It should be common knowledge by now, as the problem has been documented for decades and discussed here many times.[1][2][3][4]

As far as an actual citation: "Studies from Kjølseth et al. (2009), and our own findings (Szücs et al., 2020), suggest that older adults who die by suicide or have late-onset (mostly high-medical lethality) suicide attempts are often high-functioning throughout most of their life, and characterized as controlling, rigid, high-achievers, also high on orderliness (a conscientiousness subcomponent)."[5]

[1]https://www.nytimes.com/1996/05/01/us/higher-suicide-risk-fo... [2]https://www.deseret.com/1988/9/13/18777827/30-percent-of-tee... [3]https://www.depts.ttu.edu/research/scholarly-messenger/2016/... [4]https://everymindatwork.com/high-achievers-and-mental-health... [5]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655527/