There is ongoing research into the causes of depression. There are believed to be many factors involved. Family history of depression is a risk factor for developing depression and therefore genetic and environmental factors are believed to play a role although it is important to realize that just because a member of the family has depression, other members may not go on to develop this illness. Developmental, biochemical and social factors are also believed to contribute to this mood disorder.
Several neurotransmitters found in the brain such as norepinephrine (NE), serotonin (5-HT) and dopamine (DA) play a critical function in maintaining normal mood and therefore depletion or upsetting the balance of these neurotransmitters can lead to mood disorders. Increased cortisol levels or decreased thyroid levels are often seen in depressed patients.
Several theories regarding the cause of Seasonal Affective Disorder have been put forth involving circadian rhythm (naturally occurring 24 hour body rhythm) disturbance, high levels of melatonin due to inadequate fall and winter light to break down melatonin, a theory now of questionable validity, or low fall and winter production of the neurotransmitter, serotonin. Further research is ongoing and needed in the area of causes of depression.
A number of medical illnesses can be accompanied by depression such as heart attack, cancer, stroke, and Parkinson’s disease. Generally, although not always, a stressful event, might precipitate a person, with a predisposition to depression to develop an episode. As time goes on and if more episodes develop the stressors able to precipitate illness may be mild or an episode might develop with no stressor present.
Depression in Women It has been estimated that women experience depression twice as often as men.1 This may be due to a number of factors such as the hormonal changes women experience during their cycles, pregnancy, miscarriages, post- partum, and during menopause. Women generally carry more of the home responsibilities than men also. It is not uncommon for women to experience brief period of low mood after the birth of a child. This usually corrects itself within a short period of time and does not require treatment, but in a smaller number of cases women may go on to develop major depressive disorder requiring close physician follow up and treatment.
Depression in Men Although men are less likely to suffer depression than women, they are also less likely to go for treatment and are more successful in suicide attempts resulting in four times the suicide rate of women. Depression is associated with higher coronary heart disease in men and women but only men appear to have an increased death rate due to the heart disease. Symptoms often manifest themselves differently between men and women, with men exhibiting more anger, irritability and discouragement rather than hopelessness or helplessness.2
Depression in the Elderly Unfortunately depression in the elderly can go undiagnosed and untreated. Many people have the mistaken idea that due to the life changes experienced by the elderly that depression is a natural part of growing old. This is not the case. Elderly can be expected to live very satisfying and fulfilling lives. It is not uncommon for the elderly to face difficulties such as grief, a significant move, or medical difficulties that may result in brief periods of low mood. However, the elderly should be expected to have their moods return to normal after these difficulties, as they did in their younger years.
When the elderly experience depression they often report the symptoms in terms of physical ailments as the elderly are often not willing to discuss feelings such as guilt, hopelessness and worthlessness. This can sometimes delay the diagnosis as a physician, of necessity often has to try a number of tests to rule out a physiological reason for the symptoms.
Both medication and psychotherapy (talking therapy) are effective means for treating the elderly patient. Often the combination is more effective than either treatment alone.
Depression in Children Preadolescent and adolescent children can experience depression. Symptoms in younger children are often manifested as physical complaints such as a sore stomach or headache, irritability, and social withdrawal. In younger children depression is often seen in combination with other mental disorders such as Attention-Deficit Hyperactivity Disorder, Behavioral Disorder, or Anxiety Disorder. Recognizing depression in a child can be difficult as a parent can wonder if the sulky behavior, getting in trouble, refusing to go to school and being clingy is just a phase.
Adolescents often report the same symptoms as adults, interrupted sleep, increased desire to sleep, change in appetite, psychomotor retardation (slowed movements), and difficulty with concentration and memory. Since adolescents are often a little moody, grouchy and negative it can be hard to know when they are experiencing depression.
Medication and psychotherapy is used in treating depression in children and adolescents. However, there has been increasing concern regarding the safety of these medications in this age group. It is therefore important for the treating medical person and the parents to watch for signs of increasing thoughts, plans or talk of suicide.