Impact of Mental Illness with Comorbid Substance Use on Psychosocial Conditions Among Colorado's Male Offenders: An Analysis of a One-Year Longitudinal Study

Purpose: Psychosocial conditions of offenders with comorbidity of substance use (SU) and mental illnesses (MI) have been a concern to professionals from both mental health and substance rehabilitation services inside and outside prisons. There were a collection of studies conducted on ever-growing prevalence of dual diagnoses and severe consequences including challenging behaviors, psychosocial conditions and psychotic symptoms among offenders. However, there were few longitudinal studies within criminal justice system investigating how treatment being effective to various psychosocial conditions of offenders with MI with comorbid SU. This study examined the long-term changes in behavioral, psychosocial and psychotic conditions of the offenders with comorbidity under appropriate treatment; explored and compared their changing trajectory to that of offenders with MI alone, SU alone, and no diagnosis; and discussed roles of their violent crime history, traumatic experience and emotional stability in the changing process.

Methods: The data were obtained from the Evaluation of the Psychological Effects of Administrative Segregation in Colorado study on 270 male offenders except for masked demographic information. This study included 1620 observations from all the participants over 6 time points during 1.5 years. Each of the structured measurement tools were used 6 times to assess behavioral, psychosocial (adjusting emotions), and psychotic outcome and time-varying and non-time-varying covariates of participants who were classified into diagnostic groups as having SU and MI (24.4%), SU alone (14.8%), MI alone (24.8%), and no diagnosis (35.9%). Mixed linear models including the hierarchical model and the growth curve model were used to examine the changing patterns of participants’ symptoms across all diagnostic groups.

Results: Results indicated that over time offenders with comorbid of SU and MI, compared to ones with no diagnosis, had increasingly worse condition in behavioral problems (β=.011, p=.039); had faster improvement rate in psychosocial functioning (β=-.014, p=.004) and psychotic symptoms (β=-.010, p=.035). Moreover, in terms of psychotic symptoms, Individuals with comorbidity had more severe condition than the ones with neither diagnosis on the baseline (β=.19, p=.001), and over time had significant faster improvement rate than the ones with SU alone (χ²(2)=19.29, p<.001) and MI alone (χ²(2)=10.59, p=.005). Individuals with violent crime history compared to those without in the past had more severe behavioral symptoms (β=.059, p=.033). Traumatic experience negatively influenced one’s psychosocial functioning (β=.27, p<.001) and psychotic symptoms (β=.42, p<.001). Emotional instability negatively impacted one’s behavioral problems (β=.052, p=.028), psychosocial functioning (β=.25, p<.001), and psychotic symptoms (β=.56, p<.001).

Implications: The findings suggest that offenders with comorbid SU and MI being provided with treatment will have difficulties improving their behavioral problems and psychotic symptoms over time compared to ones without. Further the study suggests that the ones with comorbidity did not get better than the ones with MI alone over time due to the untended substance use. This study underscores the need to address underdiagnosed substance use among offenders with MI; the necessity of having appropriate treatment for substance use and addiction among people with MI; and the role of intervention programs for offenders’ traumatic experience and emotional instability in improving their various symptoms.