Abstract: Sleep/circadian timing depends on several neurotransmitter systems, including 5-HT, NE, DA, Ach, GABA, etc. These neurotransmitter systems play critical roles in mental, emotional and cognitive functions in the brain. Dysfunctions of these systems not only result in sleep disorder, but are also related to many psychiatric and neurodegenerative diseases. Sleep disruption is tightly associated with an increased susceptibility to a broad range of psychiatric and neurodegenerative diseases, such as depression and Parkinson diseases. Non-human primates, especially the rhesus monkey is an excellent biomedical model for human sleep and CNS diseases. Establishing nonhuman primates’ model of mental disorders and monitoring the sleep changes during the development of the model will help us to know more about the relationships between sleep disorder and psychiatric and neurodegenerative diseases. Sleep disorder as an early marker for psychiatric and neurodegenerative diseases would permit early intervention of these diseases and draw attention to the potential therapeutic benefits of normalizing sleep rhythms in individuals with brain pathologies.