Houston "thanks everyone for their support and prayers," publicist Nancy Seltzer said in a statement Monday. She declined to offer any further details.
Houston, 40, admitted in a December 2002 television that she had abused drugs in the past, but told interviewer Diane Sawyer on ABC's "Primetime" that she had gotten beyond that time through prayer.
Houston's husband, R&B singer Bobby Brown, was sentenced to 60 days in jail in late February for violating probation. One of the violations included a December misdemeanor battery charge for allegedly striking Houston, leaving her with a bruised cheek and a cut inside her lip.
In January 2000, Houston left behind a bag at Keahole Kona International Airport in Hawaii that allegedly held less than half an ounce of marijuana and three partially smoked marijuana cigarettes.
In 2001, a petty misdemeanor drug charge relating to the incident was dismissed against Houston after a drug counselor filed an assessment with prosecutors stating that Houston did not require treatment for substance abuse.
Brown and Houston have been married since 1992 and have a 10-year-old daughter, Bobbi Kristina. The couple owns a home in Mendham Township, N.J.