OBJECTIVES: Suicidal ideation is an uncommon but worrisome symptom than can 
emerge during antidepressant treatment. We have described earlier the 
association between treatment-emergent suicidal ideation (TESI) and markers in 
genes encoding glutamate receptor subunits GRIK2 and GRIA3. The present 
genome-wide association study was conducted to identify additional genetic 
markers associated with TESI that may help identify individuals at high risk who 
may benefit from closer monitoring, alternative treatments, and/or specialty 
care.
METHODS: A clinically representative cohort of outpatients with nonpsychotic 
major depressive disorder enrolled in the Sequenced Treatment Alternatives to 
Relieve Depression (STAR*D) trial were treated with citalopram under a standard 
protocol for up to 14 weeks. DNA samples from 90 White participants who 
developed TESI and a sex-matched and race-matched equal number of treated 
participants who denied any suicidal ideas were genotyped with 109 365 single 
nucleotide polymorphisms on the Illumina's Human-1 BeadChip.
RESULTS: One marker was found to be associated with TESI in this sample at the 
experiment-wide adjusted P less than 0.05 level (marker rs11628713, allelic P = 
6.2x10, odds ratio = 4.7, permutation P = 0.01). A second marker was associated 
at the experiment-wide adjusted P = 0.06 level (rs10903034, allelic P = 3.02x10, 
odds ratio = 2.7, permutation P = 0.06). These markers reside within the genes 
PAPLN and IL28RA, respectively. PAPLN encodes papilin, a protoglycan-like 
sulfated glycoprotein. IL28RA encodes an interleukin receptor.
CONCLUSION: Together with our earlier report, these findings may shed light on 
the biological basis of TESI and may help identify patients at increased risk of 
this potentially serious adverse event.