Substance Use Disorders: Findings from a Longitudinal Study of Individuals with and without a History of Developmental Language Disorders

Objective: To study the prevalence and types of substance use disorders (SUDs) in adults diagnosed during childhood as having a developmental language disorder (DLD). Patients and Methods: The prevalence rates and types of SUDs in a clinical sample of 469 individuals diagnosed during childhood as having a DLD were compared with SUDs in 2,345 matched controls from the general population without a known history of DLD using data from the nationwide Danish Psychiatric Central Register (DPCR). The average observation time was 34.7 years, and the mean age at follow-up was 35.8 years. Results:Of the 469 individuals with DLD, 12 (2.6%) appeared in the DPCR with an SUD diagnosis, compared with 46 (2.0%) in the control group (p = 0.41; OR 1.3; 95% CI 0.7-2.5). Specific SUDs occurred with a low frequency in both groups. Only cocaine-related disorders were significantly associated with DLD (p = 0.03). Variables at assessment in childhood, i.e. gender, IQ, the presence of a receptive language disorder, and the degrees of receptive and expressive language disorders were not associated with an SUD diagnosis in the DPCR at follow-up. Conclusion: Our findings do not support the hypothesis that DLD is a risk factor for SUD in adulthood.