Regarding the association between internalizing problem behaviour and cannabis use in adolescents and young adults, several studies were published in recent time. Using cross-sectional data from adolescent and young adult cannabis users of the project "CAN Stop" (n = 239; age 14-23), associations between internalizing problem behaviour, cannabis effects expectancies, number of psychosocial problems and severity of dependence were analysed with an age- and gender-sensitive perspective. By describing young cannabis users, we seek to deepen the understanding of the association between cannabis use and internalizing problem behaviour. Cannabis users with normal-range YSR/YASR-profiles, internalizing problem behaviour, externalizing problem behaviour or combined problems differ significantly regarding their age of first cannabis use, age of regular cannabis use and number of both cannabis and alcohol use days. Regarding cannabis effects expectancies, cannabis users with externalizing problem behaviour show a broader variation of positive expectancies. Internalizing problems were associated with impairing and sedating effects expectancies.
