Hah, the depressive part is just not as obvious as the pleasurable one, so you need some introspection to figure out the connection between low mood and deprivation from the drug and be able to admit it. This is how all addictive drugs work, no matter if we're speaking of nicotine, methedrone, heroin, or something else. They give you a temporary pleasure which seems very tempting, but it's not given to you for free, it's rather a credit which you have to pay back soon.
I have enough smokers around me, and I have an opportunity to see how miserably they look when they are deprived from the possibility to smoke due to various temporary circumstances. The only thought that comes to mind when seeing their withdrawal symptoms is "fuck this so called pleasure".
I'll be dead within a month. Why should I deny myself any pleasure I can get in this time.
I presume, your first payback moments may come much sooner than a month, but you should know better.