Start with a calm, private check-in and listen without rushing to fix things....

https://wiki-site.win/index.php/How_Do_I_Bring_Up_Mental_Health_Concerns_Without_Sounding_Accusing%3F

Start with a calm, private check-in and listen without rushing to fix things. Ask what kind of help would feel useful, such as finding a counselor, making a call, or sharing a meal