Figure 1.

The prevalence rates of an intermediate variable for the diagnosis of major depressive episodes by assumed input symptom prevalence and correlations. The intermediate variable is ‘significant unintentional weight loss or gain’ and the input symptoms are ‘significant unintentional weight loss’ and ‘significant unintentional weight gain.’ The black line represents the situation where the prevalence rates of the input symptoms are the same as that of the intermediate variable. Lines above the black lines have the prevalence rates of the intermediate variable larger than those of the input symptoms. CI, confidence interval.