Abstract
Adolescent depression is a common and serious mental disorder with unique characteristics that are distinct from adult depression. The adult non-human primate stress-induced model of depressive-like behavior is an excellent model for the study of mechanisms; however, an adolescent nonhuman primate model is still lacking. Ten male adolescent cynomolgus monkeys were divided into a chronic unpredictable mild stress (CUMS, n = 5) group and a control (CON, n = 5) group by age and weight-matched pairs. The CUMS group was exposed to multiple unpredictable mild stressors for five cycles over 55 days. At baseline, there were no differences between CUMS and CON groups. At endpoint, the CUMS group demonstrated significantly higher depressive-like behavior (huddle posture), and significantly lower locomotion compared with the CON group. Furthermore, depressive-like behavior increased from baseline to endpoint in the CUMS group, but not changed in the CON group. In the attempt for apple test, the CUMS group made significantly fewer attempts for the apple than the CON group. In the human intruder test, the CUMS group showed significantly higher anxiety-like behaviors in the stare phase than the CON group. Hair cortisol level was significantly higher in the CUMS group than the CON group at endpoint, and was also elevated from baseline to endpoint. Metabolic profiling of plasma at endpoint identified alterations in metabolite pathways which overlapped with those of adolescent depression patients. CUMS can induce depressive-like and anxiety-like behaviors, hypercortisolemia, and metabolic perturbations in adolescent cynomolgus monkeys. This is a promising model to study the mechanisms underlying adolescent depression.
Highlights
Major depressive disorder (MDD) in adolescents is a growing public health concern worldwide, with an estimated point prevalence of about 7.1%1
Behavior changes between chronic unpredictable mild stress (CUMS) group and CON group The results of huddle posture, locomotion, sucrose preference test (SPT), and body weight are shown in Fig. 2 and the detail of all the observed behaviors in Supplementary Table S6
At baseline and at the end of three stress cycles, there were no significant differences in behavior, body weight, or the SPT between CUMS group and CON group
Summary
Major depressive disorder (MDD) in adolescents is a growing public health concern worldwide, with an estimated point prevalence of about 7.1%1. The course of MDD in adolescents is often characterized by undifferentiated symptoms, frequent recurrence, protracted episodes and comorbid psychiatric disorders[2]. The first episode of depression commonly starts in adolescence, and earlier onset is related to greater risk for recurrence[3]. Suicide is the third leading cause of death in adolescents; and among depressed youth, 29% experience suicidal thoughts and 11% attempt suicide[4]. The underlying molecular mechanisms of MDD in adolescents appear complex and are poorly understood. Several studies showed that the pathophysiology, neurobiological mechanisms, and treatment response of adolescent depression diverges from adult depression[5,6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
