A preliminary association study between serotonin transporter (5-HTTLPR), receptor polymorphisms (5-HTR1A, 5-HTR2A) and depression symptom-clusters in a north Indian population suffering from Major Depressive Disorder (MDD).
INTRODUCTION
Major Depressive Disorder (MDD) is a broad heterogeneous diagnostic construct. Previous studies have shown that it can be resolved into several symptom-clusters which are proposed to be associated with single nucleotide polymorphisms (SNPs) of the serotonergic pathway (5-HTTLPR, 5HTR1A, 5-HTR2A).


METHODS AND MATERIAL
In a cross-sectional study conducted at a tertiary level mental health care set-up in north India, 80 out-patients with MDD were evaluated with Montgomery Asberg Depression Rating Scale (MADRS) and then genotyping was done. The different clinical and genetic variables were compared across the factor structures of MADRS. Also, the comparison of the genetic data of cases was done with the pre-existing database of the non-blood related healthy ethnically-matched controls.


RESULTS
There was no significant association between age, gender, other clinical variables, SNPs like 5-HTTLPR SS/SL, rs6295 CC/CG/GG, rs6311GG/GA/AA, rs6313 CC/CT/TT and different factor-structures like 'detachment' consisting of items like concentration difficulty, lassitude, inability to feel; 'psychic anxiety' consisting of suicidal thoughts and inner tension; 'mood-pessimism' consisting of symptoms like apparent sadness, reported sadness, pessimistic thoughts and 'vegetative symptoms' like decreased sleep, poor appetite. Neither there was any association between genotype of the cases compared with the controls.


CONCLUSIONS
No significant association was obtained between the four-factor structures of depression in MADRS and serotonin transporter and receptor SNPs in a study with a small sample size. This study evaluates whether depression symptom-clusters have distinct genotypic determinants and necessitates more comprehensive studies for unravelling the genetic determinants of depression.
['Basu|Aniruddha|A|', 'Chadda|R K|RK|', 'Sood|Mamta|M|', 'Kaur|Harpreet|H|', 'Kukreti|Ritushree|R|']
D000328:Adult D003430:Cross-Sectional Studies D003865:Depressive Disorder, Major D005260:Female D006801:Humans D007194:India D008297:Male D008875:Middle Aged D020641:Polymorphism, Single Nucleotide D044282:Receptor, Serotonin, 5-HT1A D044402:Receptor, Serotonin, 5-HT2A D050486:Serotonin Plasma Membrane Transport Proteins
Major Depressive Disorder Serotonin receptor polymorphism (5-HTR1A,5-HTR2A) Serotonin transporter (5-HTTLPR) polymorphism Symptom clusters of depression