Pyridoxal-5-phosphate (P-5-P) is the active form of vitamin B6, a coenzyme involved in numerous biochemical processes, including neurotransmitter synthesis. The rationale for using P-5-P in the support or adjunctive treatment of anxiety disorders stems from its critical role in the production of neurotransmitters such as serotonin, dopamine, gamma-aminobutyric acid (GABA), and norepinephrine—all of which influence mood and anxiety levels.

Several small-scale studies and some observational data suggest that individuals with anxiety may have lower plasma levels of vitamin B6, and supplementation can correct these deficiencies. A 2018 randomized controlled trial published in "Human Psychopharmacology" found that high-dose B6 supplementation (as P-5-P) reduced self-reported anxiety symptoms in young adults, though the effect size was modest and the study sample was small. Other research has linked B6 deficiency to increased rates of mood disturbances, though these studies often do not isolate anxiety disorders specifically.

Despite these findings, robust clinical evidence supporting P-5-P supplementation as a primary or standalone treatment for anxiety disorders remains limited. Most evidence is preliminary, with a few randomized trials and several observational studies indicating a possible benefit, particularly in individuals with low baseline B6 levels. As such, P-5-P may be considered as an adjunctive support in anxiety management, but not as a first-line therapy. More high-quality, large-scale randomized controlled trials are needed to establish efficacy and optimal dosing.