Hi there! My name is XXXXX XXXXX X am a licensed psychotherapist in the USA... I did some searching, and have found what seems to be a very reputable program designed for adolescents:
From the description, this program is 4 weeks in the evening, and designed specifically for the issues that your son seems to be presenting with. There are psychiatrists on staff, and well as many other services available there. Hopefully, it is close to where you will be staying?
Also, here is a list of other practices from which you can research to find the optimal practice: http://www.aussieweb.com.au/directory/psychiatrists/wa/perth/
Cygnet Clinic has a couple of male psychologists who specialize in adolescents: http://www.cygnetclinic.com.au/About_Us.html
From my research, I would suggest that you first reach out and contact the Marian Centre, as it seems to be the highest quality of full-service facilities on the list. I hope you found this helpful, and I wish you all the very best in your continuing journey to helping your son! All my very best to you, and please let me know if you need further information or assistance! Thank you for using the site today!