The average suicidal rate is 3.6 per 100,000 people where Bahrain remains to be the highest country with 9.8 per 100,000 people and the least remains to be Hong Kong with 1.2 per 100,000 people. US also fit a good number of such cases where the suicidal rate in US is 4.5 per 100,000 people. What make people to commit suicides? There are numerous studies happening in this field. One such effort by John Hopkins team has come up with few evidences which suggest that there exist genetic changes in the suicidal brains. Studies suggest that changes occurring in the brain of a suicide victim differ strikingly from those in other brains. And most importantly these changes are not all of a sudden, they happen over a course in a lifetime.
The study in Canada suggests that the individuals committing suicide have an abnormal distribution of receptors for GABA. GABA is one of the most abundant neurotransmitters in the brain which inhibits neuron activity. A study by Poulter suggests that the Frontopolar Cortex is the part of brain involved in higher order thinking such as Decision making. GABA is under represented in the suicidal brains which might be one of the factors observed only in suicidal brains.
Fascinatingly, this change in GABA is not mutation or any genetic change; it is rather Epigenetic, meaning environmental influence on genes and the gene products. Environmental influences during pregnancy might also affect the baby which may increase the risk of eventual suicide. Similarly premature babies have 4 times higher risk of eventual suicide.