From what I understand, most people get involved with the psychic thing because they are lonely and depressed, falling prey to hearing a friendly voice.
For someone that is very depressed, what happens after that two weeks is up?
I'd look more into the causes of your son's unhappiness instead of looking for something to blame it on.
As with most things discussed here, professional counseling is probably a good route to explore.
Reading this thread I would be be more inclined to agree with the above post. I have a son who is going through a rough time at the moment except he isn't suicidal. But the withdrawl from society and life etc is obvious. He writes notes to himself and if he feels he's going to forget something he will get a marker pen and write the note to himself on the side of the car, a van, he owns so when he gets into the driver's side he sees it as a reminder. Then he covers the note up later with black gaff tape because there is no way it can be rubbed off the paintwork.
It's very bizzare eccentric behaviour and he too has been known to go to a psychic and read stuff about finding nirvana etc.... But after a 'breakdown' in trying to cope with life without asking for help, he is now on Disability Allowance being diagnosed with Asperger's Syndrome, which is a high functiong forum of Austism where the intellect, IQ, is normal or above normal but they have problems understanding the way society and relationships and stuff like that works. In his case too, he has General Anxiety Disorder where his Depression level is moderate, but his Stress level is severe and his Anxiety level is extremely severe.
It's also deemed that he is not on drugs, which admittedly at some stage I thought he was though he never seemed to be spending big or running out of the money he has. He lives on very little because his basic needs are little. He hardly drinks and in his case he is a vegetarian, but one who doesn't fully understand the need for a vegetarian to make sure his protein intake is balanced.
In no way am I ever insinuating that your son is like mine... I'm simply giving you the idea that in instances like this it is better to look for a cause than to blame a psychic who may not be a big part of his life anyway... However, the psychic could be merely a person he went to to seek 'help'. You often find troubled people will do stuff like that... go to psychics who supposedly 'predict' the future..... naturally hoping that the news the pyschic will bring them about themselves is positive. Like a way out when they themselves feel trapped and don't know which way to turn. It's also secretive in that you don't need to go to a doctor, and your family and friends need ever know you have a 'problem' because it's not 'official' type help...
I wouldn't call going to a psychic cultish, other than some people do go to psychics regularly and use them as a way to direct their life and yeah, that's a pretty crap way to live. What psychics do is really offer people 'psychological' unrealistic type props and it isn't such a great thing to do to yourself. Actually, it can be an outright dangerous thing to reply on in my opinion because they are not trained to perceive potential problem ridden 'clients'. To me, it's more akin to seeking the wrong person for help and advice when a good psychologist or another support type councilor or even talking to family and friends would be a much better option.
Just a few thoughts from personal experiences from having a 'troubled'... a lost soul son myself.