Symptoms of anxiety and depression were measured by 13 out of 14 items from the Hospital Anxiety and Depression Scale [52] and the seven-item CONOR Mental Health Index [53]. The Cronbach's alpha for a global summative mental health indicator, including nine anxiety items and eleven depression items was 0.91 for mothers and 0.90 for fathers. The top 10% of mothers and fathers were coded as mentally distressed. On average, distressed mothers and fathers scored 2.44 and 2.49 standard deviations above the mean of parents who were not categorized as mentally distressed.
