According to DSM-IV-TR, the prevalence of the disorder is estimated to be from 2 to 8 percent of the general population. Women are diagnosed with the disorder twice as often as men, and single women are generally overly represented as most at risk. In children and adolescents, boys and girls are equally diagnosed with adjustment disorders. The disorders can occur at any age but are most frequently diagnosed in adolescents. Among adolescents of either sex, common precipitating stresses are school problems, parental rejection and divorce, and substance abuse. Among adults, common precipitating stresses are marital problems, divorce, moving to a new environment, and financial problems.

Adjustment disorders are among the most common psychiatric diagnoses for disorders of patients hospitalized for medical and surgical problems. In one study, 5 percent of persons admitted to a hospital over a 3-year period were classified as having an adjustment disorder. Up to 50 percent of persons with specific medical problems or stressors have been diagnosed with adjustment disorders. Furthermore, 10 to 30 percent of mental health outpatients and up to 12 percent of general hospital inpatients referred for mental health consultations have been diagnosed with adjustment disorders.

By definition, an adjustment disorder is precipitated by one or more stressors. The severity of the stressor or stressors does not always predict the severity of the disorder; the stressor severity is a complex function of degree, quantity, duration, reversibility, environment, and personal context. For example, the loss of a parent is different for a child 10 years of age than for a person 40 years of age. Personality organization and cultural or group norms and values also contribute to the disproportionate responses to stressors.

Stressors may be single, such as a divorce or the loss of a job, or multiple, such as the death of a person important to a patient that coincides with the patient’s own physical illness and loss of a job. Stressors may be recurrent, such as seasonal business difficulties, or continuous, such as chronic illness or poverty. A discordant intrafamilial relationship can produce an adjustment disorder that affects the entire family system, or the disorder may be limited to a patient who was perhaps the victim of a crime or who has a physical illness. Sometimes, adjustment disorders occur in a group or community setting and the stressors affect several persons, as in a natural disaster or in racial, social, or religious persecution. Specific developmental stages, such as beginning school, leaving home, getting married, becoming a parent, failing to achieve occupational goals, having the last child leave home, and retiring, are often associated with adjustment disorders.