Is Depression Hereditary?

Experts generally agree that our genes help determine the likelihood of depression. It’s believed that the origins of depression could be caused by a mixture of genetic and other factors.

Gender is one of these factors; women are about 75% more likely than men to have experienced depression, and about 60% more likely to have experienced an anxiety disorder. There is likely a complex mixture of factors which contribute to the gender differences, related not just to biological or physiological factors, but social as well. Women have a tendency to view themselves in a more negative way than men do, and that’s a factor for risk of depression.

Genetic depression link

The hormone serotonin serves a crucial role within our brain chemistry. The level of serotonin within the brain has a major affect on our emotions, thinking and behavior. Anti depressants modify the amount of serotonin within the brain. It’s believed that serotonin plays a part in the forming of mental illness. As a result, the level of serotonin which your body makes and keeps seems to be vital in the struggle against depression. The TPH2 gene is a key part in controlling serotonin levels. Experts believe that TPH2 plays a part in the development of psychiatric disorders.[1]

A 2001 analysis of 54 studies has confirmed the serotonin gene’s association with depression. The analysis found that a person’s genetic makeup does matter in how she or he reacts to stress. The analysis supports earlier findings that people who had a less functional short allele on a certain area of the serotonin gene had a more difficult time recovering from trauma compared to those with long alleles.

Scientists have also been looking at the function of TPH2 in the development of manic depression and depression. They’ve compared the genetic variations among people with depression and healthy people. They have observed that TPH2 is involved in the development of manic depression and depression.[2]

Seasonal depression

Miserable weather is not as common a depression factor as is generally believed.

Researchers found that symptoms of depression were not influenced by the time of the year or weather conditions. Still, this research doesn’t negate the existence of seasonal affective disorder, also referred to as SAD, but rather shows that the impact that seasons have on depression could be overestimated.

It’s evident from past studies that seasonal affective disorder exists, but this study indicates that what is usually thought of as the winter blues doesn’t affect us as much as we might think.

Most seasonal depression studies ask individuals to look back on their feelings over a period of time. And although individuals are quite good at remembering certain information and events, they unfortunately can’t accurately remember the timing of day-to-day symptoms and emotions over decades of their lifetime.

So the researchers tried a different approach. Data from a sample of 556 individuals in Iowa and 206 individuals in western Oregon was analyzed. Self-report measures of symptoms of depression multiple times over a period of years were filled out. These data were then compared with local weather conditions, which included sunlight intensity, during the time the reports were completed.

Although a small effect was found by the researchers throughout the winter months, it was more modest than expected if seasonal depression was as common as generally thought.

The power of the winter blues may have been overestimated by the public for several reasons, such as the generally high prevalence of depression, seasonal affective disorder awareness, and also a dislike of the weather in winter.

Although we might not be having as much fun in the winter, feeling cooped up and being less active, it’s not the same as real signs of a clinical depression such as hopelessness, long-lasting sadness, and sleep and appetite problems.

Individuals who believe they have SAD should get help. Antidepressant medication, cognitive behavior therapy, and light box therapy can all help relieve both SAD and depression.