* INABILITY AND UNWILLINGNESS TO ACCEPT REALITY. Hence the escape into the dream world of gambling. 

* EMOTIONAL INSECURITY. A compulsive gambler finds he or she is emotionally comfortable only when "in action". It is not uncommon to hear a Gamblers Anonymous member say: "The only place I really felt like I belonged was sitting at the poker table. There I felt secure and comfortable. No great demands were made upon me. I knew I was destroying myself, yet at the same time, I had a certain sense of security." 

* IMMATURITY. A desire to have all the good things in life without any great effort on their part seems to be the common character pattern of problem gamblers. Many Gamblers Anonymous members accept the fact that they were unwilling to grow up. Subconsciously they felt they could avoid mature responsibility by wagering on the spin of a wheel or the turn of a card, and so the struggle to escape responsibility finally became a subconscious obsession.

Also, a compulsive gambler seems to have a strong inner urge to be a 'big shot' and needs to have a feeling of being all powerful. The compulsive gambler is willing to do anything (often of an antisocial nature) to maintain the image he or she wants others to see.

Then too, there is a theory that compulsive gamblers subconsciously want to lose to punish themselves. There is much evidence to support this theory. 

Source : http://www.gamblersanonymous.org/ga/content/questions-answers-about-gamblers-anonymous