Consistent with other studies in early pregnancy, symptoms of major depression were associated with both moderate and severe NVP. History of depression was considered in the analysis and found not to be a determinant of moderate and severe NVP at either Time 1 or 2 . Although the study design does not allow analysis of causation, available evidence in the literature suggests the depression associated with NVP is a direct consequence rather than a cause of NVP or HG (Tan et al., 2010).