Kasckow J, Youk A, Anderson SJ, Dew MA, Butters MA, Marron MM, Begley AE, Szanto K, Dombrovski A, Mulsant BH, Lenze EJ, Reynolds III CF
Suicide is a public health concern in older adults. Recent cross sectional studies suggest that impairments in executive functioning, memory and attention are associated with suicidal ideation in older adults. It is unknown whether these neuropsychological features predict persistent suicidal ideation. We analyzed data from 468 individuals > age 60 with major depression who received venlafaxine XR monotherapy for up to 16 weeks. We used latent class growth modeling to classify groups of individuals based on trajectories of suicidal ideation. We also examined whether cognitive dysfunction predicted suicidal ideation while controlling for time-dependent variables including depression severity, and age and education. The optimal model using a zero inflated Poisson link classified individuals into four groups, each with a distinct temporal trajectory of suicidal ideation: those with ‘minimal suicidal ideation’ across time points; those with ‘low suicidal ideation’; those with ‘rapidly decreasing suicidal ideation’; and those with ‘high and persistent suicidal ideation’. Participants in the ‘high and persistent suicidal ideation’ group had worse scores relative to those in the “rapidly decreasing suicidal ideation” group on the Color-Word ‘inhibition/switching’ subtest from the Delis-Kaplan Executive Function Scale, worse attention index scores on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and worse total RBANS index scores. These findings suggest that individuals with poorer ability to switch between inhibitory and non-inhibitory responses as well as worse attention and worse overall cognitive status are more likely to have persistently higher levels of suicidal ideation.