Just be careful when you're using these drugs. Tolerance may likely develop even with a dosage under prescription. While it improves your overall concentration, the stimulant may impair your inherent ability to think critically. It may impair your judgement, and may cause hallucination when taken for long-period of time (more than 8 weeks).
I've been taking adderall everyday for about 6 months. I actually started with 10mg couple of years ago on and off. The feeling of well-being I got from Adderall was indescribable and made me do extremely well in school. This is on a 20-30 mg a day pill. Soon, the feeling got weaker and wore off quicker, which made me have constant mood swings... so I knew I had to stop taking it upon graduate school. However, I somehow began taking it again to study for the MCAT, only I knew how addictive it was so I only took a normal constant dosage of 20 mg -30mg a day. Soon, I needed 30 mg to keep up "normal" life and then 40 mg, then 60mg. At that point (which is where I am now) no amount of Adderall can help me really "focus". I need to take 40 mg a day just to get through Kaplan prep class and 60mg to do additional homework assignment for the MCAT. I do not get that same feeling that Adderall gives anymore. You could say I'm addicted to it; however, I'm not the only one.
Even if you take adderall only as prescribed, it can be dangerous. My psychiatrist put me on this drug 20mg-3 x/ day.
I still frequently hear voices even though I'm not on adderall. When I try to read verbal passage, sometimes I can't concentrate because I keep hearing this inner voice from back of my head. I lost so much weight because of this drug. Now it's hard to taper this drug off abruptly because of withdrawal effect such as extreme fatigue, depression...etc. My life is on crank.
For this reason, I'm even deciding to put off taking April MCAT for now and take it in August. I don't advise anyone to take this drug frequently.
I gotta take care of my health first before my brain get messed up permanantly and become a complete *****.