Well, I'm only addressing marijuana here. Yeah, I mean MJ is just another tool and as I said one can mis-use it, but when one uses it wisely it rewards the user with insight worthy of improving ones life. So while in some cases MJ may not be conducive to the work one must do, it can still be a life-enhancing tool. I know Marijuana to be a focusing agent that can enable the user to sustain high levels of concentration when the setting, both mental and physical is right.
My theory on MJ induced paranoia is that, the condition has more to do with the criminality of MJ than anything inherent in MJ, itself. The novice user experiences a new and different sense of reality which destabilizes the ego and creates social vulnerabilities. Being criminalized at this point for wanting to explore alternate forms of reality is recognized by the user as so absurd and ungrounded that one must question the general judgement of those who condemn MJ users to criminal status. I think if it were legal and socially accepted and you could do it without fear of arrest most of the paranoia would disappear.
I also think you may have been lulled into a false sense of security, somehow, concerning the de-facto legal status of MJ. I know people who have been denied work because they couldn't pass the piss test. They were all set to be hired otherwise, but because the cat smoked pot about once, 2wice a week he was kept unemployed. Another good friend of mine had his 6 small children taken from him by the county(backed by state and Fed) and put into foster care for 6 months because his wife was on probation and they found MJ in the home. The crime committed by the county/ state/ Fed against my friend's family is way unjust. Also penalties against growers can be heavy depending on where you live.
as far as the other drugs go...i was adressing the poster that said they should test people to see if they are at least smoking weed.
Your theory on MJ paranoia is partially right. most people only get paranoid because of the illegality. but, MJ itself can cause nonspecific panic/anxiety symtoms if it is overused. Take my case for example: I was able to up untill a few months ago to smoke unlimited amounts of the best weed there is. i could burn through an 1/8th of sour d or trainwreck in a night easily, i was going through around an ounce a week (i know growers, i get good weed cheap...like two grand a pound for A+ shit). Then, one day i ate a brownie. nothing new, eaten brownies before. but this time, I started freaking out that i was going to die. my heart was beating like crazy and sloshing around. felt like i weighed a thousand pounds. After the trip was over i stayed in a panic state for months. i coulnt smoke weed at all for a while because just the littlest hit would send me into a panic attack. that lasted a few months. i had to go on some hardcore psych drugs just to function on a day to day basis. I'm fine now, but if i smoke too much at one time i can still get that way and need to pop a valium or have some wine to calm myself down. no more brownies or two gram joints for me!
Oftentimes it's the MJ's tendency to cause anxiety which manifests itself in paranoia. when theres no outward cause of the paranoia (e.g police) that anxiety gets focused other places, like inwards, and transforms from paranoia into panic/anxiety attacks. ever seen anyone "bug out" on weed? you know what i'm talking about. You can be all macho about it and say "oh, i can handle it, i've tripped on acid/shrooms/dmt X number of times and that was a piece of cake"....smoke or eat too much too often and the weed will put you in your humble place one rainy day.
There are times and places where MJ can get you in trouble. if you're smart, you never will. take for example new york. they have a system set up where (off the books) you can get caught with weed an unlimited number of times and as long as it's under an ounce, you have an otherwise spotless record and you get a lawyer, you will never ever have to go to jail or pay a fine or have a record for it. Cops dont care, on the street they make you just put it out or put it away (only if your white; if your black, hispanic or look thug-ish you go to jail lol) If you're caught smoking around your kids it's a different story. If you do end up getting a citation (a summons) it goes like this: if you have a lawyer, the court will not waste it's time and will dismiss the case on the spot. as long as you dont keet getting the same judge (you probably wont), your cases will continue to get dismissed. there is an unofficial (a courtroom etiquette so to speak) law in NY that essentially states that people with clean records deserve a pass their first time getting caught. If you get different judges each time, they wont know you've been caught a few times because it's not on your record. at worst, you may get an ACD (adjournment in contemplation of dismissal) which means if you stay out of trouble for six months your case is dismissed. it's kinda hard to get caught here though: you have to really be obnoxious and smoke on the street standing on one place blowing smoke at a cop to get in trouble, most new yorkers dont care and mind their own bussiness, and we have delivery services so your weed never leaves your house. even if your neighbors call in a complaint about the smell of weed the NYPD tells them to mind their own business and never show up. There is really no way to get caught in NYC with weed in the first place unless your stupid about it. You have to bassically walk around with a bag a weed open in your hand, or joint sticking out of your mouth, or drive around in a smokemobile all day to get caught.
In california, it's even easier. pay a hundred dollars for an medical card and the police cant touch you. or in massachusets, you just give the cops a fake name when there writing you up a ticket and your scott free...that is if your just not up for the 100 dollar fine. in maine they just dont give a shit. instead of busting growers outdoors they just cut the plants down then leave a message on the growers door: "give us a call, if you'd like", and they keep a blind eye to kids cruising around smoking weed on their lunch hour in high school - they have oxycontin to worry about.