Drug-assisted thought? Not quite. Tom Brown shared with us his thought regarding picking speed. There is some very useful advice contained herein. Reprinted by permission from a post in rec.music.makers.guitar.jazz.
For the record, I pick 16th notes at about 120bpm.
You should probably try to get that up to at least 150 or 160. Start on one note, then move on to simple, easy to finger licks that lie one only one or two strings. Use a metronome. Try to stay relaxed.
However, picking speed does not equal the ability to improvise at fast tempos. They are two separate but somewhat related challenges. Here is a post on the topic that I wrote a few years ago and post occasionally:
I won't pose as an expert in fast bebop. I've been scuffling at this stuff for years. But I finally got fed up with sucking on fast tunes and decided a couple years ago to get fast bebop together. The good news is that it's doable even for someone like me who is fairly slow by nature. Although it's taking me a long time, I am finally starting to get there.
Picking speed does not equal the ability to improvise at fast tempos. They are two separate but somewhat related challenges
The usual line you hear is that to learn to play fast you should practice slow. I think this is wrong; at least, it is only half of what you should practice. The rationale behind it is that you should practice playing cleanly, and that if you go too fast you will just be practicing playing sloppy at fast tempos.
The problem with this advice is that getting the fingers moving is only one small part of burning. The main part is being able to think that fast. The only way to learn to think fast is to practice playing fast tunes. You can start by soloing with half notes or quarter notes, and when this gets comfortable, you'll find yourself throwing in a few short eighth note runs every now and then.
Another approach is to practice material at the macro level--that is, learn some bebop licks that you can work up to speed (starting slow and focusing on accuracy). Most guys you hear soloing fast are playing preconceived stuff. It's easy to put down, but that is how the music works. It's also a good way to get started at fast tempo bop. Once those tempos become more comfortable, you'll find yourself thinking ahead a bit further, and your soloing will become less mechanical, less lick oriented, and more fluid. But you can start by practicing some licks that you can get up to speed, and throw them in when it seems appropriate.
You will probably find that harmonic generalizing becomes very helpful at fast tempos. In other words, you will consider a ii-V-I cadence as one harmony, and perhaps traverse it more horizontally and less vertically than you might at a slower tempo.
The other thing to consider is that not everything you can play can be played fast, either because it is physically forbidding at those tempos, or because it just doesn't sound good speeded up. Then there are ideas that work at fast tempos but sound dumb slowed down. This is another reason why one needs to practice starting at fast tempos rather than working up to them--how else can you develop ideas that sound good fast and are playable at those tempos?
Since I play guitar, and many bebop licks are virtually unplayable on guitar above 280 or so, this has been important for me. I have had to develop a whole new vocabulary that I can execute at fast tempos. For example: I get into rhythmic variations on one note; taking a short phrase and repeating it at different relations to the pulse; "perpetual motion" repetitive moves that build tension up to the point I am ready to move into a more melodic groove; looking for simple riffs that can develop into call-and-response choruses; interacting with the bass and drum groove focusing mainly on rhythm; quoting other tunes at half-time relative to the rhythm section pulse; and so on. There are all sorts of things that jazz does at fast tempos differently than it does at slow tempos, and you only learn them by practicing that way.
Finally, now when I sing to myself in the shower or while driving, I sing fast bop tunes. I think this kind of mental practice away from the instrument is just as crucial as actual instrument practice, because it gets your mind thinking up ideas at rapid tempos--and believe me, learning to think fast is a *lot* more challenging than simply learning to play fast. My fingers are usually way ahead of my mind.