Conclusion : Low folate and B12 serum levels seem to be associated with  depression in the aged .
Objectives : To systematic ally review and meta-analyse existing evidence on the association between folate/B12 , and depression among the aged people .
Plasma pterins and folate in late life depression: The Rotterdam Study
Tetrahydrobiopterin is a cofactor in the synthesis of monoamine neurotransmitters . High neopterin levels generally signal increased immune activation . Both pterins have been investigated in several small clinical studies of depressed patients with conflicting results . Therefore , we examined the relation of plasma biopterin and neopterin with depression in a population -based study . We also studied the association of pterins with folates in depressed persons as this vitamin is required for pterin bio synthesis . We screened 3884 adults aged 60 years and over for depressive symptoms . Screen positive subjects had a psychiatric interview to diagnose DSM-IV disorder .  Plasma pterins and serum folate  were determined in all persons with depressive symptoms ( n=238 ) and r and omly selected non-depressed persons ( n=357 ) . We found no association between the concentration of biopterin or neopterin with depressive symptoms or depressive disorders . However , in depressed persons the relation between pterins and folates was different than in the non-depressed , i.e. neopterin concentrations increased with folate levels in persons with depressive symptoms ( 0.09 per log(nmol/l folate ) ; 95 % CI=0.01 , 0.18 , P=0.03 ) , but not in non-depressed persons ( -0.07 per log(nmol/l folate ) ; 95 % CI=-0.17 , 0.03 , P=0.18 ) . The interaction between depressive symptoms , folate and neopterin was significant ( P=0.03 ) . The study suggests that the relation between folate and pterins is altered in the depressed elderly
Conclusion : Low folate and B12 serum levels seem to be associated with  depression in the aged .
Objectives : To systematic ally review and meta-analyse existing evidence on the association between folate/B12 , and depression among the aged people .