Lab Report: Health, Science and Medicine

MENTAL HEALTH

Pot and Schizophrenia: A Dangerous Mix

A mind is a terrible thing to scramble. Doctors studying schizophrenia have long warned that one of the worst things someone at risk for the disease can do is smoke marijuana, as research suggests that it can hasten the onset of the disorder. Skeptics, however, point out that because males are more likely than females both to smoke pot and to develop schizophrenia early, the apparent causal link is merely coincidence.

A new meta-analysis sought to settle the matter. Researchers at the University of New South Wales in Australia reviewed 83 studies and found that pot smokers who developed psychotic disorders did so 2.7 years earlier than nonsmokers. But the use of any illegal drug accelerated the onset of those diseases by two years, so pot's effect was only a bit worse.

The greater risk may be to people with a family history of psychosis. For them, one study found, pot sped up the onset of the disease by three years and worsened symptoms too. The explanation may lie in the brain's endocannabinoid receptors, which respond to the active chemicals in pot and play a role in dopamine regulation, possibly increasing the likelihood of psychotic episodes.

DIET AND IQ

In a British study of children and nutrition, kids who ate a healthy diet (lots of fruits, veggies, rice and pasta) at age 3 had higher IQs at age 8½ than kids who ate meals made up of a lot of fats, sugars and processed foods. The average difference was slight--less than two IQ points--but that can add up. Disturbingly, improving the kids' diets after age 3 could boost their overall health, but it didn't change their intelligence scores.

BREAST CANCER

Less-Extensive Surgery May Be O.K.

Breast-Cancer surgery may never be routine, but there are standard ways to go about it. One rule is that if there is any involvement in the lymph nodes under the arm, all those nodes must go. Now, research funded by the National Cancer Institute calls that protocol into question.

In a study of nearly 900 breast-cancer patients with early-stage disease (known as T1 or T2 tumors), researchers assigned half to a group that had standard surgery, radiation and chemo as well as extensive node removal. The other half had only the sentinel nodes removed--the ones that were tested for the presence of the cancer--but their treatment was otherwise the same.

The five-year survival rates for both groups were similar--about 92%. There was no recurrence of cancer at that point in 83.9% of the women who had the extensive node surgery. For the ones who had the limited surgery, the rate was a slightly lower 82.2%--a statistically insignificant difference.

The findings clearly apply only to women with T1 or T2 tumors--about 20% of breast-cancer patients--but even in those cases, doctors and women must balance the risks and benefits in making a treatment choice. For those who opt for the traditional surgery, risks include infection and later pain and mobility problems in the arm.

FROM THE LABS

Late-Breaking Chocolate Bulletin