Early postnatal antidepressant treatment and juvenile stereotyped behaviour in rats.

The effect of antidepressants on stereotyped behaviour in rats during development was examined. Rats were injected s.c. once a day from the 6th to the 22th day after birth with 0.9% sodium chloride, with desipramine 5 mg/kg body weight, with nomifensine 10 mg/kg, or with zimelidine 25 mg/kg. Stereotyped behaviour was assessed when the rats were 1 month and 2 months of age. Desipramine intensified and prolonged apomorphine 0.5 mg/kg induced stereotyped behaviour at 1 month but not at 2 months of age. Nomifensine and zimelidine did not affect stereotyped behaviour at either 1 month or 2 months of age. Thus, 2-week treatment with desipramine during early development was shown to increase stereotyped behaviour at a juvenile age.