Researchers agree that drug addiction is a physical illness, not a weakness of will or lack of moral character, and the industry and government researchers are targeting the potential treatment market. NIDA is also testing drugs for opiate addiction, including mecamylamine, lofexidine and buprenorphine. Depression, which affects an estimated 19 million Americans, is another big market. Many of the drugs affect levels of serotonin, an important neurotransmitter, or message-carrying hormone, linked with mood. Sanofi-Synthelabo is investigating the potential of a reversible monoamine oxidase inhibitor called befloxatone.
Monoamine oxidase breaks down serotonin, so inhibitors of the enzyme make more serotonin available.
It targets the amyloid plaques that mark the incurable brain illness. Novartis is in Phase II safety and efficacy trials with NDD 094, which may regrow brain cells that produce acetycholine, a neurotransmitter involved in memory. One group of drugs, the cannabinoid receptor antagonists, are building on research that examined the effects of marijuana on the brain. Sanofi-Synthelabo is testing SR 141716 against Alzheimer's, obesity and schizophrenia, which affects two million Americans. Research in animals has shown that anandamide, a chemical similar to cannabis, puts the brakes on dopamine, the neurotransmitter associated with schizophrenia.