Concurrent validity of two observer-rated alexithymia measures.

The purposes of the present study were to evaluate 1) the correspondence between two observer-rated alexithymia measures, the Observer Alexithymia Scale and the modified Beth Israel Hospital Psychosomatic Questionnaire (BIQ) and 2) the psychometric properties of both instruments. Clinical and counseling psychologists (N=131) used the two instruments to rate outpatients with various psychiatric diagnoses. Correspondence was excellent; the correlation between the two scales was 0.69. Moreover, Observer Alexithymia Scale and modified BIQ scores are reliable (total and subscale alphas were within acceptable ranges), and both theoretical structures were confirmed. Both instruments can be recommended for alexithymia studies requiring observer ratings.