Adjustment disorders are unusual reactions to stressful events or situations. A stressor may be a single event, such as the end of a romantic relationship or loss of a job; or there may be additional stressors at once, such as business difficulties and marital problems. A stressor may be recurring, as with seasonal crises in business, or continuous, such as living in a high crime neighborhood. A stressor may come with specific developmental events, such as going to school, leaving the parental home, getting married, becoming a parent, failing to attain work goals, or retiring.

An Adjustment Disorder generally begins within three months of the stressful event and usually lasts no longer than six months after the stressor or its consequences has stopped. The person may or may not be aware of the stressor causing the disturbance.

Adjustment disorders are common; 5-20% of people in outpatient treatment have a principal diagnosis of Adjustment Disorder. Anyone can be affected, regardless of sex, age, race, or circumstance, but people with disadvantaged living circumstances may be at increased risk, due to the number of stressors they experience.

Adjustment Disorder is not to be confused with Post-Traumatic Stress Syndrome, which usually involves a more severe stressor. When the reaction is an expectable response to the death of a loved one, bereavement is usually diagnosed instead of Adjustment Disorder.