Genotype plays role in schizophrenia response to folate

From Clinical Psychiatry News, 19 March 2013:

Folate and vitamin B12 supplements may improve the negative symptoms of schizophrenia but only in patients with a genetic variant that influences folate metabolism, a study has shown.

“Although four such variants have previously been associated with negative symptom severity, the genotype that contributed most strongly to treatment response was FOLH1 484T>C,” wrote Dr. Joshua L. Roffman, of the psychiatry department at Massachusetts General Hospital, Boston, and his colleagues.

Patients treated with folate plus vitamin B12 showed significant improvement on the Scale for the Assessment of Negative Symptoms (SANS), compared with placebo (group difference, –0.33 change in score per week; 95% confidence interval, –0.62 to –0.05), when genotype was taken into account.

Among patients homozygous for the 484T allele – a genetic variant in the folate hydrolase 1 (FOLH1) gene – the benefits of folate and vitamin B12 supplements were even greater (–0.59 change in SANS score per week; 95% CI, –0.99 to –0.18), according to results published in JAMA Psychiatry (formerly Archives of General Psychiatry) (2013 March 6 [doi: 10.1001/jamapsychiatry.2013.900]). Read more.