Article, Early Access,
Rhesus monkeys exhibiting spontaneous ritualistic behaviors resembling obsessive-compulsive disorder
Affiliations
- [1] Shanghai Ctr Brain Sci & Brain Inspired Technol, Shanghai 201602, Peoples R China [NORA names: China; Asia, East];
- [2] Shanghai Jiao Tong Univ, Sch Med, Shanghai Mental Hlth Ctr, Shanghai 200030, Peoples R China [NORA names: China; Asia, East];
- [3] Lingang Lab, Shanghai 200031, Peoples R China [NORA names: China; Asia, East];
- [4] Chinese Acad Sci, CAS Ctr Excellence Brain Sci & Intelligence Techn, State Key Lab Neurosci, Inst Neurosci, Shanghai 200031, Peoples R China [NORA names: China; Asia, East];
- [5] Chinese Acad Sci, CAS Ctr Excellence Brain Sci & Intelligence Techn, State Key Lab Neurosci, Inst Neurosci, Shanghai 200031, Peoples R China [NORA names: China; Asia, East];
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Abstract
Obsessive-compulsive disorder (OCD) is a chronic and debilitating psychiatric disorder that affects similar to 2%-3% of the population globally. Studying spontaneous OCD-like behaviors in non-human primates may improve our understanding of the disorder. In large rhesus monkey colonies, we found 10 monkeys spontaneously exhibiting persistent sequential motor behaviors (SMBs) in individual-specific sequences that were repetitive, time-consuming and stable over prolonged periods. Genetic analysis revealed severely damaging mutations in genes associated with OCD risk in humans. Brain imaging showed that monkeys with SMBs had larger gray matter (GM) volumes in the left caudate nucleus and lower fractional anisotropy of the corpus callosum. The GM volume of the left caudate nucleus correlated positively with the daily duration of SMBs. Notably, exposure to a stressor (human presence) significantly increased SMBs. In addition, fluoxetine, a serotonergic medication commonly used for OCD, decreased SMBs in these monkeys. These findings provide a novel foundation for developing better understanding and treatment of OCD.