Table 2.

Altered pathways in the blood of patients with major depressive disorder.

Pathways	p valuea
Metabolic pathways identified by MetaboAnalyst
Nitrogen metabolism	<0.001
Aminoacyl-tRNA biosynthesis	<0.001
Fatty acid biosynthesis	0.001
Alanine, aspartate and glutamate metabolism	0.001
Linoleic acid metabolism	0.008
Glycine, serine and threonine metabolism	0.009
Cyanoamino acid metabolism	0.009
Cysteine and methionine metabolism	0.013
Taurine and hypotaurine metabolism	0.014
Arginine and proline metabolism	0.031
Canonical pathways identified by IPA
tRNA charging	<0.001
Glycine betaine degradation	<0.001
l-Serine degradation	<0.001
Asparagine biosynthesis I	0.003
Palmitate biosynthesis I (animals)	0.006
Superpathway of methionine degradation	0.007
Cysteine biosynthesis III (mammalia)	0.010
NAD biosynthesis II (from tryptophan)	0.021
Folate transformations I	0.021
HIF1α signaling	0.024
Asparagine degradation I	0.035
Glutamine degradation I	0.035
Pyruvate fermentation to lactate	0.047
Glycine biosynthesis III	0.047
Alanine degradation III	0.047
Alanine biosynthesis II	0.047
Myo-inositol biosynthesis	0.047
l-Cysteine degradation II	0.047
Phosphatidylethanolamine biosynthesis III	0.047
Glycine biosynthesis I	0.047

^ap values were calculated from hypergeometric tests in MetaboAnalyst, and from Fisher’s exact tests in Ingenuity pathways analysis