Physiological profiles of the 5 behaviourally-discriminated clusters.

The mean plasmatic or spinal concentrations (± standard error means) per cluster are reported below for the following measured variables: adrenocorticotropic hormone (ACTH); cortisol; serotonin (5-HT); 5-hydroxyindoleacetic acid (5-HIAA); dopamine (DA); homovanillic acid (HVA); 3,4-Dihydroxyphenylacetic acid (DOPAC); and norepinephrine (NE). No statistical difference was found (see Table S1 for full Kruskal-Wallis statistics).