The Board of Immigration Appeals has determined that “[a] respondent’s or qualifying relative’s testimony about a medical or mental health condition will generally be insufficient to establish exceptional and extremely unusual hardship where expert testimony, reports, or medical evidence exist and could reasonably have been produced.” Thus, the testimony of the applicant’s teenage son about his suicidal ideations was deemed insufficient to demonstrate the required hardship.
The full text of Matter of Pelagio Mendoza can be found here: https://www.justice.gov/eoir/media/1434771/dl?inline