The chapter presents a multidimensional model where alcohol and drug use-misuse is considered as a multifactorial bio-psychosocial process. The multidimensional model describes the complexity of factors that contribute to alcohol and drug usemisuse and how this makes its study very challenging. The theoretical model considers many dimensions related to different intrapersonal and extra-personal factors affecting alcohol- and drug use-misuse.

The intrapersonal influences include processes contributing to personal differences in alcohol and drug use. The focus is especially on neurobiological processes, personality, affective states, including, cognitive motivation or expectancies as behavioral motivators. Extra-personal influences consider demographics, environmental, social and sociocultural factors.