Many studies have been done trying to narrow down the racial probabilities of mental disease, including depression. Depression seems to effects just over 6.5% of Americans every year and that number being very similar for the percentage of Caucasians effected by the disease. Depression also tends to overlap with many other mental health issues including schizophrenia. The percentage of Caucasians who tend to have depression issues as well as be schizophrenic, are higher in Caucasians than in other races. The results of this may indeed be genetic. However, there is more evidence that points to perhaps the numbers being skewed due to track-ability of information.
Below is a chart that shows data of a study done on 206 vets and the use of antidepressants v psychotherapy treatments on their depression.
*Kasckow,Differences in Treatment Attitudes Between Depressed African-American and Caucasian Veterans in Primary Care. Psychiatric Services. 2011. http://ps.psychiatryonline.org/article.aspx?articleID=102300.
As it is visible in the chart, although there were more African Americans tested than Caucasians, 111 vs 95, there is still a higher number overall and percentage of Caucasians that received both antidepressants and/or psychotherapy. The tendency for Caucasians to seek professional help seems to be a more common event than for those of other races. This may be due to the African Americans having a tendency to seek advice in pastors, or peers rather than seeing a therapist. Or perhaps there is an issue of lack of insurance coverage. Many psychotherapists are located in higher socioeconomic areas. Perhaps the statistics are not accurate as they can only track those people that have actually seeked help. If more Caucasians have seeked help the stats that state that they have high depression overall or when associated with schizophrenia, may not be accurate, in fact probably are not.
Assuming that they were accurate results for a minute, there is not much evidence linking the issues to genetics. How issues are handled are often a cultural topic. Socially acceptable behavior for one neighborhood may be to see a therapist, while in another it is to discuss problems with a priest. The background and geographic influences seem to be more of a cause for these differences than genetics.
Kasckow, John, M.D., Ph.D.; Erin Ingram, B.A.; Charlotte Brown, Ph.D., 2011. Differences in Treatment Attitudes Between Depressed African-American and Caucasian Veterans in Primary Care. Psychiatric Services, VOL. 62, No. 4. ps.62.4.426.
Psychiatry/Mental Health. 2012. Depression Detection and Treatment Disparity Among Racial Lines. January.