Strengths and limitations of the study
SUDs, comorbidity
This research is the first to be carried out in Spain with an objective clearly national in scope, and also reflecting the diversity of healthcare networks, with a sample of significant size. A descriptive approach and an inclusive definition of comorbidity were used. Given the above, it can be considered representative of people with diagnoses of SUD and on current OMDs in treatment throughout Spain. In short, the main strengths of this study are the size of the sample, the national scope, and the variety of treatment settings to avoid biases as far as possible, thereby ensuring an acceptable level of representativeness. In this way, specific aspects of women regarding prevalence and treatments could be studied. Although this study was carried out to prospect gender differences and changes, sadly the percentage of men is quite higher than that of women, but also since this is a clinical population and as have been mentioned accessing services for women is lower.A possible limitation of this study is that the inclusion of cases was not carried out in a uniform manner and could have resulted in bias in sample collection, especially given the fact that patients treated in the mental health network are less represented than those with addictions. This lower response in the mental health network to the surveys could reflect less awareness of the problem in this network. A bias in the patient sample may also result not only from the low profile of the mental health network but also from the heterogeneity of the care structures themselves throughout the country. Nevertheless, it reflects the reality of care for SUDs and OMDs in Spain. A further possible limitation could also be the randomization method, which was chosen for its ease of application.Additionally, instead of validated questionnaires, the one used was constructed ad hoc, easy to fill out, and collected the most relevant variables for the objective of the study. It should be clarified that if only pharmacological treatments were chosen for the study, this was due to the methodological difficulties in registering the types of psychological treatments, as they are not registered with the same precision as medicinal ones. Finally, it should be noted that comparability with other studies is limited since there are hardly any studies of such a general nature in our setting.