Test Your Knowledge

The cause of depression at any age cannot be narrowed down to a single factor. However, it appears that brain chemistry plays a major role in the disorder. Chemicals within the brain called neurotransmitters convey messages between the nerves.  Too many or too few neurotransmitters, particularly norepinephrine, serotonin and dopamine, are believed to cause alterations in mood.

Many adults may have had depression for many years, or it may develop later in life. It is important to distinguish between normal sadness due to events, such as the loss of a spouse, and symptoms of depression.

There are many risk factors for depression. For instance, women are nearly twice as likely to develop depression as men. Many mental health professionals believe that hormonal changes related to pregnancy, miscarriage, menstruation, the postpartum period, premenopause and menopause may precipitate depression in women.

It is important to note, however, that depression among men may be underdiagnosed as men may be more hesitant than women to share their feelings with others.

Individuals with a personal or family history of depression are also at greater risk of developing the condition. People who have had one episode of major depression have a 60 percent chance of having another episode. According to the National Alliance on Mental Illness (NAMI), the risk of major depression may be as high as 25 percent in first-degree relatives (e.g., parents, children, siblings) of patients with a history of major depression.

Other risk factors for depression include:

• Stressful events or life situations. Individuals who have experienced major stresses, such as the death of a loved one, discrimination, abuse or trauma have an increased risk of depression. Unrealistic or unreachable expectations or life goals or major obstacles (real or perceived) to life goals and expectations may also increase the risk of depression. Retirement, moving out of a family home or moving into a community for older adults are a few examples of stressful events and situations that may affect older adults.
  
  
• Chronic physical medical conditions. The rate of depression among patients hospitalized for general medical illnesses is between 10 and 14 percent, according to the National Mental Health Association (NMHA). The more severe the condition, the greater the risk of major depression. Medical conditions of particular concern include:
  
  
• Heart disease. According to the NMHA, about 18 to 20 percent of patients with coronary disease who have not had a heart attack may be depressed and as many as 40 to 65 percent of heart attack survivors may have major depression.
  
  
• Stroke. The NMHA reports that nearly 25 percent of patients who have a stroke in any given year will also develop major depression.
  
  
• Diabetes. The risk of major depression in patients with adult onset diabetes is as high as 25 percent, according to the NMHA. In addition, as many as 70 percent of patients with diabetic complications, such as kidney failure, may be depressed.
  
  
• Cancer. An estimated one in four people with cancer are depressed, according to the NMHA.
  
  
• Other medical conditions that are associated with depression include the eye disorder macular degeneration, Parkinson’s disease, arthritis and chronic lung disease. Patients who have undergone certain medical procedures (e.g., bypass surgery) are also at an increased risk.
  
  
• Medication use. Numerous medications can produce side effects that include symptoms of depression. In older adults who must often take many medications, these effects may be particularly significant.
  
  
• Other mental health conditions. People with other mental health conditions, including some anxiety disorders and cognitive disorders (e.g., Alzheimer’s disease), are more likely to experience depression.
  
  
• Substance abuse. People who abuse alcohol, drugs or other substances have an increased risk of depression.
  
  
• Marital status, quality of marriage and lack of social supports. Single people have an increased risk for depression. This is particularly true for individuals who have been widowed. According to the NMHA, a third of people who lose a spouse develop depression in the first month after their spouse’s death. About half of these remain depressed after one year. Individuals who feel rejected or depreciated by a loved one, or who have few or no friends, are also at an increased risk for depression.