Major Depressive Disorder, Essay Example

Neurotransmitters

Researchers believe that patients who suffer from major depressive disorder have a chemical imbalance of neurotransmitters serotonin, norepinephrine, and dopamine (Emergence Health Network, n.d.). While it is difficult to actually measure the levels of these chemicals in an individual’s brain, it is believes that the expression of these neurotransmitters influence abnormal behavior by interfering with the physiological capabilities they usually contribute to. For example, serotonin is usually responsible for regulating body functions that include “sleep, aggression, eating, sexual behavior, and mood” (Emergence Health Network, n.d.). Serotonin is down regulated in depression and leads to loss of desire for many of these functions. It is also believed that reduced norepinephrine levels cause mood change and reduced dopamine levels interfere with our reward seeking system so those with lowered dopamine levels are unable to feel pleasure as a consequence of their actions.

Depression and Traumatic Brain Injury

Many forms of depression are more common in those who suffer from traumatic brain injury. According to the Model Systems Knowledge Translation Center, two thirds of people with traumatic brain injury are affected by depression (Model Systems Knowledge Translation Center, n.d.). The team concluded that the traumatic brain injury causes physical changes in the brain, especially in the areas of the brain that control emotions. In addition, the physical injury impacts the expression of neurotransmitters which can lead to a disruption of homeostasis in the brain. As mentioned above, this chemical imbalance causes behavioral change. Lastly, depression could be a consequence of an emotional response to injury that deals directly with an individual’s ability to cope with a traumatic or dehabiltating experience.

Genetics

According to the Stanford School of Medicine, twin studies have been the primary experimental method in determining the heritability of depression (Stanford School of Medicine, n.d.). These studies have concluded that identical twins that already have a twin with depression are at a much higher risk for developing depression compared to non-identical twins. As a consequence, this disease is marked by heredity to some extent. Further studies allowed researchers to conclude that genetics accounts for 40-50% of the disease, while the remaining factors are environmental.

Cognitive Contributions

The twin studies mentioned above allowed researchers to understand that environmental factors play a role in the development of depression. It is therefore important to understand how environmental factors contribute to the certain ways of thinking that cause depression. In the textbook section “From Grief to Depression”, we are made to understand how negative thinking can contribute to depression. In situations where an individual has to deal with a sad situation, such as death of a loved one, the opportunity to sink into depression could ultimately be up to them. Those who are able to cope with death and convince themselves that while the event was sad, they should attempt to get past it, will do better than those who are unable to recognize this. For those who are unable to cope, remembrance of the sad event will continue to bring out negative emotions that will keep them in their depressed state (Chapter 6).

Psychological and Cultural Influences of Depression

Traumatic early childhood experiences are one of the environmental factors that contribute to the appearance of depression in many individuals. When a person with depression recalls these bad memories, it prevents them from allowing themselves to emotionally experience many of the aspects of their currents lives, which causes them to become withdrawn from the things they used to enjoy. The diathesis-stress model explains that certain people are predispositioned to certain behaviors as a consequence of their life experiences. In the situation of depression, the stressor is experienced when the patient is a young child, and this stressor provides the backbone for later development of the illness (Prevention Action, n.d.).

Meanwhile, social and cultural influences can also cause stress on a person that will lead to depression. Often, this is a consequence of the standards that society places on an individual. Other people are responsible for measuring someone’s self-worth and this could be detrimental to the positive thinking of many individuals. In many cases, this leads them to feel that they will never fit in or never be good enough at something even though they’re trying their hardest, which can cause them to withdraw from this society or experience suicidal thoughts.

Case Study

Harrison’s experience with depression likely derived from his childhood. His mother overdosing and dying from drug use was likely a traumatic experience that he revisits frequently. Furthermore, Harrison didn’t receive the nurture he desired from his father, who was strict and critical. In addition, when Harrison’s mother was alive she was often unhappy; demonstrating that she herself may have had problems with depression. As a result of his negative experiences in his youth, Harrison now thinks he’s also a bad parent and husband even though this doesn’t seem to be the case. He thinks of himself what he thought of his parents, which is causing him the depression.

References

Chapter 6.Mood Disorders and Suicide.

Emergence Health Network.(n.d.).Depression: Major Depression & Unipolar Varieties. Retrieved from http://info.emergencehealthnetwork.org/poc/view_doc.php?type=doc&id=12999&cn=5

Model Systems Knowledge Translation Center.(n.d.).Depression After Traumatic Brain Injury. Retrieved from http://www.msktc.org/tbi/factsheets/Depression-After-Traumatic-Brain-Injury

Prevention Action.(n.d.).Diathesis-stress models Retrieved from http://www.preventionaction.org/reference/diathesis-stress-models

Stanford School of Medicine.(n.d.).Major Depression and Genetics. Retrieved from http://depressiongenetics.stanford.edu/mddandgenes.html