Interactions between a serotonin transporter gene, life events and social support on suicidal ideation in Korean elders.
BACKGROUND
The functional polymorphism in the serotonin transporter gene linked promoter region (5-HTTLPR) may modify associations between environmental stressors and suicidality in adolescents and working-age adults. We investigated whether the 5-HTTLPR s/l polymorphism interacts with stressful life events (SLEs) and social support deficits (SSDs) on late-life suicidal ideation.


METHODS
732 Korean community residents aged 65+ were evaluated and, of 639 without suicidal ideation, 579 (90.6%) were followed two years later. Prevalence and incidence of suicidal ideation was ascertained. Information on SLEs and SSDs were gathered, and covariates included socio-demographic characteristics, depressive symptoms, cognitive function, and disability.


RESULTS
Significant interactions were observed between 5-HTTLPR genotype, SLEs and SSDs on both prevalence and incidence of suicidal ideation after adjustment for covariates. The associations of SLEs and SSDs with suicidal ideation were strengthened in combination with higher numbers of s alleles, and were only significant predictors in those with s/s genotype. A significant three-way interaction between 5-HTTLPR genotype, SLEs and SSDs was also found.


CONCLUSIONS
The generalizability of suicidal ideation as a marker of suicidality should be considered.


CONCLUSIONS
Gene-environment interactions on suicidal behavior are therefore identifiable even in old age.
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea.
Jae-Min
JM
Kim
Section of Epidemiology, Institute of Psychiatry, King׳s College, London, UK.
Robert
R
Stewart
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea.
Sung-Wan
SW
Kim
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea.
Hee-Ju
HJ
Kang
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea.
Seon-Young
SY
Kim
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea.
Ju-Yeon
JY
Lee
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea.
Kyung-Yeol
KY
Bae
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea.
Il-Seon
IS
Shin
Department of Psychiatry & Depression Clinical Research Centre, Chonnam National University Medical School, Kwangju, Republic of Korea. Electronic address: jsyoon@chonnam.ac.kr.
Jin-Sang
JS
Yoon
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D059647:Gene-Environment Interaction; D005838:Genotype; D006801:Humans; D008016:Life Change Events; D008297:Male; D011110:Polymorphism, Genetic; D056910:Republic of Korea / Q000453:epidemiology; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012944:Social Support; D059020:Suicidal Ideation
D050486:Serotonin Plasma Membrane Transport Proteins
5-HTTLPR; Aged; Gene–environment interaction; Life stress; Social support; Suicidal ideation