Determine levels of folic acid and vitamin B12 in a sample of depressed patients in the first visit to mental health center.

Demonstrate a high prevalence of folate and vitamin B12 deficiency in this group of patients and the relation with the depression and treatment resistant.

The sample was all the patients with a diagnosis of unipolar depression, who were derivated by general practitioner (GP) between January and June 2009 to Vallecas Villa Mental Health Center in Madrid. The sample was 82 patients, they were between 20 and 86 years old. In 62 cases the GP derivated the patients because resistant to treatment, and in 20 cases were naive-treatment. In the first visit folate serum and vitamin B12 were measured.

69 patients present low levels of folate (84,14%), and 4 low levels of vitamin B12 (4,87%). The mean of folate was 2,2 ng/ml in low-serum folate sample and the mean of vitamin B12 was 93 pg/ml in low vitamin B2 sample. 90,80% (56) of the resistant-treatment group presents low folate serum, in the naive sample was 65% (13).

In our sample depression is associated to a very high prevalence of folate deficiency. The highest prevalence appeared in the resistant-treatment group, so it could be a factor that influence in the persistent depressive symptoms, and poor antidepressant response.