It is well known that depression results from the combination of many different factors. Environmental effects, such as stressful life events, are a trigger in many patients for the development of major depressive disorder (MDD) and the milder disorder, dysthymia. It is also true that the same major stressors will not produce depressive symptoms in some, pointing to underlying risk factors that make some more susceptible to depression than others. Researchers have attempted to identify a single gene that can be linked to MDD, and while familial clustering of depressive disorders is a common finding, single-gene inheritance patterns are not seen. Instead, patterns suggested that several genes are involved in depression, and a recent research study demonstrated the interactive effects of these genes on the disease. Read more →

A study published in Psychological Science evaluated the link between happiness and personality traits in 973 twins. The authors found that happiness was heritable, and that it showed genetic linkage to certain personality traits. Those who were extroverted, open, agreeable and conscientious were more likely to be happy. Moreover, twins who exhibited similar personality traits had similar levels of happiness in a seemingly genetic pattern. Read more →

Post-traumatic stress disorder (PTSD) has been in the news a lot lately, primarily due to the prevalence of PTSD in Iraq war veterans. PTSD can occur following any severely stressful event, and recent research has shown that some individuals are genetically “at-risk” for its development.

A study of adult victims of childhood trauma compared the occurrence of PTSD and genetic variations in the FKBP5 gene, which is related to stress response. Not surprisingly, the study found that both abusive and nonabusive childhood traumatic events were linked to the development of PTSD. In addition, four specific variations of the FKBP5 gene significantly increased the risk of PTSD in child abuse victims. This effect was still present after controlling for depression severity, age, sex, and the occurrence of other kinds of trauma. Read more →

Inflammation is a hot topic in medical research, with studies showing links to heart disease, dementia and longevity. Depression is a relatively new addition to the list of inflammation-associated diseases, with two recent publications demonstrating altered levels of inflammatory molecules in the blood of patients with major depressive disorder (MDD). Both studies evaluated the levels of cytokines in patient’s blood. Read more →

Multiple sclerosis (MS) is a poorly understood disease that affects patients at an early age and, usually, lasts a lifetime. Factors that predispose to the development of MS include genetics, geographic location, sex and birth month, suggesting an interesting nature-nurture interaction in this disease process.

The increased rate of MS at high latitudes has been demonstrated in many studies, with those living in the Northern United States and Canada at a higher risk than those closer to the equator. This geographical influence is most commonly linked to the decreased (UV) radiation in these locations. UV light is a requirement for the production of vitamin D, and it is this effect that is most commonly thought to increase the risk of MS. Read more →

Most long distance runners have experienced the “runner’s high” — a feeling of enhanced mood and relaxation following a strenuous run. Its presence is unmistakable, but also hard to explain, and even harder to scientifically prove. Recently, researchers used high-tech brain imaging to demonstrate changes in brain activity that correlate with this phenomenon. Perhaps more importantly, this runner’s high is also linked to decreased pain perception, providing a potential therapeutic mechanism for sufferers of chronic pain. Read more →