Dude, I would be embarrassed to even mention this "study" in the company of professionals.
Excerpt:
49 people? And their ability to work and personal relationships suffered...hmmm. So, lets take a cancer patient and remove his meds for two weeks. I can guarantee that the cancer patient will become sicker, and his/her personal relationships will suffer. How about we just try this same "study" with water, air or food? Just LOL! Of course things will go downhill...but that is not "withdrawal". It is misleading to publish stuff like this. Wanna see withdrawal?
Heroin withdrawal:
Alcohol withdrawal:
Marijuana does not have PHYSICALLY addicting components. And I hate to tell you, but the scientific study of marijuana has been going on since long before you or I was born. The data does not lie. Nobody has died from marijuana use, at any level, even from highly purified concentrates of THC. I suggest looking at ACTUAL studies done by credible, reputable scientists who have used the scientific method and recorded empirical data on the subject. Here are 10 such studies conveniently in one place at the CMCR:
http://www.cmcr.ucsd.edu/index.php?option=com_content&view=category&id=41&Itemid=135
On that page with the 10 scientific studies done under strict conditions, more than half of them were conducted over 10 years with much larger sample sizes.
Its one thing to say that you don't like marijuana because it gives you headaches, and another thing entirely to try and claim that marijuana is addictive or that it impairs the minds of users. Perhaps you should just leave it at "I dont like it because it gives me headaches".
The science of marijuana is not in question here. Finding a two week "study" or two like the one you posted with a laughably tiny 49 person sample in Amsterdam, and trying to use it as reference material here is just...well, it is insignificant.