INTRODUCTION: The use of psychoactive substances has become an increasing social and medical problem. The problem is both their availability and variable composition together with hard to predict health effects.

MATERIAL AND METHODS: The materials used in the publication were obtained by searching the PubMed database for the following keywords: „novel psychoactive substances”, „new psychoactive substances”, „NPS”, „legal highs”, „smart drugs”, „bath salts”, „psychoactive drugs” „designer drugs”, „internet drugs”, „synthetic catinones”, „synthetic cannabinoids”, „novel psychoactive substances AND psychosis”, „new psychoactive substances AND psychosis”, „legal highs AND psychosis”, „legal highs AND psychosis”. Materials published until the January 2017 were taken for the analysis.

RESULTS: The article describes classification of the new psychoactive substances based on type of chemicals. There were described their working mechanisms and related psychophysical effects. Present research and case studies were also presented. In addition to the symptoms of the nervous system or cardiovascular system, a number of symptoms of psychiatric disorders such as hallucinations, delusions, agitation, aggressive behavior, sleep and wakefulness disorders, anxiety and affective disorders have been described. Frequency and severity of symptoms were often dependent on the type of substance and the dose taken. Some of the cases described required hospitalization.

CONCLUSIONS: Issues related to the novel psychoactive substances are related to the availability of these substances, the amount of the substances belonging to this group, the ease of synthesizing new agents and to the limited possibilities of labeling these substances. The use of this group of substances can cause various symptoms of psychiatric disorders, not specific for chemical substance.