This study addresses a complicated question- whether individuals living neighbourhoods which are isolated in terms of their socio-economic status relative to their immediate neighbourhood 'neighbours' have higher rates of treated psychiatric conditions. The question is embedded in a large body of previous research and uses, to my knowledge, a relatively novel methodology to characterize socio-spatial relative deprivation. Overall, I believe that the authors present a well argued, nicely structured report of a topic which is complex conceptually, the technical derivation of the isolation index and the analysis of findings. From this standpoint I believe that it merits publication.

I have two small revisions which are contingent on whether I have understood the text correctly:

My understanding of the outcome is that it is counts at the MB level and that the regression model is therefore an ecological analysis. It would be best if this could be reflected in the title of the paper as ecological analyses are subject to certain well known limitations such as the ecological fallacy.

My only concern is that the independent association between isolation and health is not fully tested in the regression model. The analysis is (I think) restricted to the 33% most deprived areas.Could the authors also present results adjusted for the deprivation score entered as a continuous variable. This would clarify to me that the findings are definitively due to relative as opposed to 'absolute' deprivation.