Background. This paper describes the rationale and methodology
of the first national psychiatric
morbidity surveys to be carried out in Great Britain. The objectives of
the
surveys were to estimate
the prevalence of psychiatric morbidity among adults aged 16–64 living
in Great Britain; to identify
the nature and extent of social disabilities associated with psychiatric
morbidity; to describe the use
of health and social services by people with psychiatric morbidity and
to
investigate the association
between mental illness and potential environmental risk factors in a
household sample.
Methods. Four separate surveys were carried out in order to
meet
the objectives; a private
household sample (N=10108), a sample of institutions caring for
the mentally ill (N=1191), a
sample of homeless people (N=1166), and a supplementary sample
of
patients with psychosis
living in private households (N=350). A two-stage assessment
procedure was used, in which all
subjects were given the Revised Clinical Interview Schedule (CIS-R)
administered by lay interviewers
to assess neurotic symptoms and disorders and a psychosis screen, including
the Psychosis Screening
Questionnaire. Those who were positive on the psychosis screen were then
interviewed by
psychiatrists using the SCAN (incorporating the tenth edition of the
Present State Examination).
Conclusions. Large scale national surveys such as this augment
the inadequate data on psychiatric
morbidity that are routinely available and are, therefore, an important
source of information upon
which to base policy and generate aetiological hypotheses. These surveys
provide a possible model for similar surveys in other countries.