Maladaptive reactions to identifiable psychosocial stressors occurring within a short time after onset of the stressor. They are manifested by either impairment in social or occupational functioning or by symptoms (depression, anxiety, etc.) that are in excess of a normal and expected reaction to the stressor.
Adaptation of the person to the social environment. Adjustment may take place by adapting the self to the environment or by changing the environment. (From Campbell, Psychiatric Dictionary, 1996).