Children whose mothers are genetically predisposed to have impaired production of serotonin appear more likely to develop attention-deficit hyperactivity disorder (ADHD) later in life, according to a report in the October issue of Archives of General Psychiatry, one of the JAMA/Archives journals.
Would tryptophan or serotonin supplementation cut the risk of developing ADHD as a child?
Anne Halmøy, M.D., of University of Bergen, Norway, and colleagues studied 459 adult outpatients with ADHD, 97 of their family members and 187 control individuals recruited from across Norway. Participants provided blood samples for gene sequencing along with information about psychiatric diagnoses and symptoms.
By sequencing 646 individuals, the researchers identified nine different mutations, of which eight were significantly associated with impaired function of the enzymes. Family analysis of 38 individuals who carried these mutations and 41 of their offspring revealed that children of mothers who had one of the mutations—and, therefore, had impaired serotonin production—had a 1.5- to 2.5-time higher risk of ADHD than control individuals or offspring of fathers with the mutations.
I think we are getting close to the age when most genetic factors that contribute to cognitive performance become known. This makes the advantages from in vitro fertilization combined with genetic testing. The advantage from starting pregnancies will become so compelling that a rising fraction of all pregnancies will be started with IVF.
In children inattention leads to depression but hyperactivity ups the risk of suicide. Makes sense in a way: hyperactive people have the energy to kill themselves.
The authors also categorized ADHD into three subtypes and found that each one (inattentiveness, hyperactivity and/or a combination of the two) predicted somewhat different outcomes. While children who have a combination of inattention and hyperactivity predicted both depression and attempted suicide, children who experience only inattentiveness predicted only depression. Children showing only hyperactivity predicted suicide attempts but not depression.
|Share |||Randall Parker, 2010 October 04 11:12 PM Brain Genetics|