An RMIT University study has found a significant number of young people have been victims of drink spiking.

Psychologist Bridget McPherson and RMIT colleagues sampled more than 800 people aged between 18 and 35.

Ms McPherson said one quarter of participants reported being victims of drink spiking.

She will present the results tomorrow and on Friday at the annual Australian Psychological Society Conference in Brisbane.

She said revellers needed to be careful about supervising their drinks.

“Interestingly, the majority of incidents that participants reported had occurred in licensed venues. Typically, the spiking took place when they left their drink unattended or accepted a drink without seeing how it was prepared.

“Despite such experiences, nearly 85 per cent of victims did not report the incident to authorities.”

Drink spiking could take the form of adding alcoholic shots or drugs to beverages, she said.

The RMIT researcher also uncovered some of the motivations behind drink spiking.

“Some of the perpetrators expressed the belief that deliberately causing intoxication in others was acceptable,” Ms McPherson said.

“Many participants people who spiked someone else’s drink were motivated by the belief they’d increase their chance of engaging in sexual activity,” she said.

Drink-spikers said it was “easier to approach people for sex if they're drunk or drug-affected”. Others listed “fun” as a motivation for drink spiking.