-9999 = Missing
-8888 = Question not asked
-7777 = Form updated during study, question not on new form
-6666 = Participant failed to complete
-3333 = Not applicable, nested question
-2222 = Question not applicable
-1111 = Participant deceased

PTNUM <= 3000 (FILTER)
-9999 = Missing
-8888 = Question not asked
-7777 = Form updated during study, question not on new form
-6666 = Participant failed to complete
-3333 = Not applicable, nested question
-2222 = Question not applicable
-1111 = Participant deceased
0 = Not Selected
1 = Selected

Depressed mood (Hamilton, intake, CE)
-9999 = Missing
-8888 = Question not asked
-7777 = Form updated during study, question not on new form
-6666 = Participant failed to complete
-3333 = Not applicable, nested question
-2222 = Question not applicable
-1111 = Participant deceased
0 = Not present
1 = Mild
2 = Moderate
3 = Severe
4 = Very severe