67 Examination of Neuropsychological Functioning and Current Suicidal Ideation and Suicide Attempt History in Individuals with Severe Mental Illness
Authors: Keller Amber V. , Parrish Emma M. , Chalker Samantha A. , Twamley Elizabeth W. , Pinkham Amy E. , Harvey Philip D. , Depp Colin A. 
Published: December 2023

Objective:

Suicide risk among individuals with psychosis is elevated compared to the general population (e.g., higher rates of suicide attempts [SA] and completions, more severe lethality of means). Importantly, suicidal ideation (SI) seems to be more predictive of near-term and lifetime SAs in people with psychosis than in the general population. Yet, many randomized controlled trials in psychosis have excluded individuals with suicidality. Additionally, research suggests better cognitive and functional abilities are associated with greater suicide risk in psychotic disorders, which is dissimilar to the general population, but studies examining the link between cognition and suicidality are scarce. Because neuropsychological abilities can affect how individuals are able to attend to their environment, solve problems, and inhibit behaviors, further work is needed to consider how they may contribute to suicide risk in people with psychotic disorders. We sought to examine associations between neuropsychological performance and current SI and SA history in a large sample of individuals with psychosis.

Participants and Methods:

176 participants with diagnoses of schizophrenia, schizoaffective disorder, and bipolar disorder with psychotic features completed clinical interviews, a neuropsychological assessment (MATRICS Consensus Cognitive Battery subtests), and psychiatric symptom measures (Positive and Negative Syndrome Scale [PANSS]; Montgomery-Asberg Depression Rating Scale [MADRS]. First, participants were divided into groups based on their current endorsement of SI in the past month on the Colombia Suicide Severity Rating scale (C-SSRS): those with current SI (SI+; n=86) and without current SI (SI-; n=90). We also examined lifetime history of SA (n=114) vs. absence of lifetime SA (n=62). Separate t-tests, chi-square tests, and logistic regressions were used to examine associations between neuropsychological performance and the two dichotomous outcome variables (current SI; history of SA).

Results:

The SI groups did not differ on diagnosis, demographics (e.g., age, gender, race, ethnicity, years of education, premorbid functioning), or on positive and negative symptoms. The SI+ group reported more severe depressive symptoms (t(169)= -5.90, p<.001) and had significantly worse performance on working memory tests than the SI- group (t(173)=2.28, p=.024). Logistic regression revealed that working memory performance uniquely predicted current SI+ group membership above and beyond depressive symptoms (B= -.040; OR= .96; 95% CI [.93, .99]; p= .034). The SA groups did not significantly differ on demographic variables or on positive/negative symptoms, but those with a history of SA had more severe depressive symptoms (t(169)= -2.80, p=.006) and worse performance on tests of working memory (t(173)=2.16, p=.033) and processing speed (t(166)=2.28, p=.024) than did those without a history of SA. Logistic regression demonstrated that after controlling for depressive symptom severity, working memory and processing speed did not predict unique variance in SA history (p=.25).

Conclusions:

Worse working memory performance was associated with SI in the past month in individuals with psychotic disorders. Although our finding is consistent with literature in other psychiatric populations, it conflicts with existing psychosis literature. Thus, a more nuanced examination of how cognition relates to SI/SA in psychosis is warranted to identify and/or develop optimal interventions.