Acute and transient psychotic disorders, as defined by the ICD-10,
are disorders which mainly concern females, with possible onset in all ages of adult life, but usually between the thirtieth and fiftieth year of life. Their onset is acute or even abrupt within 48 hours, but only rarely dependent on acute severe stress in spite of former assumptions. The psychiatric period is very short, with a mean of 17.5 days, in some cases even only one day. Their response to antipsychotic drugs is very good and their outcome is usually favorable in spite of the fact that they are usually recurrent. They differ from schizophrenia regarding the gender distribution, age at onset, premorbid level of functioning and social interactions. The level of postepisodic functioning and outcome is more favourable in ATPD than in schizophrenia