The regression coefficient was significantly negative, indicating that mean component score was significantly lower in patients than in controls
Two researchers independently completed a risk of bias assessment
Additional analysis revealed that patients with very low LAC exhibited more severe depression and were more likely to develop MDD early in life
A more in-depth analysis of the effect of oxygen levels permitted conditions to be optimized [63, 64] and showed that -butyrobetaine production was dramatically decreased when the biotransformation was performed under aerobic conditions as a consequence of the inhibition of crotonobetaine reductase by oxygen [14, 16, 63, 65]
Peer review Peer review information Nature Metabolism thanks Alice Adriaenssens, Nigel Irwin and the other, anonymous, reviewer(s) for their contribution to the peer review of this work