Behavioural effects of hashish in mice in comparison with other psychoactive drugs.

1. The behavioural effects of hashish extract (10 mg delta 9-THC/kg) were compared to those of morphine (20 mg/kg), diazepam (10 mg/kg), imipramine (10/kg), amphetamine (10 mg/kg) and chlorpromazine (10 mg/kg) by testing male mice in a resident-intruder situation. 2. The drugs were given either to the resident or to the intruder male. 3. Hashish extract similar to diazepam and chlorpromazine reduced social activities in resident and intruder males. 4. Intruder males treated with hashish or diazepam were more frequently attacked and submission and light was increased. 5. Amphetamine and morphine stimulated locomotion and non-social activities but impaired social behaviour especially in residents. 6. Imipramine increased aggressive behaviour in resident and intruder males.