Do sexual expectancies and inhibitions predict high-risk sexual behaviours? Evidence from a cross-sectional survey among young psychoactive substance users in informal settlements in Kampala, Uganda

BACKGROUND: Psychoactive substance use is a public health challenge among young people in informal settlements. Though rarely examined, psychoactive substance use is linked to sexual expectancies and inhibitions, and consequently high-risk sexual behaviours. This study examined the association between sexual expectancies and inhibitions, and high-risk sexual behaviours among young psychoactive substance users (PSUs) in informal settlements in Kampala, Uganda. METHODS: This cross-sectional study recruited 744 young PSUs from informal settlements in Kampala. Respondent driven sampling was used to recruit respondents. A ‘modified’ Poisson regression model was used for inferential statistics. Data were analysed using the Stata 14 software. RESULTS: Of the 744 study participants, 45.6% believed that psychoactive substance use improves sexual performance; 43.3% believed that psychoactive substances make sex more pleasurable, and 53.3% believed that psychoactive substances give courage or confidence to approach a partner for sex. The belief that psychoactive substance use improves sexual performance (PR 1.14, 95% CI: 1.01–1.30), increases the likelihood of engaging in sex (PR 1.20, 95% CI: 1.04–1.40) or gives courage or confidence to approach a sexual partner (PR 1.21, 95% CI: 1.05–1.39) were associated with having sex while under the influence of psychoactive substances. The belief that a psychoactive substance user under the influence of psychoactive substances is more likely to engage in sex (PR 1.48, 95% CI: 1.15–1.90), and likely to find it difficult to refuse sex (PR 1.28, 95% CI: 1.06–1.55) were positively associated with engaging in multiple sexual partnerships. The belief that one easily forgets to use a condom when under the influence of psychoactive substances was positively associated with inconsistent condom use (PR 1.26, 95% CI: 1.09–1.45). CONCLUSION: Psychoactive substance use expectancies associated with high-risk sexual behaviours included the belief that psychoactive substances improve sexual performance and improve confidence in approaching a sexual partner. Psychoactive substance use inhibitions associated with high-risk sexual behaviours included an increased likelihood of engaging in sexual intercourse, difficulties in refusing to engage in sexual intercourse, and forgetting to use condoms while intoxicated. Interventions targeting a reduction in high-risk sexual behaviour should integrate the impact of psychoactive substance use on sexual behaviour. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-11536-8.