By: Hema Zbogar
People who consume moderate amounts of alcohol have smaller brains than non-drinkers, according to researchers at Johns Hopkins University. Researchers used magnetic resonance imaging to examine the brains of 1,909 individuals in their mid-50s. Participants were assigned into five groups according to their drinking habits: non-drinkers, former drinkers, occasional drinkers (less than one drink per week), low drinkers (one to six drinks per week) and moderate drinkers (seven or more drinks per week). Participants underwent a cerebral MRI in 1993–1995. The researchers found that as drinking increased, brain atrophy was more common, although the amount of reduced brain size was very small. Previous studies have shown that moderate drinking may be beneficial for the heart, but the current study found it did not protect against stroke. The researchers speculate that moderate drinking may have a separate toxic effect on brain cells, which would explain the brain atrophy.
Stroke, January 2004; v. 35: 16–21. Jingzhong Ding et al., Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins Univer-sity, Baltimore, Maryland.
Maternal smoking during pregnancy may be associated with attention-deficit hyperactivity disorder (ADHD) symptoms in offspring, according to researchers at the University of Wales College of Medicine. Families of 1,452 twin pairs, age 5–16, were sent a package of questionnaires, asking the mother about children’s ADHD symptoms, maternal smoking during pregnancy, conduct disorder symptoms and family adversity. Teachers were also asked to complete an ADHD rating scale on each twin. Although genetic factors accounted for most of the variance in ADHD, the current study is the first to find that maternal smoking during pregnancy was associated with ADHD symptoms, even after the results were adjusted for social adversity, birth weight and antisocial symptom scores.
American Journal of Psychiatry, November 2003, v. 160: 1985-1989. Anita Thapar et al, Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, Wales.
A study of intoxication in laboratory roundworms has found a gene that may explain why some people are most resistant to alcohol’s effects. Researchers at the University of California, San Francisco, screened thousands of the fast-breeding lab worms known as C. elegans in search of genes that could explain why some worms seem immune to the effects of alcohol. Results showed that strong resistance to alcohol intoxication could be explained entirely by mutation of a single gene, called slo-1. This gene controls a chemical message circuit in the brain – the BK channel, which is also found in humans. Researchers found that alcohol acts on this channel in nerve cells to cause neural depression (slowing of nerve function) and intoxication. When the channel was exposed to alcohol, worms with the gene moved in a way that indicated they were intoxicated. In worms that did not have the gene, exposure to alcohol had no effect. The researchers suggest that this gene, or other genes that interact with it, could account for some of the variability in the way humans respond to alcohol. While previous studies have identified a number of genes that can influence how alcohol affects behaviour, this is the first finding that a single gene and the protein it controls are responsible for intoxication. The researchers suggest that their findings might lead to the development of a drug that could change the effect of alcohol on the BK channel. They add that human studies are needed to determine whether this channel or the pathways involving this channel are defective in people with alcohol dependency.
Cell, December 12, 2003, v. 15: 655–666. Andrew G. Davies et al, Ernest Gallo Clinic and Research Center, University of California, San Francisco, Emeryville, California.
Asthma may be associated with a range of psychiatric disorders, according to researchers at Columbia University in New York. The researchers studied a sample of adults, age 18–65, in Germany. They based their diagnoses of current (past four weeks) and lifetime asthma on physician diagnosis and used the Composite International Diagnostic Interview to assess current and lifetime psychiatric disorders. The study found that individuals with current severe asthma were significantly more likely to have an anxiety disorder, phobia, panic disorder or panic attacks. A diagnosis of lifetime severe asthma was associated with an increased likelihood of anxiety disorder, panic disorder, panic attacks, social phobia, specific phobia, generalized anxiety disorder and bipolar disorder. Current and lifetime non-severe asthma were also linked to increased likelihood of any affective disorder and any severe mental disorder. The authors suggest that longitudinal studies be conducted to examine the sequence of onset and the role of genetic and environmental factors in the association between asthma and affective and anxiety disorders.
Archives of General Psychiatry, November 2003, v. 60:1125–1130. Renee D. Goodwin, Frank Jacobi and Wolfgang Thefeld, Institute of Clinical Psychology and Psychotherapy, Technical Univer-sity of Dresden, Dresden, Germany.
Susceptibility to psychological distress may be linked with the risk of Alzheimer’s disease (AD). Researchers at Rush-Presbyterian-St. Luke’s Medical Center in Chicago, Illinois, hypothesized that propensity to experience psychological distress is related to risk of AD because chronic stressful experience is linked to structural changes in the hippocampus and with impaired learning and memory. Researchers analyzed data from the Religious Orders Study, which included 797 individuals, average age 75, who were free of dementia at baseline. Participants underwent complete neurologic examinations and completed a measure of the tendency to experience psychological distress that indicated susceptibility to negative emotional states across the life span. At annual follow-ups, with a mean of five years, participants underwent a battery of 19 cognitive tests. During this time, 140 individuals were diagnosed with AD. Researchers found that each one-point increase in distress proneness was associated with a six per cent increased risk of AD and a seven per cent decline in global cognition. Those high in distress proneness had twice the risk of developing AD than those low in distress proneness. Distress proneness was related to decline in episodic memory, which the researchers note is primarily mediated by hippocampal formation, but not in other cognitive systems. The authors suggest that chronic psychological distress may be a risk factor for AD and that this association may reflect a neurobiological mechanism other than the pathologic hallmarks of AD.
Neurology, December 9, 2003, v. 61:1479–1485. R.S. Wilson et al, Rush Alzheimer’s Disease Center, Rush-Presbyterian-St. Luke’s Medical Center, Chicago, Illinois.
Road rage is related to psychiatric distress, according to research at the Centre for Addiction and Mental Health (CAMH) in Toronto. Researchers studied data on road rage involvement, demographic characteristics and mental health among 2,610 Ontario adults, age 18 and over. Data were drawn from the CAMH Monitor, a repeated cross-sectional telephone survey of Ontario adults. The General Health Questionnaire was used to indicate current psychiatric distress. The study found five groups of people affected by road rage: those with little or no involvement, verbal-threat offenders, verbal victims, verbal victim-offenders and hard-core road rage perpetrators (individuals noted for frequent involvement in serious aggressive and violent conduct). Only the hard-core road rage perpetrators had significantly higher scores on the GHQ, indicating greater psychiatric distress among this group. The researchers recommend that further research be conducted to determine whether psychiatric problems lead to road rage, whether road rage leads to psychiatric problems or whether both processes are occurring.
Canadian Journal of Psychiatry, November 2003, v. 48: 681-688. Reginald G. Smart et al, Centre for Addiction and Mental Health, Toronto, Ontario
About one-half of juvenile detainees in the United States have at least two mental health disorders and more than one in 10 have both a psychiatric disorder and a substance use problem. The findings are based on screenings of 1,829 residents, age 10–18, at a detention centre in Cook County, Illinois. All detainees were awaiting trial or serving out a sentence of less than 30 days. Criteria for two or more psychiatric disorders were met by 56 per cent of females and 46 per cent of males. Fourteen per cent of females and 11 per cent of males had both a major psychiatric disorder and a substance use problem. Previous research has shown that young people in detention centres have a high rate of mental health problems, but the researchers note that having more than one psychiatric disorder raises special concerns, particularly since most treatment programs are set up to handle only people with one disorder. The researchers recommend that officials in the justice system team up with mental health experts to help with diagnoses and finding appropriate treatment upon release.
Archives of General Psychiatry, November 2003, v. 60: 1097-1108. Karen M. Abram et al, Department of Psychiatry and Behavioral Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.