traumatic event to keep acute anxiety from sliding into PTSD.

"But," says Miriam Mintzer, "that very effect or other ways that drugs can alter thought processes may get in the way of therapy for people who abuse them." So Mintzer, a cognitive neuroscientist, has joined a move to increase awareness of the scope of cognitive changes that drugs with abuse potential can bring, subtle as well as obvious.

Being impulsive, for example, is a common behavior tied to long-term drug abuse, Mintzer says, "and, presumably, it makes it more difficult to stop. The question is: Could we target it as part of treatment?"

Patients quickly learn what they need to do in the outside world to resist temptation, she explains, but they don't do it, especially in an environment booby-trapped with pill bottles or other cues. "Training them to recognize and inhibit their automatic response could make a difference," says Mintzer, who cites studies of successfully schooled impulsive children.

Support for such potential help, though, lies in the lab. While years of researching what makes people dependent on a substance are finally bearing fruit, knowing the fine cognitive effects the changes in attention, memory, decision-making abilities of opioids, marijuana, cocaine and amphetamines, for example, has lagged behind. Even work on otherwise well-studied alcohol and benzodiazepines lacks detail that might help fine-tune therapy.

Much of Mintzer's work has focused on the "benzos," teasing out cognitive effects of that drug family in healthy volunteers. Her research sparks interest in light of collected observations of chronic benzodiazepine abusers. Both have problems in encoding new information. The drug's use doesn't impair your ability to retrieve memories of past events (episodic memory), she says,  but to lay down new ones.? Added clout has come from a PET scan study with Hopkins radiologist colleagues confirming that brain areas specific for memory-encoding are indeed sluggish.

What might that mean for patients who describe memories for events as "a fog" or "a blur"? Often-used tactics like cognitive behavioral therapy, which rely on remembering flawed ways of thinking and "encoding" better ones, may need adapting for drug abusers, Mintzer says.

Recently, she's turned to cognitive science's newest baby, metacognition --- an awareness of the state of one's own thinking. "It's a particular problem with the benzodiazepines," she says. "After just a single dose, people often have no idea how much their memory and performance is off." Again, Mintzer is laying a research base with studies on healthy volunteers.
Improved metacognition could literally save lives: "If you know you're impaired, you might not get in your car," she says. "Also, heightened metacognition is important generally in psychiatric disorders. It helps patients get well."

For more information, call: 410-550-0529.

Winter 2008 IndexHopkins Newsletter Archive