Depression diagnosis : The first step to obtaining appropriate treatment is a complete physical and psychological evaluation to determine whether the person may have a depressive illness, and if so, what type. Certain medications, as well as some medical conditions, can cause symptoms of depression. Therefore, the examining physician should rule out (exclude) these possibilities through an interview, physical examination, and laboratory tests. A thorough diagnostic evaluation includes a complete history of the patient's symptoms: (1) When did the symptoms start? (2) How long have they lasted? (3) How severe are they? and (4) Have the symptoms occurred before, and, if so, were they treated and what treatment was received? The doctor should ask about alcohol and drug use, and whether the patient has had thoughts about death or suicide. Further, the history should include questions about whether other family members have had a depressive illness, and if treated, what treatments they received and which were effective. A diagnostic evaluation also includes a mental status examination to determine if the patient's speech, thought pattern, or memory has been affected, as often happens in the case of a depressive or manic-depressive illness. As of today, there is no laboratory test, blood test, or X-ray that can diagnose a mental disorder.

Causes of depression : Some types of depression run in families, indicating that a biological vulnerability to depression can be inherited. This seems to be the case especially with bipolar disorder. Studies have been done of families in which members of each generation develop bipolar disorder. The investigators found that those with the illness have a somewhat different genetic makeup than those who do not become ill. However, the reverse is not true. That is, not everybody with the genetic makeup that causes vulnerability to bipolar disorder has the illness. Apparently, additional factors, possibly a stressful environment, are involved in its onset. Major depression also seems to occur in generation after generation in some families, although not as strongly as in Bipolar I or II. Indeed, major depression can also occur in people who have no family history of depression. An external event often seems to initiate an episode of depression. Thus, a serious loss, chronic illness, difficult relationship, financial problem, or any unwelcome change in life patterns can trigger a depressive episode. Very often, a combination of genetic, psychological, and environmental factors is involved in the onset of a depressive disorder. Nothing in the universe is as complex and fascinating as the human brain. The over 100 chemicals that circulate in the brain are known as neurochemicals or neurotransmitters. Much of our research and knowledge, however, has focused on four of these neurochemical systems: norepinephrine, serotonin, dopamine, and acetycholine. In the new millennium, after new discoveries are made, it is possible that these four neurochemicals will be viewed as the "black bile, yellow bile, phlegm, and blood" of the twentieth century. Different neuropsychiatric illnesses seem to be associated with an over-abundance or a lack of some of these neurochemicals in certain parts of the brain. For example, a lack of dopamine at the base of the brain causes Parkinson disease. Alzheimer dementia seems to be related to lower acetylcholine levels in the brain. The addictive disorders are under the influence of the neurochemical dopamine. That is to say, drugs and alcohol work by releasing dopamine in the brain. The dopamine causes euphoria, which is a pleasant sensation. Repeated use of drugs or alcohol, however, desensitizes the dopamine system, which means that the system gets used to the drugs and alcohol. Therefore, a person needs more drugs or alcohol to achieve the same high feeling. Thus, the addicted person takes more and more to feel less and less high. The different types of schizophrenia are associated with an imbalance of dopamine (too much) and serotonin (poorly regulated) in certain areas of the brain. Finally, the depressive disorders appear to be associated with altered brain serotonin and norepinephrine systems. Both of these neurochemicals are lower in depressed people. Please note that I specified, "associated with" instead of, "caused by." I made this distinction because we really don't know whether low levels of neurochemicals in the brain cause depression or whether depression causes low levels of neurochemicals in the brain.

Difficulty concentrating, remembering, making decisions. Persistent physical symptoms that do not respond to treatment, such as headaches, digestive disorders, and chronic pain.

Other causes of depression : Certain medications that alter the levels of norepinephrine or serotonin can alleviate the symptoms of depression. Some medicines that affect both of these neurochemical systems appear to perform even better or faster. Other medications that treat depression primarily affect the other neurochemical systems. The most powerful treatment for depression, electroconvulsive therapy (ECT), is certainly not specific to any particular neurotransmitter system. Rather, ECT, by causing a seizure, produces a generalized brain activity that probably releases massive amounts of all of the neurochemicals. Women are twice as likely to become depressed as men. However, scientists do not know the reason for this difference. Psychological factors also contribute to a person's vulnerability to depression. Thus, persistent deprivation in infancy, physical or sexual abuse, clusters of certain personality traits, and inadequate ways of coping (maladaptive coping mechanisms) all can increase the frequency and severity of depressive disorders, with or without inherited vulnerability. The effect of maternal-fetal stress on depression is currently an exciting area of research. It seems that maternal stress during pregnancy can increase the chance that the child will be prone to depression as an adult, particularly if there is a genetic vulnerability. It is thought that the mother's circulating stress hormones can influence the development of the fetus's brain during pregnancy. This altered fetal brain development occurs in ways that predispose the child to the risk of depression as an adult. Further research is still necessary to clarify how this happens. Again, this situation shows the complex interaction between genetic vulnerability and environmental stress, in this case, the stress of the mother on the fetus.