Visual impairment indirectly linked to suicide

NEW YORK (Reuters Health) — Visual impairment alone does not significantly increase the risk of suicide, but it does seem to do so when it is associated with poor health, according to a report in the Archives of Ophthalmology.

The findings suggest that better treatments for the underlying conditions that cause visual impairment, along with factors linked with poor self-ratings of health and health conditions may reduce the risk of suicide, Dr. Byron L. Lam, from the Bascom Palmer Eye Institute in Miami, and colleagues conclude.

The findings stem from an analysis of data for 137,479 adults who participated in surveys conducted by the National Center for Health Statistics between 1986 and 1996.

Data from these surveys were then linked to mortality data from the National Death Index.

During an average follow-up period of 11.0 years, 200 suicide deaths were recorded, the report indicates.

After accounting for the possible influence of various demographic factors, the number of health conditions unrelated to vision, self-rated health, visual impairment was linked with a 50 percent increased risk of death by suicide, although the association was not statistically significant, meaning the association could possibly have been the result of chance.

By contrast, the association of suicide with poorer self-rated health, n increased number of health conditions unrelated to the eye, and visual impairment did have an indirect, significant relationship with increased suicide risk.

These results suggest that older adults, those with health conditions that don't involve the eye, and those with self-rated poor health and visual impairment are at increased risk of suicide.

Eye care professionals should be aware of the potential increased risk of suicide for patients with visual impairment, especially those in poor health, and provide appropriate referrals for these patients," the authors emphasise.

Baby's smile gives mom a natural high

NEW YORK (Reuters Health) — A baby's smile does more than warm a mother's heart — it also lights up the reward centres of her brain, according to the results of a brain imaging study.

The finding, investigators say, could go a long way in helping researchers dissect the unique bond between mother and infant and how it sometimes goes wrong.

"The relationship between mothers and infants is critical for child development," Dr. Lane Strathearn, of the Human Neuroimaging Laboratory at Baylor College of Medicine, Houston noted in a statement.

"For whatever reason, in some cases, that relationship doesn't develop normally. Neglect and abuse can result, with devastating effects on a child's development," Strathearn explained.

Strathearn and colleagues used magnetic resonance imaging (MRI) to scan the brains of 28 first-time mothers of five to ten-month-old infants while they looked at photos of their own babies and other infants.

In some of the photos babies were smiling or happy. In others, the infants were sad and in some they had neutral expressions.

The investigators found that when the mothers saw their own infants' faces, key areas of the brain associated with reward lit up during the scans, suggesting increased blood flow to that area.

The areas stimulated by the sight of their own babies were those involved in thinking, movement, behaviour and emotion.

"These are areas that have been activated in other experiments associated with drug addiction," said Strathearn.

"It may be that seeing your own baby's smiling face is like a 'natural high,'" the investigator added.

Botox shots may help ward off migraines

NEW YORK (Reuters Health) — Injections of botulinum toxin — better known as Botox — may help prevent migraines in people who suffer frequent migraine attacks that are poorly controlled with oral prevention therapies, research hints.

In a study lasting six months, Drs. Roger Cady and Curtis Schreiber of the Headache Care Center in Springfield, Missouri evaluated the efficacy and safety of a single series of Botox injections, versus placebo shots, for preventing migraine.

They report in the journal Headache that Botox had "beneficial, albeit limited, effects on measures of migraine frequency and was not effective in lowering headache pain severity."

However, Botox-treated patients did have fewer headache "episodes" and fewer headache days than placebo-treated patients. Moreover, Botox had a "measurable" positive impact on quality-of-life.

For example, improvement in the Headache Impact Test — a six-item survey of pain, role functioning, social functioning, fatigue, cognition, and emotional distress — was significantly greater for Botox-treated patients than for placebo-treated patients.

Cady and Schreiber think Botox "may be a useful treatment option" for headache patients who aren't doing well on other migraine preventive agents.

New genetic mutation tied to Alzheimer's

NEW YORK (Reuters Health) — Scientists have found evidence that a mutation in a gene called CALHM1 that results in abnormal calcium signalling influences the risk of Alzheimer's disease, a devastating neurodegenerative disease that affects early 18 million people in the world.

"CALHM1 is an attractive new drug target," Dr. Fabien Campagne from Weill Medical College of Cornell University, New York, told Reuters Health. "The design of drugs that activate CALHM1 could have a beneficial effect in patients who do not have the polymorphism (mutation), as well as in patients who carry the polymorphism."

The CALHM1 mutation is associated with the late-onset form of Alzheimer's disease. This form of the disease affects people age 65 and older and represents about 90 percent of Alzheimer's cases. The rarer early-onset inherited form of the disease affects people from about age 30 to 65.

According to the scientists, the CALHM1 mutation seems to disrupt a previously uncharacterised brain calcium channel and fuels the subsequent accumulation of amyloid beta protein — an important component of the senile plaques that clog up the brains of patients with Alzheimer's disease.