If a recovering cocaine addict claims he no longer craves the drug, you cantell if he's lying by looking in his eyes. Researchers at the Veterans Administration Medical Center (VAMC) in East Orange, New Jersey, are testing a machine, the electroretinogram, that tracks how quickly certain cells in the eye react to colored flashes of light. When these cells respond sluggishly to blue flickers, it might be a sign that there's a shortage of the neurotransmitter dopamine in the brain. And a mental dopamine drought, in turn, may mean cocaine cravings are intense.
Researchers hope the device may help doctors tell when recovering addicts are biologically vulnerable to relapse. For such individuals, suggests the VAMC's David Smelson, Psy. D., doctors could nip a relapse in the bud by prescribing drugs that boost dopamine.
