Reports of increased risk of depression and suicide are dimming the future prospects of drugs designed to treat addictions to alcohol, tobacco and other drugs, the Associated Press reported April 22.

Development of anti-addiction drugs has gained increased attention from pharmaceutical companies in recent years, but problems associated with drugs like the antismoking medication Chantix -- a Pfizer drug linked to numerous suicide attempts -- has led to concerns that the drugs block feelings of pleasure as well as craving for drugs.

One possible solution would be to limit prescriptions of these drugs to patients who have no history of depression. The FDA says a link between Chantix and depression is "increasingly likely," but Pfizer officials and other experts say it's hard to determine a cause-and-effect relationship.

"Psychologically, just giving up this 'friend' that they've had many years in their life can be depressing," said Geoffrey Williams, co-director of the Greater Rochester Area Tobacco Cessation Center and a paid speaker for Pfizer. "The risk-benefit ratio is still very much on the side of use of the medication. The alternative, smoking, is extremely highly risky."

Still, the side effects have put a damper on hopes of developing "super pills" for addiction treatment. "It certainly diminishes my enthusiasm," said Mark Egli, co-director of medication development at the National Institute on Alcohol Abuse and Alcoholism.