Research update: CrossCurrents Summer 2004

CrossCurrents

Childhood sleep problems may signal risk for adult drug use

Children who have trouble sleeping may be at greater risk for drinking, smoking and using other drugs as teenagers, according to researchers at the University of Michigan. Researchers interviewed the mothers of 257 boys between the ages of three and five about their sleep habits. Follow-up interviews were conducted with families at three-year intervals until the children were between the ages of 12 and 14. The children were given a confidential written questionnaire, asking about alcohol, cigarettes and other drug use. The study found that one-third of the boys had trouble sleeping or were overtired as children. They were more than twice as likely as other boys to experiment with alcohol, cannabis and any illicit drugs as teenagers. The link between sleep problems and substance use held even after depression, anxiety, attention problems and parental alcohol use were taken into account. The researchers suggest that some as-yet unknown brain mechanism may be involved in both sleeplessness and a tendency to addiction. The authors caution, however, that poor sleep does not necessarily cause later addiction problems.

Alcoholism: Clinical and Experimental Research, April 2004, v. 28: 578-587. Maria M. Wong et al., Department of Psychiatry, University of Michigan, Ann Arbor, Michigan.

Drinking interrelated with nicotine addiction

People who drink are more likely to smoke because alcohol enhances the pleasurable effects of nicotine, say researchers at Duke University Medical Center in Durham, North Carolina. The findings provide a physiological explanation for the observation that people smoke more in bars. Researchers recruited 48 regular smokers who drank at least four alcoholic beverages per week. Participants were given either an alcoholic or placebo beverage, and either regular or nicotine-free cigarettes. According to participant ratings, ethanol enhanced many of the rewarding effects of nicotine compared to placebos. Smoking nicotine-free cigarettes did not elicit the same positive response from those receiving alcohol, indicating that nicotine itself, rather than other aspects of smoking, was the critical ingredient underlying the interaction. The researchers also compared participants' responses to nicotine after they took mecamylamine, a nicotine agonist. Participants on mecamylamine smoked more initially to off-set the drug's action, but reported reduced satisfaction from smoking. This result further supports the idea that ethanol enhances nicotine's effects. The research supports statistics that people with alcohol dependency smoke more than others and that smokers are 10 times more likely than non-smokers to have alcohol dependency. The researchers say the findings may explain why people who have quit smoking often relapse when they drink alcohol, and may lead to new smoking cessation methods that take the drugs' interaction into account.

Nicotine & Tobacco Research, February 2004, v. 6: 133-144. Jed E. Rose et al., VA Medical Center and Department of Psychiatry, Duke University Medical Center, Durham, North Carolina.

Scientists identify gene linked to autism

Two variants of a single gene have been found that may at least double a child's risk of developing autism, according to researchers at the Mount Sinai School of Medicine in New York. The variation was found with two single nucleitide polymorphisms within the SLC25A12 gene. The variants are fairly common and cannot bring on the disease by themselves, say the researchers, who indicate that between five and 10 genes may need to work together to produce autism. The study looked at 411 families, analyzing DNA from more than 2,000 people. Of those, 720 had autism. The study found that the two gene variants had been inherited by family members with autism more often than could be expected by chance, which implicates the variants in the disease. Previous studies have identified variants in other genes that may contribute to the disease, but none has been proven to do so. Autism, which normally appears by age three, and usually in boys, interferes with a child's ability to communicate and interact with others. Since the gene is involved in providing energy to brain cells, the researchers speculate that variant versions may hamper the operation of those cells.

American Journal of Psychiatry, April 2004, v. 161: 662-669. Nicolas Ramoz et al., Mount Sinai School of Medicine, New York.

Primary care reduces suicidal ideation in older adults

A primary care intervention can reduce suicidal ideation in older adults with depression, according to research out of Cornell University in White Plains, New York. Between 1999 and 2001, the Prevention of Suicide in Primary Care Elderly: Collaborative Trial took place at 20 primary care practices in New York City, Philadelphia and Pittsburgh. After a two-stage, age-stratified depression screening of randomly sampled participants, aged 60 to 74-75 years and older, the researchers enrolled participants who screened positive and a random sample of those who screened negative. The study involved 598 individuals diagnosed with depression. The intervention included a trial of the antidepressant citralopram and treatment management by depression care managers. Degree and speed of symptom reduction were better in the intervention group than the control group. At four months, participants in the intervention group reported a decrease in suicidal ideation from 29 per cent to 17 per cent, while the rate among those who did not receive the intervention fell from 20 per cent to 17 per cent. At eight months, 70 per cent of the intervention group no longer reported suicidal ideation, compared with 44 per cent of the control group. The authors conclude that the intervention may be an effective preventive strategy to reduce risk factors for suicide in later life.

Journal of the American Medical Association, March 3, 2004, v. 291: 1081-1091. Martha L. Bruce et al., Department of Psychiatry, Weill Medical College of Cornell University, White Plains, New York.

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