HTR4 and insomnia: In an exploratory post hoc network analysis of vegetative symptoms (gastrointestinal symptoms, weight loss and insomnia), sex hormones and neostriatal 5-HT4R BPND in depressed men, we observed positive associations between vegetative symptoms and testosterone, testosterone and estradiol, and estradiol and 5-HT4R (Supplementary Fig. 4).