[ES] La Escala GENCAT aparece como el ?nico instrumento que permite evaluar la calidad de vida individual de personas con drogodependencias desde una perspectiva diferente a la de calidad de vida relacionada con la salud (CVRS). Dado que las propiedades psicom?tricas de la mencionada escala s?lo se han estudiado para la muestra general de usuarios de servicios sociales, este estudio tiene como objetivo analizar su fiabilidad y validez en un grupo espec?fico de personas con drogodependencias. Para ello, se aplic? a 75 drogodependientes usuarios de servicios sociales en Catalu?a. Los datos obtenidos permiten concluir que la escala, para este colectivo, presenta una adecuada consistencia interna (que supera en algunos casos la obtenida para la muestra general) seg?n la Teor?a Cl?sica de los Tests. Adem?s, se observ? que el ajuste medio de los ?tems al modelo y la fiabilidad promedio de las estimaciones de los ?tems fueron altos seg?n el modelo de Rasch, aunque los ?ndices de fiabilidad de las personas resultaron m?s moderados en la mayor?a de las subescalas y deficiente en el caso de la dimensi?n bienestar f?sico. Se concluye que, aunque la escala es v?lida y fiable en t?rminos generales, es aconsejable una revisi?n de la dimensi?n mencionada. [EN] The GENCAT Scale is the only tool used in the social services context that allows assessing individual quality of life of people with drug dependences and with a different framework from health related quality of life (HRQOL). Since psychometric properties of the scale have been only studied for the general sample composed of social service recipients, the goal of this study is to analyze its reliability and validity for the specific group composed of drug addicts. To achieve that goal, the scale was administered to 75 drug dependent people receiving support from social services in Catalonia. The obtained data allows us to conclude that the GENCAT Scale shows an appropriate internal consistency (better than the one obtained from the general sample in some cases) with the Classical Test Theory. Moreover, results showed that model fits and item separation reliability was high. However, person separation reliability was lower and deficient for physical wellbeing subscale. In conclusion, the scale is valid and reliable in general terms, but a revision of the mentioned domain is suggested. [EN]The GENCAT Scale is the only tool used in the social services context that allows assessing individual quality of life of people with drug dependences and with a different framework from health related quality of life (HRQOL). Since psychometric properties of the scale have been only studied for the general sample composed of social service recipients, the goal of this study is to analyze its reliability and validity for the specifi c group composed of drug addicts. To achieve that goal, the scale was administered to 75 drug dependent people receiving support from social services in Catalonia. The obtained data allows us to conclude that the GENCAT Scale shows an appropriate internal consistency (better than the one obtained from the general sample in some cases) with the Classical Test Theory. Moreover, results showed that model fi ts and item separation reliability was high. However, person separation reliability was lower and defi cient for physical wellbeing subscale. In conclusion, the scale is valid and reliable in general terms, but a revision of the mentioned domain is suggested.