Psychopharmacology of maternal separation anxiety in vervet monkeys.

Maternal separation in non-human primates has been proposed as a model of early adversity. The symptoms of separation anxiety were studied in vervet monkeys, during the weaning period, when psychotropic medications were administered. The control group received a normal diet and treatment groups received citalopram, reboxetine or lamotrigine in their food daily. Treatment was given for 7 weeks starting 1 month prior to weaning. Behavior was recorded twice weekly for 8 weeks, and was rated for anxiety and depression. Cerebrospinal fluid was collected at the beginning and end of the trial and analyzed for monoamines and metabolites using High Performance Liquid Chromatography. Citalopram pretreatment prevented the reduction of affiliation behavior and reduced stereotypies after weaning, and both citalopram and reboxetine abolished the increase in activity seen in control monkeys after weaning, but no statistically significant differences were found between groups. Citalopram pretreatment also significantly increased noradrenaline and 5-hydroxyindolacetic acid (5-HIAA) levels and reboxetine significantly decreased dopamine levels over time. The 5-HIAA levels of reboxetine and lamotrigine treated monkeys were significantly lower than that of the control group at the end of the trial. Although limited by a small sample size, this study demonstrates the possibility of investigating the psychopharmacology of early adversity in a non-human primate model.