Depression, major
Also known as unipolar disorder, major depression is a syndrome of persistently sad, dysphoric mood accompanied by disturbances in sleep and appetite, lethargy, and an inability to experience pleasure (anhedonia). Major depression occurs in 3% to 5% of adults, affecting all racial, ethnic, and socioeconomic groups. It affects both sexes but is more common in women. (See Depression.)
About half of all depressed patients experience a single episode and recover completely; the rest have at least one recurrence. Major depression can profoundly alter social, family, and occupational functioning.
However, suicide is the most serious complication of major depression, resulting when the patient’s feelings of worthlessness, guilt, and hopelessness are so overwhelming that he no longer considers life worth living. Nearly twice as many women as men attempt suicide, but men are far more likely to succeed.
Gender Influence: DepressionGender plays a significant role in clinical depression, as women are twice as likely as men to experience a major depressive episode. Men have a 5% to 12% lifetime risk factor, whereas women have a 10% to 25% risk factor.
Causes
One cause for this difference is the link between rates of depression and levels of sex hormones. Changes in gonadal hormones caused by puberty, menses, and pregnancy, disturbances in the hypothalamic-pituitary-gonadal (HPG) axis, and the effects on neuromodulators such as serotonin may be the key mechanisms in the initiation of depression in women. For example, it’s known that changes in estrogen and progesterone levels (as well as changes in the HPG axis) are associated with pregnancy and delivery; these factors may underlie postpartum depression.
Treatment
Therapies include psychotherapy and antidepressants, which are equally effective for mild and moderate depression but fail in up to 35% of individuals. Alternative therapies (herbal agents, acupuncture, exercise, meditation, and relaxation) remain to be tested for efficacy and safety, especially for women in different age-groups.
Causes
The multiple causes of depression aren’t completely understood. Current research suggests possible genetic, familial,
biochemical, physical, psychological, and social causes.
biochemical, physical, psychological, and social causes.
Dysthymic disorder: A chronic affective disorder
Dysthymic disorder is characterized by a chronic dysphoric mood (irritable mood in children) persisting at least 2 years in adults and 1 year in children and adolescents.
Signs and symptoms
During periods of depression, the patient may also experience poor appetite or overeating, insomnia or hypersomnia, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, and feelings of hopelessness.
Diagnosis
Dysthymic disorder is confirmed when the patient exhibits at least two of the symptoms listed above nearly every day, with intervening normal moods lasting no more than 2 months during a 2-year period.
The disorder typically begins in childhood, adolescence, or early adulthood and causes only mild social or occupational impairment. In adults, it’s more common in women; in children and adolescents, it’s equally common in both sexes.
Psychological factors
Such causes may include feelings of helplessness and vulnerability, anger, hopelessness and pessimism, and low self-esteem; they may be related to abnormal character and behavior patterns and troubled personal relationships.
In many patients, the history identifies a specific personal loss or severe stressor that probably interacts with the person’s predisposition to provoke major depression.
Medical conditions
Depression may be secondary to a specific medical condition—for example, metabolic disturbances, such as hypoxia and hypercalcemia; endocrine disorders, such as diabetes and Cushing’s disease; neurologic diseases, such as Parkinson’s and Alzheimer’s disease; and cancer, especially of the pancreas.
Other medical conditions that may underlie depression include viral and bacterial infections, such as influenza and pneumonia; cardiovascular disorders such as heart failure; pulmonary disorders such as chronic obstructive pulmonary disease; musculoskeletal disorders such as degenerative arthritis; GI disorders such as irritable bowel syndrome; genitourinary problems such as incontinence; collagen vascular diseases such as lupus; and anemias.
Drugs
Drugs prescribed for medical and psychiatric conditions as well as many commonly abused substances, can also cause depression. Examples include antihypertensives, psychotropics, narcotic and nonnarcotic analgesics, antiparkinsonian drugs, numerous cardiovascular medications, oral antidiabetics, antimicrobials, steroids, chemotherapeutic agents, cimetidine, and alcohol.
