After baseline measurements, another medical doctor, trainee in psychiatry made dose adjustments according to guidelines of the Royal Dutch Association for the Advancement of Pharmacy (KNMP) which was updated July 2013. Generally three options were available: 1. Lowering/ enhancing the dose to 50-75% of the original dose 2. Prescription of medication not being metabolized by CYP2D6 or CYP2C19 3. Stop CYP2D6 or CYP2C19 inhibiting medication.