Polyunsaturated fatty acid concentration predicts myelin integrity in early-phase psychosis

BACKGROUND

White matter (WM) abnormalities have been implicated in schizophrenia, yet the mechanisms underlying these abnormalities are not fully understood. Several lines of evidence suggest that polyunsaturated fatty acids (PUFAs) play a role in myelination, and there is substantial evidence documenting decreased PUFA concentrations in schizophrenia. We therefore hypothesized that lower membrane PUFA concentrations may be related to reduced WM integrity in schizophrenia and related disorders.

METHODS

In 30 male patients with a recent-onset psychotic disorder, erythrocyte membrane PUFA concentrations were assessed and diffusion tensor imaging was performed with voxelwise analysis.

RESULTS

Lower total PUFA concentration was associated with lower fractional anisotropy (FA) throughout the corpus callosum and bilateral parietal, occipital, temporal and frontal WM (P < .05, corrected). Of the individual PUFAs, lower arachidonic acid concentration, and to a lesser extent, lower nervonic acid, linoleic acid, and docosapentaenoic acid concentration were significantly associated with lower FA. PUFA concentrations were inversely associated with radial diffusivity but showed little association with axial diffusivity. Greater severity of negative symptoms was associated with lower nervonic acid concentration and lower FA values.

CONCLUSIONS

Membrane PUFA concentrations appear to be robustly related to brain WM integrity in early phase psychosis. These findings may provide a basis for studies to investigate the effects of PUFA supplementation on WM integrity and associated symptomatology in early psychosis.

Red blood cell polyunsaturated fatty acids measured in red blood cells and schizophrenia: a meta-analysis

Alterations of polyunsaturated fatty acids (PUFA) in schizophrenia have been reported, but there is substantial variation in the findings. We performed a systematic review and meta-analysis for docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), linoleic acid (LA), and arachidonic acid (AA). We identified 18 studies which compared PUFA in the erythrocyte cell membrane between patients with schizophrenia and controls. A total of 642 patients (169 were antipsychotic-naïve) and 574 controls participated in these studies. We found suggestive evidence that the levels of DPA (C22:5n3) and DHA (C22:6n3) are decreased both in patients currently being treated with antipsychotic medication and antipsychotic-naïve patients. Our findings furthermore suggest that the levels of LA (C18:2n6) are decreased in the medicated subgroup, but not in the antipsychotic-naive group. Finally, we found decreased levels of AA (C20:4n6), most convincingly in antipsychotic-naive patients. Taken together, there is substantial evidence that decreased levels of DPA (C22:5n3), DHA (C22:6n3), and AA (C20:4n6) are associated with the schizophrenia syndrome, apart from a possible influence of antipsychotic medication. Given the large heterogeneity in results, these conclusions should be interpreted cautiously.

What are the factors determining authorship and the order of the authors' names? A study among authors of the Nederlands Tijdschrift voor Geneeskunde (Dutch Journal of Medicine)

CONTEXT

Although criteria justifying authorship of scientific medical articles have been formulated, it is not well known how authorship is established in practice.

OBJECTIVES

To assess the criteria for authorship used by authors of original articles in Nederlands Tijdschrift voor Geneeskunde (NTVG, the Dutch Journal of Medicine), and to determine whether the criteria for authorship of the International Committee of Medical Journal Editors (ICMJE) are known and applied.

DESIGN

Survey questionnaire.

SETTING

Editorial office of the NTVG.

PARTICIPANTS

All 450 authors of 115 original articles published in 1995.

MAIN OUTCOME MEASURES

Author's contribution to study design, material, collection of data, statistics, and writing.

RESULTS

Of 362 forms returned, 352 could be analyzed (78.2% response rate). The 5 questions most frequently answered affirmatively were ICMJE criteria: critical reading (86.1 % of the authors), approval of the final version (84.7%), study design (74.7%), study conception (64.2%), and revision (63.4%). Authors rated their contribution 2 points higher than did their coauthors. Interestingly, 64% of the respondents met the ICMJE criteria, although 60% of the respondents did not know them.

CONCLUSION

Authorship was mostly in accordance with ICMJE criteria although many authors were not familiar with them.