Aim: The objective of this study was to develop and validate a brief tool, the Dual Diagnosis Screening Instrument (DDSI), to screen psychiatric disorders in substance users in treatment and nontreatment-seeking samples. Methods: A total of 827 substance users (66.5% male, mean age 28.6 ± 9.9 years) recruited in treatment (in- and outpatient) and nontreatment (substance user volunteers in university research studies) settings were assessed by trained interviewers using the DDSI and the Psychiatric Research Interview for Substance and Mental Disorders (PRISM) as the criterion standard. Both instruments were administered blind to the results of the other. Disorders obtained with the DDSI were compared to lifetime diagnoses obtained with the PRISM. Sensitivity, specificity, negative, and positive predictive values were estimated. Also test-retest reliability of the DDSI was assessed. Results: The DDSI showed a high sensitivity (=80%) for identifying lifetime depression, mania, psychosis, panic, social phobia, and specific phobia disorders. Specificity was =82% for those diagnoses. Test-retest κ showed excellent agreement (range 81-95%). The mean duration of the DDSI administration was 16.8 ± 2.5 min. Conclusion: The DDSI is a valid and easy-to-administer screening tool to detect possible psychiatric comorbidity among substance users.

The International Classification of Diseases–11th revision (ICD-11) classification of personality disorders is the official diagnostic system that is used all over the world, and it has recently been renewed. However, as yet very few data are available on its performance. This study examines the Personality Inventory for ICD-11 (PiCD), which assesses the personality domains of the system, and the Standardized Assessment of Severity of Personality Disorder (SASPD), which determines severity. The Spanish versions of the questionnaires were administered to a community (n = 2,522) and a clinical sample (n = 797). Internal consistency was adequate in the PiCD (α = .75 to .84) but less so in the SASPD (α = .64 and .73). Factor analyses suggested a unidimensional or bidimensional structure for severity, while revealing that the personality trait qualifiers are organized into four factors: negative affectivity, detachment, dissociality, and a bipolar domain of disinhibition–anankastia. The mutual relationships between traits and severity were analyzed, as well as the ability of the whole system to identify clinical subjects. Although further improvements are required, the results generally support the use of the PiCD and the SASPD and help substantiate the new ICD-11 taxonomy that underlies them.

Major depressive disorder (MDD) is the most prevalent comorbid mental disorder among people with substance use disorders. The MDD can be both primary and substance-induced and its accurate diagnosis represents a challenge for clinical practice and treatment response. Recent studies reported alterations in the circulating expression of inflammatory mediators in patients with psychiatric disorders, including those related to substance use. The aim of the study was to explore TNF-α, IL-1β, CXCL12, CCL2, CCL11 (eotaxin-1) and CX3CL1 (fractalkine) as potential biomarkers to identify comorbid MDD and to distinguish primary MDD from substance-induced MDD in patients with substance disorders. Patients diagnosed with cocaine (CUD, n = 64) or alcohol (AUD, n = 65) use disorders with/without MDD were recruited from outpatient treatment programs [CUD/non-MDD (n = 31); CUD/primary MDD (n = 18); CUD/cocaine-induced MDD (N = 15); AUD/non-MDD (n = 27); AUD/primary MDD (n = 16) and AUD/alcohol-induced MDD (n = 22)]. Sixty-two healthy subjects were also recruited as control group. Substance and mental disorders were assessed according to “Diagnostic and Statistical Manual of Mental Disorders, 4^th edition, text revision” (DSM-IV-TR) and a blood sample was collected for determinations in the plasma. The cocaine group showed lower TNF-α (p<0.05) and CCL11 (p<0.05), and higher IL-1β (p<0.01) concentrations than the control group. In contrast, the alcohol group showed higher IL-1β (p<0.01) and lower CXCL12 (p<0.01) concentrations than the control group. Regarding MDD, we only observed alterations in the cocaine group. Thus, CUD/MDD patients showed lower IL-1β (p<0.05), CXCL12 (p<0.05) and CCL11 (p<0.05), and higher CXC3CL1 (p<0.05) concentrations than CUD/non-MDD patients. Moreover, while CUD/primary MDD patients showed higher CCL11 (p<0.01) concentrations than both CUD/non-MDD and CUD/cocaine-induced MDD patients, CUD/cocaine-induced MDD patients showed lower CXCL12 (p<0.05) concentrations than CUD/non-MDD patients. Finally, a logistic regression model in the cocaine group identified CXCL12, CCL11 and sex to distinguish primary MDD from cocaine-induced MDD providing a high discriminatory power. The present data suggest an association between changes in inflammatory mediators and the diagnosis of primary and substance-induced MDD, namely in CUD patients.

Major depression disorder (MDD) is the most prevalent psychiatric comorbid condition in cocaine use disorder (CUD). The comorbid MDD might be primary-MDD (CUD-primary-MDD) or cocaine-induced MDD (CUD-induced-MDD), and their accurate diagnoses and treatment is a challenge for improving prognoses. This study aimed to assess the tryptophan/serotonin (Trp/5-HT) system with the acute tryptophan depletion test (ATD), and the kynurenine pathway in subjects with CUD-primary-MDD, CUD-induced-MDD, MDD and healthy controls. The ATD was performed with a randomized, double-blind, crossover, and placebo-controlled design. Markers of enzymatic activity of indoleamine 2,3-dioxygenase/tryptophan 2,3-dioxygenase, kynurenine aminotransferase (KAT) and kynureninase were also established. Following ATD, we observed a decrease in Trp levels in all groups. Comparison between CUD-induced-MDD and MDD revealed significant differences in 5-HT plasma concentrations (512 + 332 ng/mL vs. 107 + 127 ng/mL, p = 0.039) and the Kyn/5-HT ratio (11 + 15 vs. 112 + 136; p = 0.012), whereas there were no differences between CUD-primary-MDD and MDD. Effect size coefficients show a gradient for all targeted markers (d range 0.72–1.67). Results suggest different pathogenesis for CUD-induced-MDD, with lower participation of the tryptophan system, probably more related to other neurotransmitter pathways and accordingly suggesting the need for a different pharmacological treatment approach.