Is it true drugs like Adderrall and Provigil do not leave you with a sleep deficit?

We put this to Charlotte Housden:

Charlotte - What these drugs seem to do is they seem to counteract the effects of excessive day time sleepiness. So when you're feeling sleepy during the day, what they do is they allow more stimulation of the prefrontal cortex, making you feel more awake. However, sleep has been shown to be essential for processes such as memory reconsolidation, so that's learning things and processing the things that you've encountered during the day. So although you may not feel as sleepy when you take stimulants such as Adderall and Provigil, actually, you probably should try and catch up on your sleep. That's not the answer. You shouldn't stay awake all the time and just take drugs.