Study: Cognitive Training Shows Staying Power

   (NIH) - 1/16/2014 - Training to improve cognitive abilities in older people lasted to some degree 10 years after the training program was completed, according to results of a randomized clinical trial supported by the National Institutes of Health.
   The findings showed training gains for aspects of cognition involved in the ability to think and learn, but researchers said memory training did not have an effect after 10 years.
   The report, from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, appears in the January 2014 issue of the Journal of the American Geriatrics Society. The project was funded by the National Institute on Aging (NIA) and the National Institute of Nursing Research (NINR), components of the NIH.
   “Previous data from this clinical trial demonstrated that the effects of the training lasted for five years,” said NIA Director Richard J. Hodes, M.D. “Now, these longer term results indicate that particular types of cognitive training can provide a lasting benefit a decade later. They suggest that we should continue to pursue cognitive training as an intervention that might help maintain the mental abilities of older people so that they may remain independent and in the community.”
   “ACTIVE is an important example of intervention research aimed at enabling older people to maintain their cognitive abilities as they age,” NINR Director Patricia Grady said. “The average age of the individuals who have been followed over the last 10 years is now 82. Given our nation’s aging population, this type of research is an increasingly high priority.”
   The original 2,832 volunteers for the ACTIVE study were divided into three training groups — memory, reasoning and speed-of-processing — and a control group. The training groups participated in 10 60- to 70-minute sessions over five to six weeks, with some randomly selected for later booster sessions. The study measured effects for each specific cognitive ability trained immediately following the sessions and at one, two, three, five and 10 years after the training.
   The investigators were also interested in whether the training had an effect on the participants’ abilities to undertake some everyday and complex tasks of daily living. They assessed these using standardized measures of time and efficiency in performing daily activities, as well as asking the participants to report on their ability to carry out everyday tasks ranging from preparing meals, housework, finances, health care, using the telephone, shopping, travel and needing assistance in dressing, personal hygiene and bathing.
   At the end of the trial, all groups showed declines from their baseline tests in memory, reasoning and speed of processing. However, the participants who had training in reasoning and speed of processing experienced less decline than those in the memory and control groups. Results of the cognitive tests after 10 years show that 73.6 percent of reasoning-trained participants were still performing reasoning tasks above their pre-trial baseline level compared to 61.7 percent of control participants, who received no training and were only benefiting from practice on the test. This same pattern was seen in speed training: 70.7 percent of speed-trained participants were performing at or above their baseline level compared to 48.8 percent of controls. There was no difference in memory performance between the memory group and the control group after 10 years.
   Participants in all training groups said they had less difficulty performing the everyday tasks compared with those in the control group. However, standard tests of function conducted by the researchers showed no difference in functional abilities among the groups.
   “The speed-of-processing results are very encouraging,” said Jonathan W. King, Ph.D., program director for cognitive aging in the Division of Behavioral and Social Research at NIA and co-author. “The self-reported improvements in daily function are interesting, but we do not yet know whether they would truly allow older people to live independently longer; if they did, even a small effect would be important, not only for the older adults, but also for family members and others providing care.”
   The ACTIVE study followed healthy, community-dwelling older adults from six cities — Baltimore; Birmingham, Ala.; Boston; Detroit; State College, Pa.; and Indianapolis. The participants averaged 74 years of age at the beginning of the study and 14 years of education, 76 percent were female, 74 percent were white and 26 percent were African-American. The 10-year follow-up was conducted with 44 percent of the original sample between April 1998 and October 2010.
   The ACTIVE study was conducted by the following investigators:

• George W. Rebok, Ph.D., Johns Hopkins University, Baltimore
• Karlene Ball, Ph.D., University of Alabama at Birmingham
• Michael Marsiske, Ph.D., University of Florida, Gainesville
• John N. Morris, Ph.D., and Richard N. Jones, Sc.D., Hebrew Senior Life, Boston
• Sharon L. Tennstedt, Ph.D., New England Research Institutes, Watertown, Mass.
• Frederick W. Unverzagt, Ph.D., Indiana University School of Medicine, Indianapolis
• Sherry L. Willis, Ph.D., University of Washington, Seattle

   The National Institute of Nursing Research (NINR) supports basic and clinical research that develops the knowledge to build the scientific foundation for clinical practice, prevent disease and disability, manage and eliminate symptoms caused by illness, and enhance end-of-life and palliative care. See: http://www.ninr.nih.gov. For more information on research, aging, and health, go to http://www.nia.nih.gov.

Genetic overlap seen between mental disorders

   (NIH) - 8/23/2013 - The largest genome-wide study of its kind has determined how much five major mental illnesses are traceable to the same common inherited genetic variations. Researchers funded in part by the National Institutes of Health found that the overlap was highest between schizophrenia and bipolar disorder; moderate for bipolar disorder and depression and for ADHD and depression; and low between schizophrenia and autism. Overall, common genetic variation accounted for 17-28 percent of risk for the illnesses.
   “Since our study only looked at common gene variants, the total genetic overlap between the disorders is likely higher,” Naomi Wray said. Wray is with the University of Queensland, Brisbane, Australia, and co-led the multi-site study by the Cross Disorders Group of the Psychiatric Genomics Consortium (PGC), which is supported by the NIH’s National Institute of Mental Health (NIMH).

   “Shared variants with smaller effects, rare variants, mutations, duplications, deletions, and gene-environment interactions also contribute to these illnesses,” Wray said.

   Wray, Kenneth Kendler of Virginia Commonwealth University, Richmond, Jordan Smoller, M.D., of Massachusetts General Hospital, Boston, and other members of the PGC group reported on their findings on August 11 in the journal Nature Genetics.
   “Such evidence quantifying shared genetic risk factors among traditional psychiatric diagnoses will help us move toward classification that will be more faithful to nature,” Bruce Cuthbert said. Cuthbert is director of the NIMH Division of Adult Translational Research and Treatment Development and coordinator of the Institute’s Research Domain Criteria (RDoC) project, which is developing a mental disorders classification system for research based more on underlying causes.
   Earlier this year, PGC researchers — more than 300 scientists at 80 research centers in 20 countries — reported the first evidence of overlap between all five disorders. People with the disorders were more likely to have suspect variation at the same four chromosomal sites. But the extent of the overlap remained unclear. In the new study, they used the same genome-wide information and the largest data sets currently available to estimate the risk for the illnesses attributable to any of hundreds of thousands of sites of common variability in the genetic code across chromosomes. They looked for similarities in such genetic variation among several thousand people with each illness and compared them to controls — calculating the extent to which pairs of disorders are linked to the same genetic variants.
   The overlap in heritability attributable to common genetic variation was about 15 percent between schizophrenia and bipolar disorder, about 10 percent between bipolar disorder and depression, about 9 percent between schizophrenia and depression, and about 3 percent between schizophrenia and autism.
   The new found molecular genetic evidence linking schizophrenia and depression, if replicated, could have important implications for diagnostics and research, say the researchers. They expected to see more overlap between ADHD and autism, but the modest schizophrenia-autism connection is consistent with other emerging evidence.
   The study results also attach numbers to molecular evidence documenting the importance of heritability traceable to common genetic variation in causing these five major mental illnesses. Yet this still leaves much of the likely inherited genetic contribution to the disorders unexplained — not to mention non-inherited genetic factors. For example, common genetic variation accounted for 23 percent of schizophrenia, but evidence from twin and family studies estimate its total heritability at 81 percent. Similarly, the gaps are 25 percent vs. 75 percent for bipolar disorder, 28 percent vs. 75 percent for ADHD, 14 percent vs. 80 percent for autism, and 21 percent vs. 37 percent for depression.
   Among other types of genetic inheritance known to affect risk and not detected in this study are contributions from rare variants not associated with common sites of genetic variation. However, the researchers say that their results show clearly that more illness-linked common variants with small effects will be discovered with the greater statistical power that comes with larger sample sizes.
   “It is encouraging that the estimates of genetic contributions to mental disorders trace those from more traditional family and twin studies. The study points to a future of active gene discovery for mental disorders," NIMH Genomics Research Branch Chief Thomas Lehner said.
   Source: National Institutes of Health