Biology 103
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"Clinical Depression", also known as "Major Depression" or "Depression", is defined as a "mood disorder that may occur only once in a person's lifetime, or in clusters of "episodes" that typically last 9-16 months."(1) This is a topic I feel must be brought out into the open as not many people who suffer from it realize that they are going through it. Those who are fortunate enough to have people to talk to have an opportunity to help themselves but there are many who do not even know of the existence of this illness. With this paper, I aim to show how depression differs from the sadness or gloom everyone goes through at some period in their lives. Along with that, I also aim to show that depression is not at all uncommon and as extraordinary as people feel and think it to be.

What many fail to understand is depression is indeed an illness, which can and must be treated. It is not a phase of some sort, which one can pass through, or get rid off without taking proper measures. Depression is a serious issue, since it can have harmful affect on one's life; the way a person eats, sleeps and feels about self as well as things. If depression is not treated, symptoms could last for weeks, months, or years and this, without doubt, would have detrimental effects to one's mental and physical health. Another false view about depression is that if it is severe, it has no treatment. In fact, 80% of all reported cases have received effective treatment.(5)

WHAT CAUSES DEPRESSION: THE ARGUMENT OF NATURE VS. NURTURE

There are many factors, which do not directly cause depression but may trigger it. For instance, a stressful event or period in one's life such as due to death of a loved one or the loss of one's job may be the onset of a depression. Aside from events, medications or withdrawal from them could help trigger depression. Also, AIDS, endocrine disorders (hypothyroidism, diabetes), head injury, neurological disorders, infections, emotion or physical trauma and postpartum depression are examples of medical or physiological causes of depression. (1)

Usually, the first episode of depression is a result of a trigger such as a stressful event but the following episodes may occur without a stress event to trigger them. Thus, one can ask the question whether depression is a genetic predisposition that is then triggered by environmental factors. This question, is rather difficult to answer since studies have shown to support both the environmental and the biological perspectives.(2)

Genetic research has also been able to show support that biological elements may play a strong role in depression. Close-blooded relatives of people with depressive disorders were found to be more vulnerable to depression in comparison to members of the general population. For example, studies on identical twins, who share the same genetic make up and fraternal twins, who do not share the exact genetic make up support the view that biology is a big factor in the causes of depression. Some types of depression run in families and those who get ill have a different genetic makeup in comparison to those who do not get ill. But then, it also turns out that people with this particular genetic makeup do not necessarily acquire the illness. Thus, this is where external factors such as stress step in. In other cases, major depression may occur to those who "inherit" it but then there are those who fall into depression without having a family history of depression. (3)

Other than such environmental or external triggers, the root cause of depression is a chemical imbalance in the brain involving the neurotransmitters dopamine, norepinephrine, and serotonin. When there are low levels of these brain chemicals, normal brain transmission of signals by the nerve cells is prevented. In the most primitive part of the brain, the brainstem, there lies a cluster of serotonin neurons. This neurotransmitter is responsible for controlling the important physiological aspects of the body. Included among these aspects are motor activity, cardiovascular activity, respiration, and control of body temperature.(7)

Thus, this "imbalance" causes disturbances in brain circuits and is the main reason why depression can be such a debilitating disorder. There has been extensive research done in the past 20 years by genetic researchers in order to identify the genes that cause depression. At present, these genes have not been identified and one reason may be that several genes contribute to the problem. This means that each gene makes a small contribution and is therefore, hard to spot. Another biological cause of depression is in cases of hormonal abnormalities. When given a number of substances that normally induce the release of growth hormones, depressed patients did not respond positively.(2)

Although there is no doubt that many studies give strong evidence towards biological causes of depression, there are many cases where the chemical imbalances in the brain have disappeared when psychotherapy are completed without the intake of any medications. This suggests that the reverse might be true in which the psychological depression is causing the body to respond physically rather than these imbalances causing the psychological depression.(5)

SYMPTOMS

Depression may result in the inability of a person to take pleasure in anything as well as be unable to perform even the most ordinary tasks.(1) Depressed individuals, in fact two-thirds of them, often think of committing suicide. (7) These individuals feel guilty as well as feeling worthless.(2) Clear thinking is diminished and in place, anxiety, lack of energy and enthusiasm take place. Depression can shut down the survival instinct or temporarily suppress it. Suicide and self-harm are ways to escape from mental pain for depressed individuals. In comparison to "normal" individuals who have suicidal tendencies due to a crisis of some sort, depressed individuals may not care to plan and are willing to attempt more painful and immediate means, such as jumping out of a window. As one loses the motivation to do anything, health deteriorates as sleep and eating disorders arise. (6) Like other devastating illnesses, depression has its stigma attached to it and thus, the patient feels weak and guilty due to his depressed state.

ALARMING FACTS AND FIGURES

330 million people worldwide suffer from depression of which only a few will receive proper treatment or attention. It is estimated that by the year 2020 major depression will be the world's second most debilitating disease, surpassed only by cardiovascular disease.(4) Depression occurs twice as often in women as it does in men. Many factors such as menstruation, pregnancy, miscarriage and menopause may be reasons for depression in women. With additional responsibilities such as taking care of children and going to work or taking care of aging parents, women are highly susceptible to depression.

Depressive symptoms in older people are often not detected as it is thought of as natural for the elderly to get depressed. As for children who are depressed, the symptoms are also not recognized easily as it is a common misconception that depression only occurs in adults.

TREATMENT

First and foremost, detection and measures towards treatment are important when depression occurs. Showing the major symptoms such as lack of motivation or enthusiasm for things previously enjoyed, are a sign. Depression should be treated as a disease and not as an everyday, regular emotion. A psychiatrist is important in evaluating the patient as well as someone who will listen to the patient. Anti-depressant drugs can also help make psychotherapy more effective. It is especially beneficial for those who are too depressed to speak since their symptoms improve after taking medication.(5) Prozac, or fluoxetine, is the most widely prescribed anti-depressant which increases the supply of serotonin to the brain.(6)

Electroshock (ECT or Electroconvulsive Therapy), although having a notorious reputation, is a much better option today than ever. The voltages used today are much lower, safer, and patients are sedated prior to receiving ECT so their muscles will not spasm. ECT and anti-depressant drugs both affect the neurotransmitters in the brain as a way to treat depression.(6)

CONCLUSION

A study done recently by Health Magazine in April of this year found that chronic stress contributes to depression, which led researchers to believe that continuous stress over a long period of time "hard wires" the brain into operating in stress mode all the time, triggering depression.(1) This is a prime example of the confusing principal behind what causes depression. Stress can be considered a symptom, or the result of depression, but this study showed that it actually caused depression. Therefore, it seems that no matter how depression stems, it is important to take notice of the fact that psychological and physical problems thrive on each other and grow. This is why a combination of physical and psychological intervention seems most effective for most patients.(6)

Although we have gathered much evidence to support all the causes of depression, we are left with being unsure to what extent the three causes, genetic, chemical and hormonal play or fit together. Also, the evidence that these causes do not always fit together leaves us with more questions. Thus, in the meantime, we must gather as much evidence in order to come up with effective treatment with the least possible side-effects and prolonged positive effects. Although most sufferers of depression can be helped, they are not aware of this and consequently, many do not seek treatment. To raise more awareness on depression, should be another goal in order to fight depression. The first and foremost step into treating depression is recognizing its symptoms and realizing that this disease can happen to anyone, regardless of his or her background.

WWW Sources

2)The Neurobiology of Depression (Scientific American Journal) ,Neurobiological Views on Depression

3)Depression Information Center ,A Clear Explanation of Depression and Facts and Figures Relation to Depression

4)Action Against Depresion (AAD) , A Page on Seeking Help for Depressed Individuals

5)Psychology Informaiton Online , Depression as a Psychological Disorder

6)Causes of Depression , A Q and A on the Causes of Depression

7)Major Depression and the Neurotransmitter Serotonin , An Explanation on Neurotransmitters

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