Participant Characteristics
The study included 268 participants, with a mean age of 36.5 years (SD = 12.1) and an average of 8.0 years of schooling (SD = 3.7). The majority of the participants were male (61.6%), unemployed (86.7%), and single (67.9%). The average duration of the primary psychiatric diagnosis was 9.0 years (SD = 9.9), with a mean of 3.4 lifetime hospitalizations (SD = 5.1) and 1.3 hospitalizations in the last year (SD = 0.8). The detailed sociodemographic characteristics of the study sample are presented in Tables 1 and 2.
Table 1
Sociodemographic and Substance Use Characteristics of Hospitalized Psychiatric Patients. This table summarizes the sociodemographic and substance use characteristics of a sample of 268 patients admitted to a psychiatric hospital.
Variables | Categories | Frequency % |
Sex | Male | 165 (61.6) |
| Female | 103 (38.4) |
Marital status | Single | 182 (67.9) |
| Married/Free union | 50 (18.7) |
| Divorced/separated | 26 (9.7) |
| Widower | 10 (3.7) |
Occupation | Employed | 36 (13.3) |
| Unemployed | 234 (86.7) |
Schooling | No schooling | 21 (7.8) |
| Elementary school | 106 (39.6) |
| Middle school | 87 (32.5) |
| High school | 38 (14.2) |
| Bachelor | 16 (6.0) |
Residency | Metropolitan area | 167 (62.3) |
| State resident (not from the metropolitan area) | 83 (31.0) |
| Another state | 18 (6.7) |
Table 2
Clinical Characteristics and Substance Use Measures of Hospitalized Patients. The table shows means and standard deviations for continuous variables like age, years of schooling, disease duration, treatment duration, hospitalization duration, and number of psychotropic drugs prescribed at discharge. It also displays frequencies and percentages for categorical variables including scores on the Global Assessment of Functioning (GAF) scale upon admission and discharge, substance use at some point in life, substance use in the last 3 months, and the severity of substance use.
Variables | Mean (ED) |
Years of schooling | 8.0 (3.7) |
Age | 36.5 (12.1) |
Disease duration | 9.0 (9.9) |
Treatment duration | 7.1 (9.6) |
Hospitalizations in the last year | 1.3 (0.8) |
Lifetime hospitalizations | 3.4 (5.1) |
Hospitalization duration (days) | 28.2 (22.9) |
Number of psych drugs prescribed on discharge | 2.2 (0.9) |
GAF score (admission) | 17.1 (5.9) |
GAF score (discharge) | 58.5 (13.5) |
Table 1 and Table 2 here
The three most common discharge diagnoses were schizophrenia (42.2%), substance-induced psychotic disorder (22.0%), and bipolar disorder (17.9%), collectively accounting for 82.1% of the sample.
Patterns of Substance Use
Within the last three months, the prevalence of substance use was as follows: tobacco (46.6%), alcohol (45.9%), cannabis (34.3%), and methamphetamines (32.8%). Toxicological urine tests conducted on 76.9% (n = 206) of the participants within the first 24 hours of admission revealed the presence of cannabis (21.8%), methamphetamines (10.7%), benzodiazepines (5.3%), and cocaine (0.5%) (Table 3).
Table 3
Substance abuse in the last three months. This table shows the prevalence of substance abuse in the last three months among 268 participants. It categorizes substances into ten groups: Tobacco, Ethanol (Alcohol), Cannabis, Methamphetamines, Cocaine, Benzodiazepines, Inhalants, Hallucinogens, Opioids, and "Other." For each substance, the table displays the number of participants who reported using it (frequency) and the corresponding percentage of the total sample (%).
Substance | Frequency (%) |
Consumption | No consumption |
Tobacco | 125 (46.6) | 143 (53.4) |
Ethanol | 123 (45.9) | 145 (54.1) |
Cannabis | 92 (34.3) | 176 (65.7) |
Methamphetamines | 88 (32.8) | 180 (67.2) |
Cocaine | 28 (10.4) | 242 (89.6) |
Benzodiazepines | 19 (7.1) | 249 (92.9) |
Inhalants | 17 (6.3) | 253 (93.7) |
Hallucinogens | 2 (0.7) | 266 (99.3) |
Opioids | 1 (0.4) | 269 )99.6) |
Table 3 here
Severity of Substance Use
The severity of substance use, as assessed by the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST) scores, indicated that methamphetamines and cannabis had the highest proportions of severe consumption among the participants. Specifically, 48.9% of methamphetamine users and 43.5% of cannabis users reported severe consumption levels (ASSIST score ≥ 27). For alcohol use, 43.1% reported moderate consumption, and 13.0% reported severe consumption. Regarding tobacco use, 71.2% reported moderate consumption, and 14.4% reported severe consumption (Fig. 1).
Figure 1 here
Factors Associated with Substance Use
Multivariate logistic regression models were constructed to identify factors associated with alcohol, cannabis, and methamphetamine use in the last three months.
Alcohol Use
The final logistic regression model for alcohol use had an explanatory power of 73.72%. Tobacco use (β = 2.17, 95% CI: 1.49 to 2.87, p < 0.001) and cannabis use (β = 1.30, 95% CI: 0.50 to 2.13, p < 0.01) were significant predictors of alcohol use.
Cannabis Use
The final logistic regression model for cannabis use had an explanatory power of 85.75%. Significant predictors of cannabis use included fewer years of schooling (β = -1.73, 95% CI: -3.33 to 0.16, p < 0.05), alcohol use (β = 1.67, 95% CI: 0.70 to 2.69, p < 0.001), substance-induced psychotic disorder diagnosis (β = 1.52, 95% CI: 0.48 to 2.62, p < 0.01), tobacco use (β = 1.45, 95% CI: 0.51 to 2.42, p < 0.01), and methamphetamine use (β = 1.35, 95% CI: 0.47 to 2.26, p < 0.01).
Methamphetamine Use
The final logistic regression model for methamphetamine use had an explanatory power of 86.92%. Significant predictors of methamphetamine use included substance-induced psychotic disorder diagnosis (β = 2.33, 95% CI: 1.33 to 3.40, p < 0.001), cocaine use (β = 1.82, 95% CI: 0.53 to 3.31, p < 0.01), cannabis use (β = 1.50, 95% CI: 0.56 to 2.47, p < 0.01), tobacco use (β = 1.25, 95% CI: 0.08 to 2.43, p < 0.05), and younger age (β = -0.05, 95% CI: -0.09 to -0.01, p < 0.01). The summary of the three final models used to predict methamphetamine, cannabis, and alcohol consumption is presented in Fig. 2.
Figure 2 here
In summary, the study findings revealed high rates of substance use, particularly tobacco, alcohol, cannabis, and methamphetamines, among individuals with severe mental illness. The severity of substance use was highest for methamphetamines and cannabis. Additionally, various sociodemographic and clinical factors, such as substance-induced psychotic disorder diagnosis, tobacco and other substance use, and younger age, were associated with an increased likelihood of methamphetamine, cannabis, and alcohol use.