The effect of combined treatment with risperidone and antidepressants on the MK-801-induced deficits in the social interaction test in rats.
BACKGROUND
Several clinical reports have suggested that augmentation of atypical antipsychotics' activity by antidepressants may efficiently improve the treatment of negative and some cognitive symptoms of schizophrenia.


METHODS
The aim of the present study was to investigate the effect of antidepressant mirtazapine or escitalopram and risperidone (an atypical antipsychotic), given separately or jointly, on the MK-801-induced deficits in the social interaction test in rats. Antidepressants and risperidone were given 60 and 30 min before the test, respectively. The social interaction of male Wistar rats was measured for 10 min, starting 4 h after MK-801 (0.1 mg/kg) administration.


RESULTS
In the social interaction test, MK-801-induced deficits in the parameters studied, i.e. the number of episodes and the time of interactions. Risperidone at a higher dose (0.1 mg/kg) reversed that effect. Co-treatment with an ineffective dose of risperidone (0.01 mg/kg) and mirtazapine (2.5 or 5 mg/kg) or escitalopram only at a dose of 5 mg/kg (but not 2.5 and 10 mg/kg) abolished the deficits evoked by MK-801.


CONCLUSIONS
The obtained results suggest that especially mirtazapine, and to a smaller degree escitalopram may enhance the antipsychotic-like effect of risperidone in the animal test modeling some negative symptoms of schizophrenia.
Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
Katarzyna
K
Kamińska
Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland; The Podhale State Higher Vocational School, Nowy Targ, Poland. Electronic address: rogoz@if-pan.krakow.pl.
Zofia
Z
Rogóż
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D015283:Citalopram / Q000494:pharmacology*; D016291:Dizocilpine Maleate / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D008297:Male; D008803:Mianserin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000078785:Mirtazapine; D051381:Rats; D018967:Risperidone / Q000494:pharmacology*; D012919:Social Behavior
D000928:Antidepressive Agents; D015283:Citalopram; D008803:Mianserin; D016291:Dizocilpine Maleate; D000078785:Mirtazapine; D018967:Risperidone
Antidepressants; MK-801; Rats; Risperidone; Social interaction test