Obsessive Compulsive Disorder due to B12 Deficiency: Justification Required.

Sir,

By reporting a case of obsessive compulsive disorder (OCD) as early manifestation of B12 deficiency, Valizadeh and Valizadeh[1] made a commendable effort of highlighting an important issue. Vitamin B12 deficiency is a commonly overlooked cause of psychiatric and even some neurological illnesses. Common neuropsychiatric illnesses associated with B12 deficiency are dementia, neuropathies, depression, and irritability. Authors concluded that OCD was an early manifestation of B12 deficiency. However, making this report more informative could have made it a better document in favour of the finding.

First, in Case History, authors did not mention details of OCD like symptomatology, course, and severity. Information of dose, duration, response, and compliance of therapeutic agents like fluoxetine, ferrous sulfate and inderal is also lacking.

Authors did not try to explore the reason for a significant difference in lab values in just 5-month interval. Further no inference can be made about B12 levels in these 5 months. Probably there was no difference in B12 levels as body stores of B12 are sufficient for 3-4 years if supplies are completely cut off.[2]

Author's explanation for normocytic anemia is also difficult to understand, as in an anemic patient with severe deficiency of iron and cobalmin, blood picture will be microcytic, dimorphic or may be macrocytic, but not normocytic. Effects of iron and cobalamin deficiency are not mutually nullifying.

In the Result section, authors gave conclusion without actually giving results and their interpretation. They did not even mention improvement in OCD. Duration and dose of B12 and iron replacement, time frame and level of improvement, concurrent medicine use or reason for not using, duration of follow-up, reason for ruling out placebo effect, and ruling out spontaneous remission are other important issues which need answers.

Without considering these factors in this case, OCD should not be attributed to B12 deficiency, as it is a rare event and only one case has yet been reported.[3]

It is possible that B12 deficiency was a consequence rather than cause of OCD as abnormally low levels of serum vitamin B12 can be observed in 20% of OCD patients.[4] This is further supported by the perception that vitamin B12-associated cognitive changes are usually responsive to B12 within 12 months, as damage may become irreversible after longer durations.[5]

Overall it is difficult to conclude from this report that patient's OCD for last 11 years was an early manifestation of B12 deficiency because many essential data for validation of a new cause effect relationship are lacking.