Body of Depression
This research article is about depression. It includes peer reviewed articles, an online website, and video from Ted.com. These resources help better understand depression. It discusses the pathophysiology of the disorder and how chemical imbalances of serotonin, dopamine, and norepinephrine contribute to depression. A holistic approach is necessary to properly treat depression due to the many facets. Depression can complicate or start other debilitating conditions such as heart disease and cancer . There are limited tests for diagnosis and is based primarily on clinical manifestations. This disorder is highly stigmatized because there are no definitive tests that prove this disorder.
Feelings of depression
The World Health Organization (WHO) describes depression as a mood disorder characterized by specific symptoms including sadness, loss of interest, anhedonia (loss of pleasure), lack of appetite, feelings of guilt, low self-esteem or self-worth, sleep disturbance, feelings of tiredness, and poor concentration. Those suffering with this condition report feeling helplessness and/or hopelessness, unable to concentrate, insomnia, decrease in appetite and loss of interest in hobbies or things they would normally enjoy. Sadness, guilt, obsessive thoughts about death and suicide are also common. Depression can affect a person’s ability to function in day to day to life; making it difficult to have healthy relationships and work at a job. (Jesulola, Micalos, & Baguley, 2018) Depression can exacerbate issues concerning physical and mental health. For many, this condition comes and goes, and it is more likely to occur or be experienced at certain stages of a person’s life. Some types of depression are influenced by genetic and biological factors, while others are in response to major life events. It can be triggered by almost anything life altering such as a death of a loved one, losing a job, childhood abuse, relationship issues, and the list goes on.
Pathophysiology of depression
Despite continued research, understanding the pathophysiology of depression is difficult due to the complex phenomenon and the many causes and factors. A holistic approach is necessary in order to properly diagnose and treat this disorder. Poor understanding of the pathophysiology explains why many interventions do not reach its full potential.
The Biogenic amine hypothesis, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and genetic and environmental factors all contribute to the diagnosis of. Other possible contributors include neurogenesis, increased inflammatory cytokines secretion (immunologic factors), elevated levels of corticotrophin-releasing factor (CRF), and abnormalities of second messenger systems. (Jesulola, Micalos, & Baguley, 2018) The brain is the most complex organ in the body and contains many types neurons. Noradrenergic neurons involve norepinephrine (NE) and affects memory, behavior and attention. Serotonin (5-hydroxytryptamine: 5HT) affects all parts of the brain and is the “largest cohesive neurotransmitter system in the brain”. Dopamine (DA) also affects memory and attention along with “reward and motivation functions”. These neurons are linked to symptoms of depression, such as decreased mood, fatigue, vigilance, agitation, decreased motivation and retardation. Changes in serotonin level is linked to sleep, pain response, sex, body temperature, appetite, and circadian rhythm. Patient who suffer with depression have much lower levels of serotonin than non-depressed patients. Reduced availability of serotonin, dopamine, and norepinephrine results in decreased neurotransmission and altered cognitive performance; all of which can lead to depression. (Jesulola, Micalos, & Baguley, 2018)
Factors influencing the pathogenesis of the disorder
Biological factors include age, gender, genetic susceptibility, inflammation, and alterations in serotonergic pathways, noradrenergic pathways, and dopaminergic pathways. (Das & G.K., 2018)
Psychological factors include stroke induced disabilities, low self-esteem, stress, social isolation, having to depend on other for care, and extensive exposure to one or more negative life altering events. (Das & G.K., 2018) Depression can be genetic. If there is a familial history, developing this condition is more likely. Family, twin and adoption studies, and epidemiological evidence provide convincing evidence for a genetic contribution to the development of depression, with heritability appearing significantly greater in women than in men, corroborating the higher incidence and prevalence of most forms of depression in women. Genes associated with the development of depression are apolipoprotein E, the serotonin transporter methylenetetrahydrofolate reductase, guanine, the dopamine receptor gene, and dopamine transporter. (Jesulola, Micalos, & Baguley, 2018)
Environmental stress such as major life events can influence the development and severity of depression as well. Stress has a significant role in precipitating and influencing the clinical course of depression. Depression relapse is common if stressful life events are not improved. Experimental animal studies show structural and functional changes occur within the brain due to stress. Changes in the prefrontal cortex, hippocampus, amygdala, and nucleus accumbens contribute to the development of depression. (Jesulola, Micalos, & Baguley, 2018)
Prevalence and Incidence
One in ten people are affected by depression in any given year; which is over 18 million adults. It is the leading cause of disability for ages 15-44. Over 41,000 people die from suicide every 13 minutes. (Hope for Depression) More than 350 million people of all ages suffer from depression. The World Mental Health Survey conducted in 17 countries found that 1 in 17 people reported at least one episode of depression in the previous year. Depression usually begins during teenage years and carries over into adulthood. Women are generally affected more than men, especially those during child bearing age due to post-partum depression. (Jesulola, Micalos, & Baguley, 2018)
Up to 80% of depressed people have some form of impairment in their daily functioning. Depression affects the economy as well. Productivity is reduced by 20% in the workplace which adds up to about 6 hours per week. There is a higher incidence of unemployment amongst depressed people. Decreased leads to a loss of $30.1–$51.5 billion annually, due poor work performance associated with depression. Many other chronic physical illnesses develop due to the contribution of depression such as diabetes, asthmas, chronic pain, heart disease, hypertension, respiratory disorder, and so much more. Depression remain the leading cause of disability worldwide. (Jesulola, Micalos, & Baguley, 2018)
Contents of the video
In a video I watched on TED.com, comedian Ruby Wax was institutionalized for clinical depression. She discusses how hers and other mental illnesses affect so many people. “1 and 4 people suffer from some form of mental illness” (Wax, 2012) Genetics play a huge role in the development on depression. She believes her depression was inherited from her mother. Although a serious matter, she uses humor to make others better understand the pathophysiology and struggles a person endures with a mental illness. She explains how depression is misconceived as something someone can just get over. Often friends would tell her to “perk up” as if it was just that simple. Because this condition lacks proof by diagnostic and laboratory studies, there is a stigma associated. She used an analogy to explain how humans from centuries ago dealt with stress compared to now. During stone ages there was a mentality of “kill or be killed, eat or be eaten”. Men of that time would fill up with adrenaline and cortisol if they were under attack. They would kill their predators, their adrenaline would dissipate, and everything neurologically would be back to normal. Modern humans experience similar feelings called flight or flight, which increases their adrenaline and cortisol, but the difference is no chemicals are released but instead internalized. The fuel remains in the body, so there is a constant state of alarm going on from everyday life struggles and mishaps; a “nagging loop”, leading to anxiety and depression. (Wax, 2012)
I can relate to the speaker in the video from Teds regarding friends telling her to snap out of it or “perk up”. I too struggled with depression as a young adult and I could not just snap out of it, no matter how many internal pep talks I had. It got to a point where I needed professional help and medication. People around me did not understand and thought that I was being a “Debbie downer”. Those “friends” began to distance themselves from me due to my negative attitude which led to a deeper depression. The video made me realize how common this illness is and if left untreated it can lead to more serious issues or even suicide.
Aside from my personal life, I deal with depressed patients professionally. Working on a stroke unit, I have come to learn that infarction of certain areas of the brain can lead to depression. Left hemisphere lesions are associated with the highest incidence of stroke compared to other parts of the brain. (Das & G.K., 2018) Paralysis and inability to perform basic functions such as ADLs, also lead to severe depression. “Healthy” and independent one day, and totally incapable the next day can trigger depressive emotions.
Depression is an umbrella term which includes anxiety, PTSD, bipolar disorder, HTN, post-partum, etc. Depression also may be secondary to other major diagnoses such hypothyroidism, stroke, obesity, cancer, HIV and chronic pain. These diseases can make a person feel hopeless and suicidal. Everyone diagnosed is unique in how their condition is managed and treated; there is no one size fits all.
Jesulola, E., Micalos, P., & Baguley, I. J. (2018). Understanding the pathophysiology of depression: From monoamines to the neurogenesis hypothesis model – are we there yet? Behavioural Brain Research, 341, 79–90. https://doi.org/10.1016/j.bbr.2017.12.025
Facts about Depression. (n.d.). Depression is a serious medical condition that is associated with symptoms such as melancholy, loss of pleasure, loss of energy, difficulty in concentrating, and suicidal thoughts. Hope for Depression Research Foundation, Retrieved September 29, 2018, from https://www.hopefordepression.org/depression-facts/
Wax, Ruby. (2012, October 10). What’s so funny about mental illness? Ruby Wax. Retrieved from https://www.youtube.com/watch?v=mbbMLOZjUYI
Das, J., & G.K., R. (2018). Post stroke depression: The sequelae of cerebral stroke. Neuroscience and Biobehavioral Reviews, 90, 104–114. https://doi.org/10.1016/j.neubiorev.2018.04.005