Thanks for your question. I'm happy to try to help. I can appreciate your desire to find an appropriate holistic or alternative remedy for your son, especially as it seems that traditional methods are not providing much benefit and/or he's not responding well to them.
An alternative treatment such as Reiki, acupuncture (which is used pretty extensively in most traditional substance abuse
programs) or another energy-based medicine might be a good place to start. You could also consider a consultation with a Traditional Chinese Medicine practitioner (who also performs acupunture, Chinese massage and prescribes herbal remedies): http://www.atcm.co.uk/
However, it sounds like there are a number of potential issues going on with your son right now, and the most worrisome to me (and to you, from what you've said in your message) is the paranoia and the binge drinking.
My initial recommendation would be to have an evaluation at a substance abuse treatment center, because they might be able to address both issues simultaneously, especially if the drinking is instigating the feelings of paranoia. They'll have a psychiatrist on staff as well, although I do also hear your concerns about him simply being prescribed medication without the underlying issues being addressed. You might be interested in reading the following article, which explains some of the research regarding acupuncture and substance abuse (alcohol included): http://www.acupuncture.org.uk/index.php?option=com_k2&view=item&id=384:substance-abuse-and-acupuncture-the-evidence-for-effectiveness&Itemid=105
If you're interested in finding an acupuncturist who can help with the alcohol problem, you can look here as a starting point: http://www.nadauk.com/
Another alternative option to consider is biofeedback.
You can read more about this treatment here: http://www.altmd.com/Articles/Biofeedback-Therapy-for-Alcoholism-and-Substance-A
It's a very effective method for treating alcohol addiction as well as a number of psychological disorders. If you're not already familiar with biofeedback, it's essentially a method that teaches the patient ways of handling and managing their brain's electrical activity through the use of special machines, breathwork and mindfulness techniques.
You can find a qualified practitioner in the UK here: http://www.naturaltherapypages.co.uk/energetic_medicine/Bio_Feedback or here: http://www.worldwidehealthcenter.net/directory-6.html
It sounds like a combination of one of these treatments (acupuncture, biofeedback, or possibly even massage therapy, which has been found to be effective at managing alcohol withdrawal
symptoms - it's something to consider) combined with a more conventional approach (CBT is a good place to start, but he has to be willing to commit himself to the treatment process. I'd also consider a group modality such as AA) would be beneficial, if he doesn't want to attend a conventional substance abuse treatment program.
However, I'd like to provide you with more information about where you can seek a more holistic-minded substance abuse program, just as an example (although there are many similiar programs out there as well): http://www.abbeycarefoundation.com/treatment-programme/holistic-alternative-therapy/
A program like this, which incorporates alternative treatments, may be his best bet at this point, although you'll have to discuss it with him to see what he's willing to do. I think he would benefit from a structured programme since he is having so much difficulty engaging in a regular routine right now.
I hope that helps. Please let me know if you need additional assistance. Best wishes.