Psychotropic drugs are used for treatment of behavioral and psychological symptoms of dementia (BPSD) although they are associated with serious adverse drug events. Objective of our study was to investigate prevalence of psychotropic drug use one year after diagnoses of Alzheimer's disease (AD), to compare prevalence to persons without AD and to assess changes in prevalence over time. Data from the MEDALZ (Medication use and Alzheimer's disease) cohort was utilized in the study including all 69,080 community-dwelling persons with new diagnosis of AD during years 2005-2011 in Finland. Four age-, gender- and region of residence-matched persons without AD were identified for each case. Register-based data included prescription drug purchases and comorbidities from Special Reimbursement Register. Annual prevalence of psychotropic drug use one year after diagnosis was determined for each person. Psychotropic drugs were used by 53% of persons with AD compared with 33% of persons without AD during one year after diagnoses. Persons with AD were six times more likely to use antipsychotics and three times more likely to use antidepressants whereas benzodiazepine and related drug (BZDR) use was comparable between persons with and without AD. According to year of AD diagnoses during 2005-2011, antipsychotic use increased from 18% to 20% (p<0.0001) and BZDR use declined from 31% to 26% (p<0.0001) among persons with AD. Widespread utilization of psychotropic drugs was observed among persons with AD. Despite safety warnings of antipsychotic use for BPSD, antipsychotic use increased from 2005 to 2011 among newly diagnosed persons with AD in Finland.