Family Anatomy » genetic

Analysis Does Not Support Association Between Genetic Marker, Stress and Risk of Depression

Dr. Brian MacDonald C. Psych. — Fri, 19 Jun 2009 13:30:32 +0000

CHICAGO—Contrary to a previous report, an analysis of 14 previous studies does not find an association between a serotonin transporter gene variation, stressful life events, and an increased risk of major depression, according to an article in the June 17 issue of JAMA. The authors did find that the number of stressful life events is associated with depression.

Despite progress in risk gene identification for several complex diseases, few disorders have proven as resistant to gene identification as psychiatric illnesses. Although these disorders have long been assumed to result from some combination of genetic vulnerability and environmental exposure, direct evidence from a specific example has not been forthcoming. “Few if any of the genes identified in candidate gene association studies of psychiatric disorders have withstood the test of replication and to date, genome-wide association studies of psychiatric disorders have also had limited success,” the authors write. One previous study (Caspi et al) concluded that, in interaction with stressful life events, genetic variation of the serotonin transporter gene (5-HTTLPR) plays a role in predisposition to major depression.(...)
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Post tags: depression, genetic, stress
Note: Posts on Family Anatomy are for education only, and are not intended to replace professional or medical advice. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.

Genetics, environment, and smoking in pregnancy

Dr. Brian MacDonald C. Psych. — Thu, 15 Jan 2009 15:49:53 +0000

A study in the January issue of Developmental Psychology examined the long-term effect of prenatal exposure to tobacco. This project was unique in that the researchers also considered the expression of genes affecting the dopamine (a neurotransmitter) system in the brain.

The researchers asked preschoolers to complete a task that required “executive control;” the executive functions are skills required for goal-directed behaviour, including self-monitoring, inhibiting inappropriate behaviour, and shifting from one task or problem-solving strategy to another. They found that kids with one expression of gene (the genotype; a TaqIA allele was looked at, in case you’re interested) had more trouble than those with another genotype on the executive control task. Kids with the allele who were also exposed to tobacco prenatally had the most trouble of any group on the activity.

The researchers concluded that genes have an effect on behaviour, but their impact is in turn affected by environmental factors as well. It’s not genes OR environment that is important, it’s both. Psychologists have talked about the gene X environment interaction since before I went to school, with some suggesting a “diathesis-stress” model for a number of psychological conditions. That is, genetics might predispose someone to be at a higher risk for certain kinds of difficulties, but the environmental factors have an impact on the eventual outcomes.

You can read more here.

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Note: Posts on Family Anatomy are for information only. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.

© Dr. Brian MacDonald C. Psych. for Family Anatomy, 2009. | Permalink | No comment | Add to del.icio.us
Post tags: environment, executive control, executive functions, genes, genetic, pregnancy, smoking
Note: Posts on Family Anatomy are for education only, and are not intended to replace professional or medical advice. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.

First gene for child brain tumour identified

richardbolduc — Sun, 09 Nov 2008 13:03:48 +0000

Brain tumours are the second most common type of childhood cancer. Pilocytic astrocytomas affect around 145 children each year in the UK. Lead author Professor Peter Collins, based at the University of Cambridge, said: “This is the first time a specific genetic link has been made to the majority of pilocytic astrocytomas. What has occured is that scientists have found the first genetic link to a common childhood brain tumour. This was¬†revealed through¬†research published in the Journal of Cancer Research.”

The Cambridge researchers¬†have pinpointed a rearrangement of DNA that causes¬†a majority¬†of all cases of pilocytic astrocytoma – the most common brain tumour in five to 19 year-olds. It was revealed that very little is known about the causes and genetics of childhood brain tumours. However, this¬†discovery could help in providing better¬†leads for¬†more acurate treatments and¬†diagnoses of this disease with greater acuracy.

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Post tags: brain tumour, cancer, DNA, genetic, tumor
Note: Posts on Family Anatomy are for education only, and are not intended to replace professional or medical advice. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.

Will he still love you tomorrow?

Dr. Brian MacDonald C. Psych. — Tue, 02 Sep 2008 23:59:05 +0000

A new study was published in the Proceedings of the National Academy of Sciences suggesting a genetic link to monogamy and marital satisfaction. Researchers found that men with 2 copies of the allele responsible for the distribution of vasopressin receptors in the brain were twice as likely to report marital dysfunction and to have considered divorce than those with one or no copies of the allele. They noted that human behaviour is determined by a number of factors besides genetic expression.

You can read more here.

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Post tags: couples, dysfunction, genetic, marriage, monogamy, Relationships, vasopressin
Note: Posts on Family Anatomy are for education only, and are not intended to replace professional or medical advice. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.

Yoga and meditation at the cellular level

Dr. Brian MacDonald C. Psych. — Thu, 03 Jul 2008 00:50:50 +0000

PLoS ONE published an article today comparing long-term meditation and yoga practitioners to a group of controls and a group who had taken an 8-week relaxation training course. The researchers found differences in the expression of over 2200 genes, some of which affected cellular metabolism and response to oxidative stress in the long- and short-term “relaxation group”. The study concluded that relaxation training can protect cells against damage related to chronic stress.

You can read more here.

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© Dr. Brian MacDonald C. Psych. for Family Anatomy, 2008. | Permalink | 2 comments | Add to del.icio.us
Post tags: genes, genetic, meditation, relaxation, stress, yoga
Note: Posts on Family Anatomy are for education only, and are not intended to replace professional or medical advice. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.

Genetic links to autism

Dr. Brian MacDonald C. Psych. — Wed, 11 Jun 2008 01:24:30 +0000

A study published in the May 2008 issue of Biological Psychiatry found a strong connection between genes responsible for maternal and affiliative behaviours and autism spectrum disorders. The authors examined ASD symptoms in children with the diagnosis, and found links with genetic test results. They admit that further testing is needed to confirm the association, however.

You can read more here.

© Dr. Brian MacDonald C. Psych. for Family Anatomy, 2008. | Permalink | No comment | Add to del.icio.us
Post tags: autism, Development, genetic, infants
Note: Posts on Family Anatomy are for education only, and are not intended to replace professional or medical advice. If you need to talk to someone about family or mental health issues, you can get a referral from your family doctor.