Who is the respondent in ATUS?

I want to know who in the household took the ATUS. I searched the variables available but I couldn’t find anything related to what I want. There is a variable named RELATE which shows the relationship of family members to ATUS respondent but it doesn’t say who the respondent was. Based on RELATE and SEX of the respondent I can guess who took the survey but I was wondering if there is an easier way to this.

The only additional variable that may be of assistance is RELATE_CPS8, which uses the head of household as the reference person instead of the ATUS respondent. This variable was collected during the CPS survey, which occurs 2-5 months prior to the ATUS interview. As a result, the household structure could have changed within the elapsed time. It is up to the researcher to determine if this lag time between variables is acceptable.

Hope this helps.