This work aimed at gathering the most recent work in craving to explore the phenomenon of craving in drug dependency and assessment of craving including etiological, diagnostic, psychometric and prognostic aspects. This study has been divided into 2 parts, theoretical & practical parts. In the practical part we selected 90 subjects (30 drug dependent, 30 volunteered smokers & 30 ex-addicts) and we applied psychometric tests and analyzed the data.