Children who face relentless bullying from their peers are at elevated risk of developing psychotic symptoms by the time they reach early adolescence, a British study has revealed.

Previous research has shown that bullying can lead to anxiety, depression and even suicide. But the new study, by researchers at the University of Warwick, is the first to link bullying with psychotic symptoms, which include hallucinations, delusions, and bizarre and paranoid thoughts.

Dieter Wolke, one of the authors of the study, said these early psychotic episodes may act as a trigger for schizophrenia in those who are genetically predisposed to developing the mental disorder.

Essentially, the stress caused by severe and chronic victimization may be enough to push a vulnerable person over the edge, leading to full-blown schizophrenia, Dr. Wolke speculated.

He noted that stress spurs the release of cortisol, a hormone that might alter the developing brain. What's more, being treated badly can have long-lasting effects on the thought processes of an impressionable child.

Further research would be needed to confirm that bullying can be the spark for schizophrenia.

The latest findings, published in Archives of General Psychiatry, are based on an assessment of 6,437 young individuals.

At the ages of 8 and 10, the children were asked if they had been bullied in the past six months. Bullying included threats or acts of physical violence as well as emotional victimization such as being ostracized by a group of other children. Parents and teachers were also quizzed about the extent of bullying.

Then, at the age of 13, the children were assessed for signs of psychotic symptoms.

About 46 per cent of the kids had been victims of bullying to some degree. The children who experienced a great deal of bullying tended to be the ones who were most likely to suffer from psychotic symptoms.

But Dr. Wolke emphasized that the odds of developing such symptoms must be kept in perspective.

"You have an increased risk, but it doesn't mean that most of the children who were bullied developed psychotic symptoms," he said in an interview.

The study showed that up to 18 per cent of those who were severely bullied had some symptoms, he said. By contrast, 4 per cent of those who were not bullied displayed some psychotic-like behaviour, he said.

Nonetheless, bullying is a serious matter with potentially life-altering consequences, he said, adding that schools and parents should adopt strategies to prevent this form of cruel victimization.

MALE BIRTH CONTROL

Is a male version of the birth-control pill finally on the horizon?

Fifty years after the introduction of an oral contraceptive for women, condoms and vasectomies are still the only relatively reliable birth-control options for men.

However, this week, Chinese researchers report they are working on a treatment that can render a man temporarily infertile. It involves monthly injections of a hormone formulation of testosterone undecanoate in tea-seed oil.

Although testosterone is normally associated with virility, too much of it circulating in the blood stream will caused the testes to cut sperm production, according to lead investigator Yi-Qun Gu of the National Research Institute for Family Planning in Beijing.

The treatment was tested on healthy Chinese men aged 20 to 45. According to the findings, published in the Journal of Clinical Endocrinology & Metabolism, only one of every 100 men on the treatment fathered a child during the two-year trial.

A big plus of the treatment is that it's apparently reversible. Once the injections are stopped, sperm production gradually returns to normal.

Some experts expressed doubts about the treatment. And Dr. Gu agrees more work is required before it's considered a family-planning option for men.

"The long-term safety of this hormonal male contraceptive regimen needs to be investigated in future studies, including a focus on cardiovascular, prostate and behavioural safety," he said in an e-mail.

WASH YOUR PAWS

Pet-therapy dogs - used in many hospitals and long-term care facilities to help boost patient morale - could inadvertently become infection spreaders, according to researchers at the University of Guelph.

"It makes sense, really," said Scott Weese, a veterinary internist and microbiologist. "If people have MRSA [an antibiotic-resistant bacterial infection]or anything else on their hands and they pet an animal, there is a potential to transferring that to the animal's coat," he explained.

When the dog moves along, there is a risk that other patients could pick up the infection by petting the animal, he added.

Dr. Weese and colleagues have just published their findings in the Journal of Hospital Infection. Tests found both MRSA and Clostridium difficile (a common cause of infectious diarrhea) on the paws and fur of dogs that had been roaming among patients in an acute-care facility.

But Dr. Weese doesn't think pet-therapy programs should be halted. All that's needed is some very basic infection control measures, he said.

"If they wash their hands or use alcohol-hand sanitizer before they touch the animal, they are not going to transmit it. And if they wash their hands after they pet an animal they are not going to pick up something to infect themselves."

He added: "It's not rocket science, which is why infection control often fails, because it is not all that flashy an issue. But it is important."