Why do people become clinically depressed? This is like asking - what causes people to become deeply sad? There are some obvious answers and one can cite financial problems, relationship issues, the death of a loved one, divorce, bankruptcy, loss of one's home or business, chronic illness, the stresses of everyday life, and many others as the cause of clinical depression. Indeed, external events such as these can trigger depression. This, however, just scratches the surface. Two persons may experience the same tragic life event, but it can happen that only one becomes clinically depressed, while the other does not. Why is this so?
There are factors, other than the triggering event, that contribute to depression. One of them is heredity. This is in fact the most common risk factor in many illnesses, and it is no different in the case of a major depression. Research has shown that depression tends to run in families. This is especially true concerning bipolar disorder, a type of depression in which the person alternately experiences manic, depressive, and normal moods. But while a susceptibility to depression can be inherited, it does not mean that those without a family history of the disease will not fall prey to it. Anyone can suffer from a major depression, with or without a family history of the condition.
Environmental factors also seem to play an important role in depression. The presence of chronic stress can slowly wear down a person, such that he eventually breaks down and succumbs to depression. It has also been found out that certain groups of people appear to be more susceptible to depression than others. For instance, minority groups who continually experience discrimination, as well as socio-economically disadvantaged sections of society, seem to have higher rates of depression than other people outside their groups.
Biologically, the cause of clinical depression is linked to brain chemistry. There are more than a hundred chemicals, known as neurotransmitters or neurochemicals that circulate in our brain. Four of the most important neurochemicals are norepinephrine, serotonin, dopamine, and acetylcholine. An imbalance in these chemicals results in certain neuro-psychiatric illnesses such as Parkinson's disease and dementia. People with this condition have decreased levels of serotonin and norepinephrine.
Food, medication and activity all have an effect on the neurotransmitters in our brain. As such, having a balanced diet and getting enough exercise and sleep are important considerations for people with depression. They must also bear in mind that certain medications may cause depression as a side effect. In particular, some medications for the treatment of cancer, seizures, high blood pressure and acute pain can all have a depressive side effect. Even certain contraceptives, sleeping pills and anti-anxiety medications can contribute to the development of depression. This underlines the importance of not self-medicating, and of strictly following physician's instructions regarding medication.
As can be seen, there are a variety of factors that come into play in clinical depression. Some of them are beyond our control, such as heredity, genetics and ethnicity or the group in society in which one is born. Death, debts, money issues, calamities, unwelcome life changes and such external triggers of depression are also often beyond anyone's control. Depression may then be an unavoidable part of life sometimes, but it can be managed and treated, just like any other medical condition.