Both recent psychiatric classifi cation systems include pathological gambling into similar diagnostic categories: ICD – 10 into the group of Habit and Impulsive Disorders, DSM-IV among Impulse Control Disorders not Elsewhere Classifi ed. However many features of pathological gambling (e.g. formulation of diagnostic criteria, characteristics of course and outcome and possibilities of prevention and treatment) are conspicuously similar to OC spectrum disorders and, on the other hand, to drug and alcohol addiction. The aim of our work was to evaluate the proportion of obsessive thoughts and compulsive behaviour in the group of patients with pathological gambling in comparison to patients with alcoholism and drug dependence. We compared the total scores of modifi cated Y-BOCS so as the subscores of obsessive thoughts and compulsive behaviour relevant to problem areas in all groups of patients. The results of our research did not show any statistical differences between total scores of modifi cated Y-BOCS, or in the subscores representing obsessive thoughts and compulsive behaviour of pathological gamblers in comparison to the group of alcoholics and, on the other hand, to the group of patients with drug dependence. It supports the opinion of close similarity of pathological gambling to psychoactive substance dependence. Obsessive and compulsive symptoms of pathological gambling could be also seen in the wider frame of the group similarity of dependencies and so called OC spectrum of mental disorders.

        Key words: pathological gambling, impulse control disorders, OC spectrum disorders, substance dependence.