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GENE THERAPY When French doctors reported that they had successfully treated four boys for the devastating immune-system disorder known as bubble-boy disease, the news was hailed as the first clear victory for gene therapy. The researchers overcame their patients' genetic deficit by inserting a working version of a gene that enabled the boys to produce healthy infection-fighting cells. But only five months later, similar trials were halted in France and the U.S. when the experimental treatment was blamed for causing a leukemia-like illness in one child. It may be that retroviruses, used to ferry new genes into a patient's DNA, are triggering cancer by interfering with other genes. For now, the promise of gene therapy remains on hold.
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HERBS The multimillion-dollar herbal-remedy market took a hit when new studies questioned the efficacy of two of its top sellers. A six-week trial of ginkgo biloba, used to enhance memory, found that ginkgo was no better than a placebo at improving memory, learning or concentration. St.-John's-wort, which is supposed to lift your mood, didn't fare much better in a trial sponsored by the NIH. It concluded that a placebo was as effective as the herb for the treatment of moderately severe depression. (See Dr. Andrew Weil's rebuttal earlier in this issue.) A separate study found that St.-John's-wort interferes with the effects of irinotecan, a widely prescribed chemotherapy drug.
HORMONE-REPLACEMENT THERAPY For millions of women of a certain age, the news struck like a hot flash. A huge, federally funded study of hormone-replacement therapy (HRT) involving more than 16,000 women was abruptly halted when researchers discovered that long-term use of estrogen and progestin was not lowering the risk of heart disease and stroke in postmenopausal women, as had been promised, but raising it, along with the risk of invasive breast cancer and blood clots. What women taking hormones to treat acute symptoms of menopause should do now is unclear. The study showed that there are real risks from long-term hormone replacement, but it didn't say anything about going on HRT for a few years to get over the most acute symptoms of menopause. HRT is still the best treatment available for relief of night sweats, hot flashes and mood swings, and for many women the benefits of short-term treatment will continue to outweigh any uncertainty about the risks.
HYPERACTIVITY Nobody knows what causes the impulsiveness and fidgetiness of attention-deficit/hyperactivity disorder (ADHD), but a brain-imaging study provided further evidence that the disorder is biologically hard-wired. A federally funded 10-year study of nearly 300 children ages 4 to 19 found that the brains of kids diagnosed with ADHD were 3% to 4% smaller in volume than those of normal children. While smaller brains don't necessarily mean lower IQs, brain size does appear to affect the severity of ADHD. In general, the smaller the brain, the greater the symptoms.
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