This year's World Mental Health Day theme is psychological first aid, I did nails in 2014 for this cause as well which you can find here. While a plaster isn't going to cut it for psychological first aid I think it is the general symbol for first aid.
Barry M - Lychee
Barry M - Key Lime
Leighton Denny - Sink into Mink
Stamping Polished: Barry M - Key Lime
Stamping Plate: Bundle Monster 321