THE MAJOR functional psychoses presently include schizophrenia, the paranoid states, and the affective disorders.1 To a considerable extent these categories are defined in terms of current symptoms and behaviors, although life history data represent important differentia. For this reason it becomes important to establish more precisely the structure and nature of the dimensions involved. No doubt this is also why psychiatric rating scales are so generally applied in evaluating the therapeutic efficacy of drug treatments. The scales reflect in quantitative form the behavioral profile upon which psychiatric diagnosis is based, after due consideration of type of onset, previous history, recurrency, and related criteria.
There have been several recent efforts2-4 to define the major psychotic disorders entirely in terms of current disturbances of thinking, mood, and behavior. Each of these studies utilized rating scales as measuring devices, obtained its observations within
Lorr M, Klett CJ. Major Psychotic DisordersA Cross-Cultural Study. Arch Gen Psychiatry. 1968;19(6):652-658. doi:10.1001/archpsyc.1968.01740120012002