Symptoms of Depression
The onset of the first episode of major depressive disorder may not be obvious if it is gradual or mild. The symptoms of this disorder characteristically represent a significant change from how a person functioned before the illness. The symptoms of depression may include:
- feelings of worthlessness, hopelessness, helplessness or guilt
- persistently sad or irritable mood
- pronounced changes in sleep habits and energy levels
- pessimistic feelings about the future
- trouble making decisions
- significant weight gain or loss
- difficulty thinking or concentrating
- low libido
- increased agitation
- lack of interest in or pleasure from activities typically enjoyed
- recurrent thoughts of death and/or suicide
When several of these symptoms occur at the same time, or last longer than two weeks, and interfere with ordinary functioning, individuals should seek professional advice and treatment. If left untreated, major depression can lead to attempted suicide.
Causes of Depression
Scientists have not yet determined the root cause of major depression. However, there is strong evidence there may be several contributors to the illness. Psychological, biological, genetic and environmental factors may all contribute to its development. Whatever the specific causes, research has firmly established that major depression is a bio-chemical-electrical-neuronal disorder. We also know there is abnormal electrical activity in the brain areas associated with mood regulation. If depression is left untreated, there can also be neuronal degeneration. TMS therapy helps the neurons electrically to fire correctly and thus reversing the loss of neuronal biochemicals and cell connections.
Serotonin, norepinephrine and dopamine are three neurotransmitters (chemical messengers that transmit electrical signals between brain cells) thought to be involved with major depression. Several theories attempting to explain depression are based on an imbalance of these chemical messengers. It is thought that most antidepressant medications work by increasing the availability of neurotransmitters or by changing the sensitivity of the receptors for these chemicals.
Scientists have also found evidence of a genetic predisposition to major depression. There is an increased risk of developing depression when there is a family history of the illness. Not everyone with a genetic predisposition develops depression, but some people probably have a biological make-up that leaves them particularly vulnerable to developing depression. Life events, such as the death of a loved one, chronic stress, and alcohol and drug abuse, may trigger episodes of depression. Some illnesses such as heart disease and cancer and some medications may also trigger a depressive episode. Often, however, depressive episodes occur spontaneously and are not triggered by a life crisis or physical illness.