PURPOSE Some drugs have anticholinergic activity and can cause peripheral or central side effects. Several scales exist to evaluate the potential anticholinergic effect of prescribed drugs but: (i) they are validated in the elderly and mainly assess the cognitive side effect of treatments; (ii) they do not concern some of the drugs frequently used in clinical psychiatry in France. The aim of our study is to develop a new scale, the anticholinergic impregnation scale (AIS), with drugs used in France and based on an assessment of the drugs used against peripheral anticholinergic adverse effects. METHODS We assigned a score, ranging from 1 to 3, to a list of 128 drugs with a consensus approach obtained via literature data and expert opinions. We collected data from 7278 prescriptions in 34 French psychiatric facilities: age, sex, atropinic drugs, laxatives and treatments of xerophthalmia and xerostomia, in order to evaluate the association between AIS score and the prescription of drugs aiming to reduce peripheral anticholinergic side effects. RESULTS The most frequently prescribed drugs were cyamemazine (n=1429; 20%) and tropatepine (n=1403; 19%), two drugs marketed almost exclusively in France and with a score of 3. The frequency of patients with a high AIS score, greater than 5, was significantly higher in patients who received laxatives and treatments of xerostomia. AIS score represents the first validated solution to evaluate anticholinergic load in psychiatry settings in France. CONCLUSION The anticholinergic problem remains underevaluated in mental health settings. In order to rule out the confounding factor of mental disease, assessment of peripheral side effects can be considered more objective than the evaluation of cognitive function in psychiatric patients. Building scales appropriate for each state also appear essential to obtain an useful and effective tool in clinical practice.