Background: Although most personality constructs have been standardized in population studies, cyclothymic, depressive, irritable and hyperthymic temperaments putatively linked to mood disorders have been classically derived from clinical observations.
Methods: We therefore administered the semi-structured affective temperament schedule of Memphis, Pisa, Paris and San Diego, Interview version (TEMPS-I) -- in its original University of Tennessee operationalization -- to 1010 Italian students aged between 14 and 26. The interview, administered in a randomized format, took 20 min per subject.
Results: The semi-structured interview was easy to administer and well accepted by subjects, with no refusals. Principal component analysis with varimax rotation confirmed the hypothesized four-dimensional factor structure of the interview, with good to excellent internal consistency. Furthermore, discriminant analysis and multiple regression provided suggestions for identifying the traits that are most useful in defining a weighted cut-off for each of the temperaments (and which, with minor exceptions, are in agreement with those previously proposed on clinical grounds). In an additional exploratory factorial analysis, a depressive type which loads negatively on hyperthymia was distinguished from cyclothymia; the irritable temperament did not appear to have significant loading on either factor.
Limitation: All the present analyses were internal to the scale itself, but ongoing studies are comparing them with other systems of temperament as well as testing their clinical cogency for affectively ill populations.
Conclusion: While more work needs to be done on better operationalization of the irritable temperament, our findings overall support the existence -- in a relatively young nonpatient population -- of cyclothymic, depressive and hyperthymic types according to the classic descriptions of Kraepelin, Kretschmer and Schneider, in their TEMPS-I operationalization.
Clinical implications: Coupled with a previous report identifying 10% of the same 14-26-year-old nonpatient population meeting an empirically defined statistical cut-off for these temperaments, the present data define the putative 'fundamental states' that Kraepelin considered to be the personal predisposing anlagé of major affective disorders.