Such was the case with "beta-blocker blues," a syndrome of fatigue and mild depression sometimes associated with regular use of a popular category of heart drugs called beta blocker.

The next day, they saw the pictures again but half were given the drug propranolol, a beta-blocker commonly used to treat heart disease.

The beta-blocker blood pressure drugs atenolol (Tenormin), celiprolol, and talinolol.