The nature of 'transient' and 'partial' psychoses: findings from the Northwick Park 'Functional' Psychosis Study

Three hundred and twenty-six consecutively admitted patients with definite or possible functional psychotic illnesses to which no diagnostic classification had been applied were followed up after 2.5 years. In 86 cases symptomatology had been inadequate for the patients to enter the functional psychosis study, and in 75 cases this was because the symptoms were partial or transient. These patients were compared at follow-up with those who fulfilled operational criteria for schizophrenic, affective or schizoaffective psychoses. Differences between the 'partial' cases and those fulfilling specific diagnostic criteria were few, but the transient cases fared significantly better. Although the transient illnesses were recurrent, at follow-up at 2.5 years they appeared to have a good outcome in terms of social variables and symptomatology.