Dopaminergic system and dream recall: An MRI study in Parkinson's disease patients.
Human Brain Mapping March 1, 2016 Luigi De Gennaro, Olimpia Lanteri, Fabrizio Piras et al.
Patients with Parkinson's Disease (PD) show no substantial differences from healthy controls in sleep, dream, or neuroanatomical measures. Higher dopamine agonist dosages in PD patients are associated with qualitatively impoverished dreams—lower bizarreness and emotional load. Visual vividness of dream reports positively correlates with amygdala volume and left medial prefrontal cortex thickness, while emotional load correlates with hippocampal volume. These findings support the hypothesis that a dopamine network involving the amygdala and medial prefrontal cortex plays a key role in dream generation, though causal relations cannot be established due to limitations in using dopamine agonist dosage as a proxy for hypodopaminergic state.