Controlling for severity (with external measure)
If you want to compare the networks of groups, which differ in sum score of those variables, you can control for severity by partialling out an external measure of severity. Here you can find a pdf file with explanations and example code to do this in R. This is what we did in this paper (van Borkulo et al., 2015).
Simulation code to assess performance of the network comparison test (NCT)
The validation study to assess the performance of NCT was run on The LISA System. This system is a cluster computer consisting of several hundreds of multi-core nodes. Consequently, the R code of the validation study was divided into smaller parts. Here, you can find one part as an example. If you are interested in other parts, you can email me (firstname.lastname@example.org).