Hi there ~
Such problems during childhood are common and usually resolve when children hit puberty
. Nevertheless, the fact that you have noticed it is of concern and to relieve the stress
that your friend I would advice you to take him to a psychiatrist
to get his problems resolved. There are many conditions that present this way and it could only be hormonal
for all that. If there is emotional and psychological issues involved, it would need the expert opinion of a psychiatrist. I hope this helps.
Take care and have a lovely day !