"Hypovitaminosis D is frequent and associated with depressive symptoms and anxiety disorders in schizophrenia"

The paper published by Guillaume Fond and colleagues [1] concluding that: "Hypovitaminosis D is frequent and associated with depressive symptoms and anxiety disorders in schizophrenia" provides the blogging fodder today. Hypovitaminosis D is just another way of saying vitamin D deficiency (or perhaps insufficiency) and follows a number of previous research findings (see here) concluding that schizophrenia seems to be one of a number of conditions/diagnosis/labels where tested vitamin D levels show sub-optimality.

Fond report results based on their examination of the "national FondaMental Expert Center (FACE-SZ) Cohort", something that has been talked about on this blog before (see here). So: "A comprehensive 2 daylong clinical and neuropsychological battery was administered in 140 SZ subjects included between 2015 and 2017" including vitamin D testing and analyses looking for the signs and symptoms of depression and anxiety.

Results: about one in five of the study participants were in a state of hypovitaminosis D. Looking at the accumulated behavioural data - "Depressive symptoms were assessed by the Positive and Negative Syndrome Scale depressive subscore and current anxiety disorder by the Structured Clinical Interview for Mental Disorders" - I was particularly struck by the *link* between vitamin D deficiency and 'current anxiety disorder' ("aOR = 6.18 [2.15-17.75], p = 0.001"). Further: "Vitamin D supplementation has been administered during the previous 12 months in only 8.5% of the subjects but was associated with lower depressive symptoms... and lower rate of current anxiety disorder... compared to patients with hypovitaminosis D."

These are interesting results. They reiterate that a diagnosis of schizophrenia does not seem to be protective against the development of vitamin D deficiency/insufficiency. They also highlight that schizophrenia perhaps should not be considered as a stand-alone diagnosis; something that is beginning to be realised across various different behavioural labels (see here). The suggestion of an *association* between anxiety and/or depression in the context of vitamin D is also important (perhaps even relevant to other studies that have suggested a direct link between vitamin D and schizophrenia). And then there is the 'already supplemented' finding that seems to fly in the face of quite a lot of other evidence suggesting that correcting vitamin D deficiency in the context of something like depression might not be directly applicable to improvement in depressive symptoms (see here). Research questions remain but the Fond results look interesting...

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[1] Fond G. et al. Hypovitaminosis D is associated with depression and anxiety in schizophrenia: Results from the national FACE-SZ cohort. Psychiatry Res. 2018 Sep 13;270:104-110.

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