I really think there is a connection. Before I used any drugs (I'm mostly into psychedelics and ethnobotanicals) I only had lucid dreams (no control, though) a few times a year. After I started using magic mushrooms and some powerful smart drugs, I started to have dreams several times a week. I have never had control over my lucid dreams, though. That's why I'm pretty eager to try out some ethnobotanicals that should allow one to gain control over a lucid dream.    Examples of these herbs are "Calea zacatechichi" (dream herb), "Silene capensis" (african dream root) and "Entada rheedii" (african dream herb). These are legal easily obtainable herbs.