Passive smoking linked to behavioural disorders; ADHD stress shortens lives

Passive smoking has well-known effects on health, and a new study has found it could also cause behavioural disorders in children. Researchers from Inserm and Pierre and Marie Curie University, in collaboration with the university hospitals of six French cities, analysed data on pre- and postnatal exposure to tobacco in the homes of 5,200 primary-school children. Behavioural disorders were assessed via the Strengths and Difficulties Questionnaire used to assess the behavioural and psychosocial functioning of the children, which was also completed by the parents. The researchers found an association between tobacco exposure and the risk of emotional and conduct disorders in children. The association exists in cases of prenatal or postnatal exposure alone, but is stronger with exposure during both periods. During pregnancy, nicotine in tobacco smoke stimulates acetylcholine receptors, and causes structural changes in the brain. In the first months of life, exposure to tobacco smoke generates a protein imbalance that leads to altered neuronal growth, the researchers explain.

Hyperactive children and their mothers are more likely to have chromosome changes associated with an increased risk for chronic diseases and conditions such as diabetes, obesity and cancer, according to a new study by Brazilian scientists. The study assessed the length of telomeres - the caps at the ends of chromosomes that act as protection against the loss of protein-coding DNA during cell division - in 61 children, aged between six and 16, who were diagnosed with attention deficit hyperactivity disorder (ADHD) and in their parents. Telomeres shorten naturally with ageing, but the process is accelerated by psychological and biological stress. The shorter the telomeres, the shorter one's life expectancy. The children in the study were found to have shorter telomeres than those that would be expected for their ages. Although mothers' telomeres were also shorter, they did not find any alteration in the fathers' telomere length. The researchers believe the phenomenon is due to the stress that ADHD symptoms generate for the children and their mothers.