Whatever you may think the official definition is, psychiatrists tend to use the term in only one of two ways: either incorrectly, as “almost schizophrenic, but still can hold a job and doesn’t hallucinate;” or as a pejorative label describing one who believes in all sorts of fantastical things– aliens, esp, conspiracies, 911 was done by Bush, etc– but believes them in a logical way (e.g. not “aliens came to my house and we played cards.”)
If it’s the latter, then the psychiatrist isn’t making a diagnosis, he’s describing his observations about a “patient’s” character.
Can this kind of schizotypal be “treated” with therapy? The person has to decide why he’s so invested in these ideas (e.g. believing in conspiracies is a way of reassuring oneself that, after all, there is someone in charge, and that none of this is haphazard. It also means of there is some gigantic catastrophe, someone will be able to take care of us; and also means that any failures in your life aren’t fully your fault, because you’re not a member of TPTB, so you’re being kept down. Etc.)
What about when the psychiatrist means it as “almost schizophrenic?” It means you need a new psychiatrist. (Similarly, antisocial is wrongly used to mean shy.) Almost schizophrenic– illogical, prone to delusions/hallucinations is a different, more severe matter, that probably will need meds, depending on how old the guy is. <30 means it could get worse; >30 means this is probably as bad as it will ever get.
Going out on a limb here: is marijuana involved? Clinicians like to think that drugs exacerbate pre-existing conditions, but how can anyone tell? Clinicians like diagnoses: crack didn’t cause depression, you were depressed and used crack. Either way, no amount of therapy or Zyprexa can counteract the effects of daily weed.
So the clinician labeled him schizotypal, it suggests to me that the symptoms were present but vague… and that he smoked a lot of marijuana. Start with that.