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Rats on Ritalin grow to be despondent swimmers

Preadolescent rats given the popular drug Ritalin are more likely to show signs of depression in adulthood, according to a Harvard study.

The study suggests that stimulants, at least in the normally developing brain, can have unsuspected effects in adulthood. The findings also underscore the importance of an accurate diagnosis for attention-deficit hyperactivity disorder, often treated with Ritalin.

William Carlezon, director of McLean Hospital's Behavioral Genetics Laboratory and associate professor of psychiatry at Harvard Medical School, presented the findings at the annual meeting of the American College of Neuropsychopharmacology in Puerto Rico.

Carlezon said that because there are no animal models for the attention-deficit disorder the young rats in the Harvard study were normal. Experts say that in many people the disorder goes unrecognized and untreated and that others are misdiagnosed.

"These are important issues," said Dr. Peter Jensen, director of the Center for the Advancement of Children's Mental Health at Columbia University Medical Center. "We know that depression occurs more often in adults with ADHD. What we don't know is whether it's because the disorder wasn't treated when it should have been, or was treated and the depression is a consequence of treatment, or it's a result of ADHD itself."

The animals were exposed to Ritalin during the same developmental stage as a human between ages 4 and 12. The animals spent 15 days on the stimulant. Otherwise, they grew up with untreated littermates.

In adulthood, the animals were given tests to tap the brain circuits thought to trigger symptoms of the disorder - hyperactivity, impulsivity, difficulty focusing. The stimulants work on regulating the brain chemical dopamine, involved in learning, attention, motivation and reward.

The tests showed "the animal's brain reward system is altered" by drug treatment in preadolescence, Carlezon said.

In one experiment, the animals were placed in water and forced to swim to safety. The treated animals gave up much more quickly, scientists said - an indication of depression.

Other studies also showed the brain's reward system was not working properly. The animals seemed uninterested in working for rewards that would normally be pleasurable.

KAMPALA, Uganda - Doctors and AIDS activists in Africa are worried governments may halt use of an AIDS drug that has protected thousands of babies from HIV infection in reaction to concerns about the drug's testing and effect on pregnant women.

Dr. Saul Onyango, a medical officer involved in the testing, said Thursday that officials were worried about the fallout from Associated Press reports this week about how testing of the drug nevirapine at Uganda's Mulago Hospital failed to meet international standards.

Research found that pregnant women who take the drug once to inhibit passing HIV to their babies may develop resistance to it.

MIAMI - A device that automatically detects early symptoms of congestive heart failure has been implanted in patients in the United States this month.

When fluid levels around the heart get too high, they can interfere with a normal heartbeat and cause death. The InSync Sentry device monitors the amount of fluid in the chest. If there is a buildup, doctors can prescribe medication to reduce it.

One of the devices was implanted in a patient at the University of Southern California last Friday. A second one was implanted Monday in 70-year-old Antonio Comandari at Miami's Jackson Memorial Hospital.

The device, built by Medtronic Inc. of Fridley, Minn., costs about $30,000, lasts five to seven years and should be available for widespread use by February.

CHICAGO - Sweet alcoholic drinks aggressively marketed to young people are luring troubling numbers of teens - especially girls - to engage in underage drinking, the American Medical Association said Thursday.

A nationwide AMA poll of 741 youngsters aged 12 to 18 found that 31 percent of girls and 19 percent of boys had consumed drinks some call "alco-pop" or "malternatives" in the past six months.