We detected several significant differences between the IA and VA groups (Table 1). All patients met the ICD-10 criteria for current substance dependence or abuse. During the 6 months before admission, significantly more patients in the IA group had injected illicit drugs and at a higher frequency than patients in the VA group. In addition, patients admitted involuntarily had experienced more overdoses during their lifetime compared with patients admitted voluntarily. However, the burden of psychological symptoms (Symptom Checklist-90-R and suicide attempts) was higher in the VA than in the IA group. Significantly more patients admitted involuntarily received ‘no mental diagnoses’, but among all patients with comorbid mental disorders, no significant differences were detected between the IA and VA groups regarding mental health diagnoses. There were significantly more female patients in the IA group than in the VA group (49% vs. 27%, respectively).Table 1Baseline sociodemographic variables and mental stress scores for patients with substance use disordersVariableIAVA P-valueAge, years, mean (SD)28.52 (10.6)30.43 (8.6)0.177Female, n (%)35 (27.1)31 (49)0.002Education Years in primary school and high school, mean (SD)10.58 (1.4)10.63 (1.6)0.848 Years in college and university, mean (SD)0.28 (0.9)0.18 (0.8)0.442Sources of financial supporta, b Employment, n (%)6 (10)21 (17)0.236 Public welfare benefits, n (%)57 (95)109 (86)0.064 Partner, family, or friends, n (%)17 (29)37 (30)0.916 Illegal activity, n (%)23 (40)45 (37)0.691Living arrangementb With partner, n (%)7 (12)11 (9)0.512 Alone, n (%)30 (52)57 (46)0.499 With family, n (%)9 (16)25 (20)0.440 No stable arrangements, n (%)9 (16)15 (12)0.539 In a controlled environment, n (%)2 (3)15 (12)0.060Treated by a physician for somatic diseasesb, n (%)23 (43)27 (23)0.015Injecting illicit drugb, n (%)42 (71)58 (46)0.001Alcoholic delirium tremensc, n (%)8 (14)15 (12)0.731Overdoses on drugsc, n (%)40 (70)61 (50)0.010Suicide attemptsc, n (%)21 (36)69 (56)0.015Mental stress score SCL-90-R GSI, mean (SD)1.00 (0.7)1.31 (0.7)0.004 Number of patients63129 Abbreviations: IA involuntarily admitted, VA voluntarily admitted, SD standard deviation, SCL-90-R GSI Symptom Check List-90-Revised, Global Symptom Index aSome participants had more than one source of financial support bLast 6 months before admission cLifetime prevalence