However, everyone reacts differently to the combination. Some find that consuming CBD with coffee helps take the edge off a strong caffeine dose, while boosting it with THC can increase alertness and energy. A study suggests that the combination can improve cognitive performance, offering better concentration while the user also enjoys the medicinal benefits of cannabis. In another study, researchers found that both marijuana and caffeine lead to a spike in dopamine levels through various mechanisms. The findings suggest that when these are taken at the same time, this dopamine increase could be responsible for the boost of happy feelings and euphoria.