Eight major health states were incorporated in the model:
never depressed;
a history of depression;
a history of depression, still in treatment;
significant depressive symptoms;
significant depressive symptoms, in treatment;
major depression;
major depression, in treatment; and
deceased.
The outcomes that were used as input variables for the model were classified under the following headings:
the point prevalence (related to depression);
the incidence of depression among sub-groups, according to the medical history;
the sensitivity of the screening instrument;
the specificity of the screening instrument;
detection (of depression by method);
referrals to a mental health specialist;
the response to treatment in patients with major depression;
patient utilities for health states;
disutility of antidepressant medication;
the suicide rate; and
the hospitalisation rate.