Testing for Psychotic Disorders

[wren1187]

I've heard that if you have schizophrenia in your biological family there is a small percentage that you are vulnerable. This percentage varies depending on how closely related you are. If one person in a set of identical twins suffers from schizophrenia then his/her twin is 50% likely to get it because he/she has a similar... something going on in the brain. This person has it, but schizophrenia may never show itself unless triggered by drugs or serious trauma.

Now to the question. Does anyone know if it is possible to have an MRI or some kind of brain scan to see how genetically vulnerable one is to develop schizophrenia?

 

[David Baxter PhD]

There is a lot of very promising research currently underway into the genetics and neurochemistry of schizophrenia and other mental disorders.

However, I don't know of any foolproof way to estimate specific individual risk at this time.

 

[Daniel E.]

Does anyone know if it is possible to have an MRI or some kind of brain scan to see how genetically vulnerable one is to develop schizophrenia?

Though genetic testing for schizophrenia isn't a viable option for the immediate future, even do-it-yourself genetic counseling can be helpful. If one's knowledge of family history is very limited, then the chart below may be most helpful:

Lifetime risk based on relationship to person with schizophrenia:

General population: 1%

First-degree relative

Identical twin: 40%–48%
Fraternal twin: 10%–17%
Sibling: 9%
Parent: 6%–13%
Offspring: 13%

Second-degree relative

Aunt/uncle: 2%
Niece/nephew: 4%
Grandchild: 5%

Third-degree relative

First cousin: 2%

Source: Hill & Sahar. "Genetic counselling for psychiatric disorders." The Medical Journal of Australia, 2006 Adapted from Finn CT, Smoller JW. "Genetic counseling in psychiatry." Harv Rev Psychiatry 2006; 14: 109-121

BTW, the National Society of Genetic Counselors website only lists 10 genetic counselors who specialize in psychiatric disorders.

 

[Daniel E.]

Also:

The main known risk factors in development of schizophrenia are genetic causes, pregnancy and delivery complications, slow neuromotor development, and deviant cognitive and academic performance. However, their effect size and predictive power are small. No powerful risk factor, premorbid sign or risk indicator has been identified that is useful for the prediction of schizophrenia in the general population. Predictors of schizophrenia (2005)

 

[Into The Light]

daniel can you provide a similar summary for depression and bipolar disorder as well? i'm not sure where to look on the website.

 

[NightOwl]

I don't know of any testing that I can say, but I know someone that was rapidly moving towards promotion in the medical field and was then affected by Schizophrenia after the birth of her second child. She had an Aunt that also suffered from Schizophrenia, not too sure about the rest of the family.

NightOwl

 

[Daniel E.]

daniel can you provide a similar summary for depression and bipolar disorder as well? i'm not sure where to look on the website.

http://www.nchpeg.org/cdrom/empiric.html
http://www.nchpeg.org/cdrom/ageonset.htm

 

[Daniel E.]

BTW, at NCHPEG.org they also provide an educational "online CD-ROM" called Genetics and Major Psychiatric Disorders: A Program for Genetic Counselors (Shockwave animation). However, the online CD-ROM doesn't seem to load even after one installs Shockwave and an extra file (QT3Asset.x32). I'm going to send them an e-mail on Monday. (My guess is that their "server isn't aware of the mime type for the cct" files they use (tech note).)

 

[Into The Light]

thanks for the links daniel