[Association between mood characteristics and polymorphisms of glial cell line-derived neurotrophic factor (GNDF) in...

Glial cell line-derived neurotrophic factor (GNDF) plays an important role in the development and synaptic plasticity of dopaminergic neurons, thus it could be an important therapeutic factor in Parkinson's disease. Results from candidate gene studies of GDNF in psychiatric disorders are contradictory. Moreover, the possible association between GDNF polymorphisms and major- or bipolar depression has not been studied to date. Recently, our research group has published an association between two GDNF polymorphisms (rs3812047, rs3096140) and the individual variability of anxiety measured by the Hospital Anxiety and Depression Scale (HADS) on a non-clinical sample. In the present study we further analyzed this association on a sample with major- and bipolar depression: we used data from 183 MDD, 116 BP, and 1172 control subjects and tested effect of GDNF rs3812047 and rs3096140 polymorphisms on mood disorders. The case control design did not show significant differences in the genotype distribution of BP or MDD versus control patients. However, in the bipolar group subjects with rs3812047 A allele showed a significantly higher anxiety and depression mean score then subjects with G allele (p=0.043). This result supports our previous findings demonstrated on a non-clinical sample. Interestingly we found an opposite effect of the rs3812047 using data from MDD patients: subjects with the G allele had higher depression scores (p=0.012). An interaction effect of patient subgroups and genetic variants of the rs3812047 was observed for both HADS subscales (anxiety: p=0.029; depression: 0.004). In summary, we confirmed the previously published association between the rs3812047 A allele and mood characteristics on the bipolar sample, and an effect in the opposite direction was detected in the patient group with major depression.