Yes but that doesn't instantly mean that he has mental health problems. Players who liked to go out too much or were prone to making stupid decisions both on and off the field get described as being weak mentally or have a poor mentality. The only things I've seen in articles are that Shaw isn't disciplined enough to keep himself fit, no mention of mental health problems. I'm not saying you are lying or that he hasn't got them just that it hasn't been reported anywhere that I have seen.
If Shaw does have certain issues, it may be because all parties concerned may want to keep things private rather than having the issues blasted out of all proportion. That's my take.
PS: I thought I read somewhere that Shaw feels physically fitter than ever before. I feel a January loan coming on, Someone like Villa if they are interested.