THE SEASONAL PATTERN ASSESSMENT QUESTIONNAIRE FOR IDENTIFYING SEASONAL AFFECTIVE-DISORDERS

The SPAQ is a widely used tool for identifying possible cases of recur rent major depressive disorders with a seasonal pattern. However. its test-retest reliability, sensitivity, specificity, positive predictive value, negative predictive value, efficiency and predictive validity have not previously been formally assessed. Forty-seven subjects who f ulfilled the DSMIIIR criteria for a major depressive disorder with a s easonal pattern were traced and re-interviewed after five to eight yea rs. The SPAQ was found to have a positive predictive value of 48% and an efficiency of 57% in identifying cases of SAD confirmed by follow-u p. The test-retest reliability was low. There was a mean difference in seasonality score between the first and second test of 3.17 +/- 4.7 ( mean +/- 1 S.D.). Although the SPAQ is a rapid method of collecting in formation about recent seasonal variation, it has low test-retest reli ability and on its own is unable to predict the seasonality of the fut ure course of illness.