Antidepressive Effect of Pyridoxine (Vitamin B6) in Neuroleptic-Treated Schizophrenic Patients with Co-Morbid Minor Depression - Preliminary Open-Label Trial
Roni Shiloh1, Abraham Weizman1, Nechama Weizer1, Pnina Dorfman-Etrog1, Hanan Munitz1
1Geha Psychiatric Hospital, Felsenstein Medical Research Center, Rabin Medical Center, Beilinson Campus, Petah Tikva; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
Background: Minor depression is reported in 20-60% of schizophrenic patients during various stages of their disorders; impairing patients' compliance, response to treatment and worsening their overall prognosis. Various anti-depressive treatments have been proposed for such cases but response rates are usually poor. Pyridoxine (Vitamin B6) in essential for the proper metabolism of various neurotransmitters that are considered relevant to the pathophysiology of depression and/or schizophrenia and it has been reported beneficial in ameliorating depressive symptoms as part of major depression, premenstrual syndrome or 'Chinese restaurant syndrome'. We hypothesized that addition of pyridoxine to on-going neuroleptic treatment could improve minor depression in schizophrenic patients.
Method: Nine schizophrenic patients with co-morbid minor depression participated in this study. All participants had a stable unchanged clinical state (changes in Brief Psychiatric Rating Scale (BPRS). Scale for the Assessment of Positive Symptoms (SAPS), and Scale for the Assessment of Negative symptoms (SANS) scores <5%) and all were maintained on unchanged doses of anti-psychotic drugs for at least 4 consecutive weeks prior to initiation of the study.
Participants received, open-label, pyridoxine 150 mg/day in addition to their anti-psychotic treatment for 4 consecutive weeks. Mental status was evaluated before, during, and at the end of 4 weeks of pyridoxine administration using the BPRS, SAPS, SANS and HAM-D.
Results: Two of the nine patients (22%), characterized by higher initial HAM-D and SANS scores, and by older age and longer duration of illness, experienced marked improvements in depressive symptoms (23% and 28% decrease in HAM-D scores) following 4 weeks of pyridoxine administration. In one of these two, the improvement in depressive symptoms was accompanied by a parallel decrease in SANS Scores.
Conclusion: A subgroup of schizophrenic patients with co-morbid minor depression may benefit from pyridoxine addition to their on-going anti-psychotic treatment.