ABCD Study: KSADS diagnoses for mood disorders at baseline missing?

I am trying to visualize values of the mood disorder KSADS data elements from the structures ‘abcd_ksad01’ (parent report) and ‘abcd_ksad501’ (youth report). While I am able to read in the values for any of the symptoms, such as ‘ksads_1_5_t’ being Symptom - Anhedonia, Present, when I do the same for any of the mood disorder diagnoses, such as ‘ksads_1_840_t’ being Diagnosis - Major Depressive Disorder Present, I only get ‘nan’ values. Could someone help me make sense of this?