We read with interest the paper by Spataro et al (2004) considering associations between child sexual abuse and subsequent psychopathology using a prospective cohort design. This study clearly indicates a positive association between child sexual abuse and a range of mental disorders, although not substance use disorders. We think that the authors make an important point in their discussion that this latter absence of an association might be at least-partly due to their methodology for assessing psychiatric outcome. They implemented a diagnostic hierarchy in such a way that when substance use problems were accompanied by other psychiatric disorders, these comorbid conditions were counted and not the substance use.
It is important for the reader to know that substantial comorbidity between substance use disorders and other psychiatric disorders is consistently reported (e.g. Kessler et al, 1997a ). Thus, one could suggest that this prospective study does not demonstrate an association between child sexual abuse and more pure forms of substance use disorders. This would be in line with other findings suggesting a lack of association between childhood trauma (including child sexual abuse) and pure substance use disorders, but a strong relationship between childhood trauma and psychiatric comorbidity in substance use disorders (Kessler et al, 1997b ; de Graaf et al, 2002).