Are there any hereditary psychiatric conditions?
Are there any mental or psychiatric conditions that are known to be hereditary other than OCD?
Yes. Schizophrenia - we know that the risk rises very much so if you have a first degree or near-relative with the condition. Also bipolar disorder. They're two very common conditions. They affect between one and two percent of the population.
Scientists are now beginning to apply the power of molecular biology to try to find out what the genes are that are linked to these conditions. They're using something called single nucleotide polymorphism analysis or SNP analysis. What this involves is a big group of people who have the disorder, a group of people who don't have the disorder and then you look across their DNA for these little molecular markers called SNPs to see if they crop up more often in certain places of the genome in people who have a condition than people who don't. That gives you a kind of flag sign or a way-marker to say this bit of the DNA might be important in this condition. Then you can focus your attention much more closely in that area. The same analysis has proved that there are various other genes that, in addition to the ones we knew about, are linked to things like genetics for breast cancer and diabetes in the last twelve months. I think we'll probably see quite a lot of fruit being borne out by that procedure quite soon.