Lotus Flower

In The Lightning Thief (film), the staff of the Lotus Hotel and Casino keep people in the hotel by using a lotus flower cookie that numbs the senses.

Effects
During the movie Annabeth, Percy Jackson and Grover eat the lotus flower, as served by attractive waitresses. The flower dulls the senses and makes the eater not want to leave the hotel. It must be eaten every once in a while to renew the spell. When the trio of heroes first eat the flower, it makes them act like they're intoxicated.

It is said by the trio that it is the most delicious thing they had ever eaten. This is likely what caused them to become briefly addicted to it: causing them to eat it and the drug to affect them for a time. It only appears in the movie.