Neurocognitive profiles of marginally housed persons with comorbid substance dependence, viral infection, and psychiatric illness

Abstract

Introduction: Individuals living in single-room occupancy (SRO) hotels constitute a socially marginalized group with exposure to multiple factors with adverse effects on neurocognition, including substance use, viral infection, psychiatric illness, and brain injury. Consequently, marked heterogeneity in neurocognitive functioning is observed. This study aimed to identify and describe distinct neurocognitive profiles within a marginally housed sample. Method: Two hundred and forty-nine (N = 249) SRO hotel residents (mean age = 43.5 years) were recruited. A battery of tests assessed neurocognition across six domains: premorbid IQ, verbal memory, attention, inhibition, mental flexibility, and decision making. Clinical examinations collected information pertaining to substance use and psychiatric diagnoses, viral infection, psychiatric symptoms, risk behaviors, and everyday functioning. Cluster analysis was used to identify subgroups of individuals with similar neurocognitive profiles and was supplemented with a discriminant function analysis. Analyses of variance and chi-square tests were used to validate the derived clusters on key clinical and functional variables. Results: A three-cluster solution was found to be optimal. Cluster 1 (n = 59) presented as overall higher functioning, whereas Cluster 3 (n = 87) exhibited overall lower functioning with a relative strength in decision-making skills. Cluster 2 (n = 103) was characterized by neurocognitive abilities that generally bisected the performance of the other groups, but with a relative weakness in decision-making skills. Discriminant function analysis indicated the six neurocognitive variables comprised two underlying dimensions that accounted for between-group variance. Clusters meaningfully differed on demographics, substance use, viral exposure, psychiatric symptoms, neurological soft signs, and risk behavior. Conclusion: Neurocognitive functioning provides the basis for identifying meaningful subgroups of marginally housed individuals, which can be reliably differentiated on key variables. This approach facilitates an understanding of the neurocognitive dysfunction and associated vulnerabilities of marginalized persons and ultimately may elucidate intervention targets.

Keywords:

• Cluster analysis
• Neurocognition
• Substance-related disorders
• Dual diagnosis
• Substandard housing

The authors would like to thank the HOTEL team for their assistance with data collection and management. Portions of this work were presented in poster format at the 3rd Schizophrenia International Research Society conference.

Notes

¹ Due to unavailability for follow-up, 36.1% of participants had TLFB data available for only two months, while 4.8% had TLFB data for one month; 6.8% of participants were missing TLFB for all three months surrounding the date of neurocognitive testing.

² Only one bivariate relationship did not correspond as expected. Profile 1 of the k-means algorithm correlated more strongly with Profile 3 of the Ward’s algorithm than with Ward’s Profile 1 (see Table 2).

³ Indeed, in the current sample, discrete neurocognitive domains were significantly correlated with scores on SOFAS (sustained attention: r = .15, p = .022; decision making: r = .19, p = .002) and RFS (decision making: r = .17, p = .010).