It's absurd that you think advertisers can't generate this information:
1. Get addresses of mental care clinics and offices.
2. Geofence addresses
3. Correlate devices that visited geofence addresses (using LiveRamp data) with devices that saw your ads on Mental Health sites.
4. Bonus, look at the path on the pages to figure out what disease they were viewing when your ad was displayed if you weren't already targeting specific page content.
1. Get addresses of mental care clinics and offices.
2. Geofence addresses
3. Correlate devices that visited geofence addresses (using LiveRamp data) with devices that saw your ads on Mental Health sites.
4. Bonus, look at the path on the pages to figure out what disease they were viewing when your ad was displayed if you weren't already targeting specific page content.