Gregory's ServerAs shown above, Xandr (re)sells 35 lists from different data brokers such as Epsilon, Skydeo or Adstra that are related to 'depression' and contain browser IDs, smartphone device IDs or other personal identifiers on people who are labeled 'depression diagnosis' or 'use Rx treatment for depression', or at least Xandr did so in 2021.
The Markup put the full file on Github and built a tool that makes it easy to search it, e.g. for the term 'divorce'.
https://themarkup.org/privacy/2023/06/08/from-heavy-purchasers-of-pregnancy-tests-to-the-depression-prone-we-found-650000-ways-advertisers-label-you
Advertisers mostly do not get direct access to the raw data. They pay for the ability to exploit massive amounts of personal data within the adtech industry's distributed surveillance machine, for profiling and targeting.
However, thousand of shady companies in the data supply chain have access, and many data brokers also sell the raw data including all the identifiers, which are a crucial KEY PART of the machine.