One question that has captured the attention of scientists for many decades relates to the heritability of mental illness — is it caused by genetics or a stressful environment? The research says that both are factors. Studies on major depression, in particular, have been pivotal in uncovering the contributions of genetics and environmental factors to its development.
But how much are genetics a factor? A Stanford University study has shown that you are twice or three times as likely to be diagnosed with depression if you have a parent, or sibling with the diagnosis. The use of twins to study depression provided additional support for genetics playing a role because identical twins were more likely to both have depression, compared to fraternal twins (where not all genes are shared).
In addition, adoption studies have been carried out on siblings that were adopted separately, and demonstrated that environmental and life experiences play a role in developing depression, because siblings with shared genetics did not always develop depression.
So overall, what are these studies telling us? They demonstrate that while genetics are more likely to lead to a predisposition for depression, compared to someone without the genetic background. As well, studies have shown that the right environment or life experiences, among other factors, can prevent it.
As better technologies have emerged, research studies have evolved. A more common study now involves looking at the entire genome, similar to DNA testing companies. In these studies, called genome wide association studies, variants or changes in the sequence of DNA are identified and compared between people with and without depression.
These studies are being carried out in larger and larger groups of people because we are realizing that in depression, and other psychiatric disorders, having the disease is not due to one single gene but many genes which are involved and these large samples are needed to identify them.
Hopefully in the future, there may be an early detection system for depression that could lead to interventions from physicians and therapists. Unfortunately, we are not there yet, and many people do not treat a family history of mental health issues with the same attention they may give to diseases such as diabetes or heart disease. It is important to be mindful of this, to break social taboos about discussing mental health and well-being, and create open and safe environments for discussion.
What are some of the steps that we can take if we notice that things are not feeling right? We should learn to recognize the symptoms of depression. For example: lack of sleep, loss of appetite, and low energy, and seek help or counseling if we notice these. We might also start a conversation with the family doctor who can then refer us to a specialist as needed.
Depression can be treated with different types of therapy. We need to remember that although there are biological factors related to depression and other mental health conditions, which are not under our control, many people have found improvement through therapy, medication, or a combination of both. There are some lifestyle changes that can easily be implemented and have been shown to help with depressive symptoms. These include:
Exercising regularly (for example, walking, running, swimming, yoga, aerobics) for 20-30 minutes
Making an effort to obtain 7-9 hours of quality sleep every night
Eating a healthy diet
Engaging in activities that are relaxing (painting, crafts, reading, meditation)
There is a close connection between sleep and mental health. Many people with mental health conditions have insomnia or other sleep disruptions, and scientists have determined these can have an effect on the brain and lead to impairments in thinking and regulating emotions. Common treatments for insomnia, which can be beneficial to everyone, include having a regular sleep and wake schedule, minimizing distractions in the bedroom (computers, tablets, TV), and keeping the bedroom dark.
These can help to ensure a good night’s sleep, with more deep sleep and minimizing waking up through the night. Exercising regularly can also help you fall asleep faster and physical activity produces endorphins which can act as a natural antidepressant. With regards to diet, studies have found that highly processed foods can increase inflammation, which has been shown to be associated with depression, while diets including whole foods are associated with lower levels of depressive symptoms.
New research into depression, and its underlying causes, will eventually make its way into the clinic to provide help for those who need it. There is a light at the end of the tunnel and we are getting closer with each passing day.