I'd not say loneliness and dissatisfaction are the cause of gambling addiction, but surely they would promote it. When there's no one to talk to you or ask where are your money going or care for you, you'll be gambling irresponsibly. If there's some one you love wants you to spend your money on better things than gambling, you'll at least feel guilty Everytime you gamble.
If we don't have responsibility for our life, then we cannot take care of what we have, and we might lose everything in life. The loneliness and dissatisfaction can attract someone who does not care about other people, and if he goes to gambling, then he can be an addiction because he will not think other people around him. He will focus on gambling, no matter if he wins or loses.