INTRODUCTION: Psychoactive substances affect different mental processes such as perception, consciousness, cognition or mood and emotions, and their use is not necessarily identified with the development of addiction, but unwanted consequences are associated with "abuse" or "excessive use". Psychoactive substances are usually divided into stimulants and depressants of the central nervous system, opiates, and hallucinogens. OBJECTIVE: The aim of this research was to determine whether there are statistically significant differences in negative emotions and different types of aggressiveness in persons prone to abuse of psychoactive substances compared to the control group. The specific goal of the research was to determine the connection between negative emotions and aggressiveness in people with a tendency to abuse psychoactive substances. METHODS: The research was conducted at the Insula County Special Hospital, and the subjects were divided into two groups: a criterion group - people being treated for abuse or addiction to psychoactive substances (N= 44) and a control group (N=55). Data for the research were collected through 3 questionnaires: sociodemographic data questionnaire, DASS-21 and BPAQ. Statistical data processing compared the results of the questionnaire in both groups, with the aim of assessing stress, anxiety, depression and aggressiveness and their connection with the abuse of psychoactive substances. RESULTS: The total average score of the DASS-21 questionnaire was 30.41 in subjects with a tendency to abuse psychoactive substances, and 9.49 in the control group (t = 8.79; df = 93; p < 0.05) conclude that people taking psychoactive substances have significantly more negative symptoms than the control group. The average results of the aggressiveness questionnaire, which assesses four types of aggressiveness in the subscales of physical aggressiveness, verbal aggressiveness, anger and hostility, is statistically significantly higher in subjects who have a tendency to abuse psychoactive substances (t = 10.32; df = 93; p < 0.05). CONCLUSION: Abuse of psychoactive substances is associated with negative emotions such as stress, anxiety, depression, and aggressive behavior.