Depression is associated with significantly poorer cognitive function in patients with a new diagnosis of systemic lupus erythematosus (SLE) as well as in patients with established disease. Intervention trials of antidepressants for a Calgary Depression Scale (CDS) score higher than 6 are clearly indicated in depressed patients with SLE who have cognitive impairment.
Petri and colleagues performed cognitive function testing (Automated Neuropsychological Assessment Metrics [ANAM]) in 111 patients known to have SLE for less than 9 months. The CDS was used to measure depression.
Slightly fewer than one-third (31%) of the study participants were depressed—as indicated by a CDS score higher than 6—an incidence similar to that found among persons with long-standing SLE. The depressed patients were clinically and demographically similar to the other study participants but were more likely to have fibromyalgia and fatigue. Like persons with prolonged SLE, the depressed persons performed poorly on ANAM throughput measures of continuous performance, simple reaction time, and memory. Depression was not linked with poor performance on mathematical or spatial processing tests.
The authors suggested that future studies be directed toward investigating whether management of depression improves cognitive impairment and exploring the neurological mechanisms.