Psychoactive substances alter mood, cognition and behaviour. Depending on the substance being used, a person’s anger can be stimulated and exacerbated or moderated and suppressed. Aggressive or violent behaviour may be more likely for some young people when they are unable to obtain substances, are hung over or coming down or when they are in withdrawal.

For detailed information on particular substances in relation to pharmacology, the effects of intoxication and withdrawal syndromes see Drugs & their effects.

For detailed information on responding appropriately to intoxicated clients see Responding to intoxication and overdose.