In persons with severe psychiatric disorders, distinct neurocognitive profiles hold differential associations to positive, negative and disorganized symptom dimensions of psychosis. These patterns portend specific functional outcomes, treatment efficacy, and prognoses. Similar associations have not been established in multimorbid samples in which persons present with a complex array of psychiatric symptoms. The objective of this study was to (1) establish neurocognitive profiles in a multimorbid, marginalized sample and (2) investigate their pattern(s) of association with psychiatric symptom dimensions and psychosocial outcomes.

Participants (n=370; Mage = 45 years; 74% male) were precariously housed, substance-using adults with multimorbidity, recruited from Single-Room Occupancy hotels and a community court within the Downtown Eastside of Vancouver, BC, Canada. Data were collected as part of a longitudinal examination consisting of annual, bi-annual, and monthly neurocognitive, psychosocial, and psychiatric assessments. Neurocognitive scores were combined into five cognitive domains (Attentional Control [AC]; Processing Speed [PS]; Fluid Reasoning [Problem Solving and Reversal Learning; Gf]; Encoding and Retrieval [ER]; and Decision Making [DM]) and submitted to a latent profile analysis. The resulting profiles capturing neurocognition were validated on sociodemographic and clinical variables. Finally, the profiles were compared across previously validated, population-distinct factors derived from the Positive and Negative Syndrome Scale (PANSS), as well as on measures of psychosocial functioning.

An optimal goodness-of-fit was reached for a three-profile model (BLRT=127.86, p=.01). Profile 1 (n=207, 55.9%) showed stronger neurocognition (all p<.05), with a within-profile strength in Gf (p<.001). With the exception of ER, Profile 2 (n=109, 29.5%) exhibited inferior neurocognition across all indicators compared to Profile 1 (all p <.05); yet showed a relative, within-profile strength in Gf (p < .01). Profile 3 (n=54, 14.6%) generally displayed comparable impairments to Profile 2. Additionally, their performance on Gf was remarkably low compared to Profiles 1 and 2 (p<.001). Psychiatrically, compared to Profile 1, Profile 2 exhibited more positive/disorganized symptoms and general psychopathology, as well as higher total PANSS (all p <.05), whereas Profile 3 showed the poorest insight/awareness (p<.01). Profiles 2 and 3 had lower levels of adaptive functioning and work productivity compared to Profile 1 (all p<.01).

Three neurocognitive profiles were detected in a sample of precariously housed adults with multimorbidity: one profile of comparatively higher neurocognitive capacity, with less symptoms of psychosis and better psychosocial functioning; a second profile of comparatively poorer neurocognition and psychosocial functioning, with more symptoms of psychosis; and a third profile with a severe deficit in fluid reasoning and poor insight and awareness. Given their poor insight, the third profile may be comprised of particularly vulnerable persons at greater risk of unmet healthcare needs. Interventions to improve these individuals' understanding of their personal health risks might facilitate their capacity to access services. Conversely, individuals from Profile 2 may benefit from outreach programs focusing on medication access and adherence to address their symptoms of psychosis. In sum, our findings suggest that the confluence of neurocognition and psychiatric symptoms may implicate unique treatment approaches and outcomes in precariously-housed persons with multimorbid conditions.

Cognitive dysfunction is prominent in homeless and precariously housed persons, and memory dysfunction is the most pervasive domain. The presence of multimorbid physical and mental illness suggests that several underlying mechanisms of memory impairment may be at play. The serial position phenomenon describes the tendency to best recall the beginning (primacy effect) and last (recency effect) words on a supra-span wordlist. Recency recall engages executive and working-memory systems, whereas primacy recall depends on long-term memory. This study investigates memory dysfunction in a homeless and precariously housed sample by identifying and characterizing unique subtypes of serial position profiles on a test of verbal memory.

Data were used from a 20-year study of homeless and precariously housed adults recruited from an impoverished neighbourhood in Vancouver, Canada. Participants were sub-grouped according to their serial position profile on the Hopkins Verbal Learning Test-Revised using a latent profile analysis (LPA; n = 411). Paired samples t-tests were conducted to determine differences in percent recall from each word-list region within classes. Linear regression analyses were used to examine between-class differences in mean serial position scores and other cognitive measures (memory, attention, processing speed, cognitive control). Covariates included age, sex, and education.

LPA identified two profiles characterized by (1) reduced primacy relative to recency (RP; n = 150); and (2) reduced recency relative to primacy (RR; n = 261). Pairwise comparisons within the RP class showed that recency was better than primacy (p < .001, d = .66) and middle recall (p < .001, d = .52), with no difference between primacy and middle recall (p = .68, d = .04). All pairwise comparisons differed within the RR class (primacy > middle recall: p < .001, d = 1.85; primacy > recency recall: p < .001, d = 1.32; middle > recency recall: p < .05, d = .132). The RP class had worse performance on measures of total immediate (ß = .47, p < .001) and delayed verbal recall (ß = .32, p < .001); processing speed (ß = .20, p < .001); and cognitive control (ß = .22, p < .001). The RR class made more repetition errors (ß = .25, p < .001).

These findings support substantial heterogeneity in memory functioning in homeless and precariously housed individuals. The RP profile was characterized by poorer cognitive functioning across several domains, which suggests multiple contributions to memory impairment, including dysfunction of long-term memory circuitry. The RR profile with their higher number of repetition errors, may experience difficulties with self-monitoring in verbal learning. Subsequent studies will explore the neurobiological underpinnings of these subgroups to further characterize profiles and identify targets for cognitive intervention.

Precariously housed individuals are exposed to multiple adverse factors negatively impacting neurocognitive functioning. Additionally, this population is subjected to poor life outcomes, such as impaired psychosocial functioning. Neurocognitive functioning plays an important role in psychosocial functioning and may be especially critical for precariously housed individuals who face numerous barriers in their daily lives. However, few studies have explicitly examined the cognitive determinants of functional outcomes in this population. Cognitive intraindividual variability (IIV) involves the study of within-person differences in neurocognitive functioning and has been used as marker of frontal system pathology. Increased IIV has been associated with worse cognitive performance, cognitive decline, and poorer everyday functioning. Hence, IIV may add to the predictive utility of commonly used neuropsychological measures and may serve as an emergent predictor of poor outcomes in at-risk populations. The objective of the current study was to examine IIV as a unique index of the neurocognitive contributions to functional outcomes within a large sample of precariously housed individuals. It was hypothesized that greater IIV would be associated with poorer current (i.e., baseline) and long-term (i.e., up to 12 years) psychosocial functioning.

Four hundred and thirty-seven adults were recruited from single-room occupancy hotels located in the Downtown Eastside of Vancouver, Canada (Mage = 44 years, 78% male) between November 2008 and November 2021. Baseline neurocognitive functioning was assessed at study enrolment. Scores from the Social and Occupational Functioning Assessment Scale (SOFAS), the Role Functioning Scale (RFS), the physical component score (PCS) and the mental component score (MCS) of the 36-Item Short Form Survey Instrument were obtained at participants’ baseline assessments and at their last available follow-up assessment to represent baseline and long-term psychosocial functioning, respectively. Using an established formula, an index of IIV was derived using a battery of standardized tests that broadly assessed verbal learning and memory, sustained attention, mental flexibility, and cognitive control. A series of multiple linear regressions were conducted to predict baseline and long-term social and role functioning (average across SOFAS and RFS scores), and PCS and MCS scores from IIV. In each of the models, we also included common predictors of functioning, including a global cognitive composite score, age, and years of education.

The IIV index and the global composite score did not explain a significant proportion of the variance in baseline and long-term social and role functioning (p > .05). However, IIV was a significant predictor of baseline (B = -3.84, p = .021) and long-term (B = -3.58, p = .037) PCS scores, but not MCS scores (p > .05). The global composite score did not predict baseline or long-term PCS scores.

IIV significantly predicted baseline and long-term physical functioning, but not mental functioning or social and role functioning, suggesting that IIV may be a sensitive marker for limitations in everyday functioning due to physical health problems in precariously housed individuals. Critically, the present study is the first to show that IIV may be a useful index for predicting poor long-term health-related outcomes in this population compared to traditional neuropsychological measures.

People living in precarious housing or homelessness have higher than expected rates of psychotic disorders, persistent psychotic symptoms, and premature mortality. Psychotic symptoms can be modeled as a complex dynamic system, allowing assessment of roles for risk factors in symptom development, persistence, and contribution to premature mortality.

The severity of delusions, conceptual disorganization, hallucinations, suspiciousness, and unusual thought content was rated monthly over 5 years in a community sample of precariously housed/homeless adults (n = 375) in Vancouver, Canada. Multilevel vector auto-regression analysis was used to construct temporal, contemporaneous, and between-person symptom networks. Network measures were compared between participants with (n = 219) or without (n = 156) history of psychotic disorder using bootstrap and permutation analyses. Relationships between network connectivity and risk factors including homelessness, trauma, and substance dependence were estimated by multiple linear regression. The contribution of network measures to premature mortality was estimated by Cox proportional hazard models.

Delusions and unusual thought content were central symptoms in the multilevel network. Each psychotic symptom was positively reinforcing over time, an effect most pronounced in participants with a history of psychotic disorder. Global connectivity was similar between those with and without such a history. Greater connectivity between symptoms was associated with methamphetamine dependence and past trauma exposure. Auto-regressive connectivity was associated with premature mortality in participants under age 55.

Past and current experiences contribute to the severity and dynamic relationships between psychotic symptoms. Interrupting the self-perpetuating severity of psychotic symptoms in a vulnerable group of people could contribute to reducing premature mortality.

Homeless and precariously housed individuals experience a high burden of comorbid illnesses, and excess mortality. Cross-sectional studies report a high rate of cognitive impairment. Long-term trajectories have not been well investigated in this group.

To longitudinally assess risks for premature and/or accelerated cognitive ageing, and the relationship with early mortality in homeless and precariously housed people.

This is a 9-year community-based study of 375 homeless and precariously housed individuals from Vancouver, Canada. Annual cognitive testing assessed verbal learning and memory, and inhibitory control. Linear mixed-effects models examined associations between clinical risk factors (traumatic brain injury, psychotic disorders, viral exposure, alcohol dependence) and cognitive change over 9 years. Cox regression models examined the association between cognition and mortality.

Traumatic brain injury and alcohol dependence were associated with decline in verbal memory. Inhibitory control declined, independent of risk factors and to a greater extent in those who died during the study. Better inhibitory control was associated with a 6.6% lower risk of mortality at study entry, with a 0.3% greater effect for each year of life. For each one-point increase in the Charlson Comorbidity Index score at study entry, the risk of mortality was 9.9% higher, and was consistent across age. Adjusting for comorbidities, inhibitory control remained a significant predictor of mortality.

Findings raise the possibility of a premature onset, and accelerated trajectory, of cognitive ageing in this group of homeless and precariously housed people. Traumatic brain injury, alcohol dependence and cognition could be treatment priorities.