Methods
PD, Depression
Patients received oral clonidine (75 µg twice a day, a morning and an evening) or a placebo for 8 weeks without any titration. Patients were instructed not to change their PD treatment (medications and/or DBS settings) during the study and treatment was checked at each visit. Randomisation and allocation to the trial group were carried out by a central computer system. Assignment was masked from the patients, study staff, investigators, and data analysts. The QUIP-RS was administered by a neuropsychologist specialised in PD. The neuropsychologists were trained before the beginning of the study in order to standardise, between centres, the administration of the questionnaire. When two sub-scores were equal, we the most disabling for the patient according to the neurologist was retained. Depression symptoms were assessed using the BDI II [