Increased sister chromatid exchange and chromosomal aberration frequencies in psychiatric patients receiving psychopharmacological therapy.

Combinations of various psychotropic drugs are often used, sometimes for long periods, in the treatment of various forms of psychiatric disorders. This paper evaluates the cytogenetic consequences of daily exposure to polytherapy with antianxiety, antipsychotic and antimaniacal drugs by determining chromosomal aberrations (CA) and sister chromatid exchange (SCE) in peripheral blood samples. The study was performed with a group of 36 psychiatric patients: 18 receiving long-term treatment with lithium carbonate, combined with benzodiazepines (BD) and antipsychotic agents (Group A) and 18 treated with BD and antipsychotics (Group B). Among the latter, 7 patients had only been treated for 1 month (Group B1). The results reveal a significant increase (p<0.01) in cells with aberrations in the two groups of patients (A,B) compared to controls. Moreover, complex aberrations (dicentrics, rearrangements, chromatid exchanges) had a frequency of 0.63% in patients receiving long-term treatment compared to 0.11% in controls, corresponding to the general spontaneous rate. The mean frequency of SCE/cell and the percentage of cells with a high frequency of exchanges (HFC) also showed a highly significant difference compared to controls in both Group A and Group B. Group B1 (patients who only commenced treatment 1 month earlier) did not differ from the control group with regard to the frequency and type of chromosomal aberration or in relation to the mean frequency of SCE/cell. No significant differences were detected between Groups A and B both of which showed similar frequencies of cells with aberrations, SCE/cell and HFC. No correlations were observed in Group A between lithemia and the biological markers studied.