Background A number of changes have been proposed and investigated in the criteria for substance use disorders in DSM-5. However, although clinical utility of DSM-5 is a high priority, relatively little of the empirical evidence supporting the changes was obtained from samples of substance abuse patients. Methods Proposed changes were examined in 663 patients in treatment for substance use disorders, evaluated by experienced clinicians using the Psychiatric Research Interview for Substance and Mental Disorders (PRISM). Factor and item response theory analysis was used to investigate the dimensionality and psychometric properties of alcohol, cannabis, cocaine and heroin abuse and dependence criteria, and craving. Results The seven dependence criteria, three of the abuse criteria (hazardous use; social/interpersonal problems related to use; neglect of roles to use), and craving form a unidimensional latent trait for alcohol, cannabis, cocaine and heroin. Craving did not add significantly to the total information offered by the dependence criteria, but adding the three abuse criteria and craving together did significantly increase total information for the criteria sets associated with alcohol, cannabis and heroin. Conclusion Among adult patients in treatment for substance disorders, the alcohol, cannabis, cocaine and heroin criteria for dependence, abuse (with the exception of legal problems), and craving measure a single underlying dimension. Results support the proposal to combine abuse and dependence into a single diagnosis in the DSM-5, omitting legal problems. Mixed support was provided for the addition of craving as a new criterion, warranting future studies of this important construct in substance use disorders.

The interpersonal psychological theory of suicide (IPTS) was used to examine suicidal thoughts and behaviors among 129 transgender and gender nonconforming (TGNC) youth. Youth were categorized according to their gender identities: female-to-male (FTM), male-to-female (MTF), female-to-different-gender (FTDG), and male-to-different gender (MTDG). Higher percentages of suicidal ideation were reported by FTDG and FTM youth; and higher percentages of suicide attempts by FTDG and MTDG youth. Perceived burdensomeness and thwarted belongingness were significantly related to suicidal ideation and/or suicide attempts. Experiences of painful, provocative and harmful events and acquired capability significantly predicted suicide attempts. The findings support IPTS in explaining suicidal behaviors among TGNC youth. Implications for prevention and intervention efforts are discussed.

Item response theory (IRT) has been increasingly utilized in psychiatry for the purpose of describing the relationship among items in psychiatric disorder symptom batteries hypothesized to be indicators of an underlying latent continuous trait representing the severity of the psychiatric disorder. It is common to find zero-inflated (ZI) data such that a large proportion of the sample has none of the symptoms. It has been argued that standard IRT models of psychiatric disorder symptoms may be problematic due to the unipolar nature of many clinical traits. In the current article, the authors propose to address this by using a mixture model to approximate the unknown latent trait distribution in the IRT model while allowing for the presence of a non-pathological subgroup. The basic idea is that instead of assuming normality for the underlying trait, the latent trait will be allowed to follow a mixture of normals including a degenerate component that is fixed to represent a non-pathological group for whom the psychiatric symptoms simply are not relevant and hence are all expected to be zero. The authors demonstrate how the ZI mixture IRT method can be implemented in Mplus and present a simulation study comparing its performance with a standard IRT model assuming normality under different scenarios representative of psychiatric disorder symptom batteries. The model incorrectly assuming normality is shown to have biased discrimination and severity estimates. An application further illustrates the method using data from an alcohol use disorder criteria battery.

No abstract