Since much of hard/metal/heavy rock tends to depress the mind, maybe you are just now becoming aware of this and are thinking it's fatigue. 20 years ago a friend saw two therapists because of depression. Both recommended he change types of music since he mostly listened to metal and hard rock. My friend was told this type of music causes central nervous system irritation. One also told him to have his work desk moved near a window so florescent lighting was reduced. Claimed flor. lighting also causes irritation. I turned him on to Hendrix and Coltrane and he stopped digesting AC/DC, Def Lepard et al on a daily basis (and going to rock bars and concerts). He got better pretty quickly but I have no idea if he got his desk moved.
Certainly not a scientific study, just a single incident.
Certainly not a scientific study, just a single incident.