Table schema:
CREATE TABLE table_name_55 (psychological_dependence INTEGER, physical_dependence VARCHAR, pleasure VARCHAR, drug VARCHAR)

Question: What is the highest Psychological Dependence, when Pleasure is less than 2.3, when Drug is "Cannabis", and when Physical Dependence is less than 0.8?
SQL: SELECT MAX(psychological_dependence) FROM table_name_55 WHERE pleasure < 2.3 AND drug = "cannabis" AND physical_dependence < 0.8