Depression is a serious, yet common, mood disorder, with the ability to, severely impact one’s capability to preform necessary daily life activities. In 2016, in the United States, 6.7% of adults and 12.8% of adolescents (ages 12 to 17) had at least one major depressive episode. (Data from 2013 National Survey on Drug Use and Health) Overall, one in six people or 16.6% will experience some form of depression in their lifetime.
It is important to note that depression occur at any age, even if it is most common amongst teens, and those in their early twenties and thirties, and is can often co-occur with other serious medical conditions such as diabetes, cancer, heart disease, and Parkinson’s disease. Depression, these diseases, and medication taken for both diseases, have the ability to cause potentially harmful side effects, that may contribute to an increase in the symptoms of depression. (U.S. Department of Health and Human Services, 2015) In addition, depression may frequency occur with other psychological illnesses such as substance- related disorders, panic disorder, obsessive-compulsive disorder, anorexia nervosa, bulimia nervosa, and borderline personality disorder. (American Psychiatric Association, 2013) Consultation with an experienced physician is needed in all cases were depression is present, but it is emphasized when multiple conditions co-occur.
Depression can have a variety of mental and physical symptoms that mainly stem from an overwhelming feeling of sadness and loss of interest, that leads to a decrease in the person’s overall ability to function. Other symptoms may include, “loss of interest or pleasure in activities once enjoyed, changes in appetite, such as weight loss or gain unrelated to dieting, trouble sleeping or sleeping too much, loss of energy or increased fatigue, increase in purposeless physical activity, such as slowed movements and speech, feeling worthless or guilty, difficulty thinking, concentrating or making decisions, and thoughts of death or suicide” (American Psychiatric Association, 2017) In order for depression to be diagnosed, two or more symptoms must be present for at least two weeks prior to the diagnostic session.
Some medical conditions like thyroid problems, a brain tumor, and vitamin deficiency have the ability to mimic the symptoms of depression and thus is important that physicians take a wholistic approach to diagnosing depression. In addition, patients with depression express symptoms differently depending on the frequency, severity, and length that which they experience their symptoms. When physicians are looking to diagnosis depression they may perform an interview and physical examination. In some cases, a blood test might be done to make sure the patient’s symptoms are not due to a different medical issue such as a thyroid problem. (American Psychiatric Association, 2017) Physicians may also ask questions that look to identify specific symptoms, medical conditions, family medical background, and cultural and environmental factors. This will allow them to successfully diagnose the patient and develop a treatment plan.
Depression can be successfully treated and it is considered to be one of the most treatable mental disorders as, “between 80 percent and 90 percent of people with depression eventually respond well to treatment.” (American Psychiatric Association, 2017) The most common treatments include medication such as antidepressants, aimed at altering one’s brain chemistry, and psychotherapy, or cognitive behavioral therapy, that is aimed at helping people recognize distorted thinking and change their behaviors and thinking. Experimental treatment methods, such as Electroconvulsive Therapy, or a brief electrical stimulation of the brain while the patient is under anesthesia and administered a muscle relaxant, are implemented in extreme cases where patients have not responded to other treatments. Patients are often recommended to use a combination of these treatment methods in order to receive the best results. In addition, most treatments require a certain degree of trial and error as multiple attempts are typically required in order to find the treatment that is going to be the most affective, for each individual patient.
Although, medical methods have been found affective in the treatment of depression, many self-help and coping mechanisms are recommended in order to aid in the reduction of symptoms. Patients are encouraged to be active and to exercise, as well as to get enough sleep, and consume a healthy diet, in order to naturally improve one’s overall mood. Patients are also told to set realistic goals and to break up large tasks into smaller ones in order to feel a sense of achievement when they accomplish a given goal or task. They are recommended to seek out trusted friend to maintain frequent communication with, and to put off making major and important life decisions, until they feel better. Those suffering from depression are recommended to avoid alcohol, as it is as a depressant, and can often bring down one’s mood. In addition, it is always important for patients to educate themselves about any illness that they are experiencing, and the same is true for depression as patients are recommended to gain a better understanding of their illness.
It is difficult to pinpoint those who are at risk for depression as it can affect anyone, but research does highlight the fact that those with, “high levels of anxiety as a child, could mean a higher risk of depression as an adult.” (U.S. Department of Health and Human Services, 2015) This may be due to the fact that the exact cause of depression is still unknown, but it has the ability to variate between individual patients, as many factors may play a role in depression, including genetics, brain biology and chemistry, and life events such as trauma, loss of a loved one, a difficult relationship, an early childhood experience, or any stressful situation. (U.S. Department of Health and Human Services, 2015) In addition, there is growing evidence to support the idea that stressful life events may be triggers for epigenetic modification that have the potential to influence one’s risk for developing depression.
Epigenetic modifications, caused by environmental and cellular events, lead to changes in gene expression and suppression, as well as chromatin structure, without altering the nucleotide sequences of DNA. While the DNA contains the genetic information, epigenetics control how this information is expressed through the modification of histone proteins, that have the potential to control chromatin organization and DNA methylation. “Epigenetics refers to how both the external environment and internal physiologic environment can interact with the nuclear DNA of every single cell in the body, to alter how these cells function.” (Conti CL, 2016)
When considering mood disorders, such as depression, that have been extensively researched, it is considered to be unlikely that on whether one single gene is responsible for the illness. Instead it is purposed that one inherits a susceptibility for depression through multiple genes and “the genetic material within the nucleus of brain cells must first be influenced by factors that come from outside the brain, such as external environmental or influenced by physiologic factors that come from inside the body that can interact with these susceptibility genes,” (Conti CL, 2016) to cause psychiatric illness such as depression.
It is suspected that “stressful experiences are able to cause methylation in the promoter region of the glucocorticoid receptor gene characterizing an epigenetic modification, then the negative feedback by cortisol released by adrenal will be disrupted altering the hypothalamic-pituitary-adrenal (HPA) axis, increasing the risk to develop depression.” (Conti CL) Although, more research is needed to determine the roles of DNA methylation and neuroprotective proteins in depression, we are able to conclude that through epigenetic mechanisms, traumatic or stressful occurrences in early stages of life, predispose people to an increased chance of experiencing depression in adulthood.
This approach, coincides with previous research, that suggests the serotonin transporter gene is affected by stressful environmental events, and has been linked to depression. Despite the relevancy of the information, it is important to keep in mind that any possible genetic and epigenetic contributions are likely combinations of many possible factors that lead to the overall symptoms of depression. Often times those suffering from depression are also dealing with significant stressful life events that alter their overall susceptibility. Internal and external factors have the ability to interact and thus it is difficult to determine what specific epigenetic modification are responsible for depression. In addition, we know little about the genes affected by depression and thus it is difficult to reach a conclusion in regards to specific epigenetic modifications.
This research may potentially be applied to the diagnosis of depression because if specific epigenetic modifications are identified and linked to depression, physicians while be able to develop a test to see if a particular patient has depression. Also, as previously stated, feelings of depression may be aided stressful events, and in some cases, may only appear in times when patient is experiencing the results of those stressful events. If depression linked to specific epigenetic modifications, patients may be potentially able to receive a test to see if they have those specific modifications, and are thus predisposed to an increased risk of experiencing depression.