Relationship between cognitive and non-cognitive symptoms of delirium

Aim: To study relationship between the cognitive and the non-cognitive symptoms of delirium. Methods: Eighty-four patients referred to psychiatry liaison services and met DSM-IVTR criteria of delirium were assessed using the Delirium Rating Scale Revised-1998 (DRSR-98) and Cognitive Test for Delirium (CTD). Results: The mean DRS-R-98 severity score was 17.19 and DRS-R-98 total score was 23.36. The mean total score on CTD was 11.75. The mean scores on CTD were highest for comprehension (3.47) and lowest for vigilance (1.71). Poor attention was associated with significantly higher motor retardation and higher DRS-R-98 severity scores minus the attention scores. There were no significant differences between those with and without poor attention. Higher attention deficits were associated with higher dysfunction on all other domains of cognition on CTD. There was significant correlation between cognitive functions as assessed on CTD and total DRS-R-98 score, DRS-R-98 severity score and DRS-R-98 severity score without the attention item score. However, few correlations emerged between CTD domains and CTD total scores with cognitive symptom total score of DRS-R-98 (items 9-13) and non-cognitive symptom total score of DRS-R-98 (items 1-8). Conclusions: Our study suggests that in delirium, cognitive deficits are quite prevalent and correlate with overall severity of delirium. Attention deficit is a core symptom of delirium.