If you want to conjure a new thought in your mind, you have to force yourself to stop ruminating on old thoughts. The insight could help with the treatment of PTSD and other disorders associated with rumination.
Researchers have uncovered the neural mechanism underlying rumination. The study reports when rumination occurs, coupling between the core and medial temporal lobe subsystems of the default mode network becomes elevated, while coupling between the core and dorsomedial prefrontal cortex decreases.
Repetitive negative thinking (RNT) in those aged over 55 is associated with an increased risk of cognitive decline and deposition of proteins associated with Alzheimer's disease. People who exhibited higher levels of RNT experienced more cognitive and memory problems over four years. They were more likely to have both amyloid-beta and tau protein deposits throughout the brain.