Posted 30 September 2009 - 04:12 AM
The jury is still out on amphetamine neurotoxicity at therapeutic doses. Consumption of moderate amounts of caffeinated beverages (e.g. coffee, tea) are associated with reduced risk of some diseases in epidemiological studies (grain of salt), and there is a wealth of literature on the subject. I wouldn't recommend 800 mg of caffeine to anyone. Yikes.
Caffeine is pretty crappy for ADD-I IME. Some have good luck with green tea, as the caffeine is modulated by the theanine. Comparing amphetamine to caffeine is kind of an apples and oranges situation... amphetamine is such a more powerful and cleaner drug, it's in a league of it's own (the same can be said of modafinil).
Both substances have acute antidepressant effects, but using them to treat depression could increase risk of abuse, particularly in the case of amphetamine. Chronic low dose amphetamine use results in tolerance to the euphoria inducement of the drug, but not to the attention boost. If you're trying to make yourself feel better, you might find yourself escalating your dose and ruining your sleep/health/brain.
Some people with ADD get an anxiolytic effect from amphetamine, and for some it is anxiogenic. Caffeine, on the other hand, is more likely to cause anxiety in pharmacological doses IMO, while megadosing also retards beneficial effects on working memory and basically turns you into a crackhead.
Also, most people who have tried both prefer dexedrine (dextroamphetamine) over adderall (mixed d and l isomers). I find dexedrine to provide slightly better drive and focus with significantly fewer side effects (tics, jitters, racing heart, etc).
Please be careful, keep your doses low, and only ingest prescription stimulants under the supervision of a medical professional. /end preaching