Antidepressant drugs: prevalence, incidence and indication of use in general practice of Southern Italy during the years 2003-2004

Purpose: To estimate 1-year prevalence, 1-year incidence and indication of use of antidepressant (AD) drug treatment in general practice of Southern Italy during the years 2003-2004. Methods: Among 142,346 individuals registered in the lists of 119 general practitioners of Southern Italy, we identified users of different AD types: tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs) and other antidepressants. Annual prevalence of AD use was measured as the number of individuals receiving at least one AD prescription in the years 2003-2004, divided by the number of patients registered in the general practitioner (GP) lists. One-year incidence of AD treatment was calculated as the number of new users of AD, divided by the number of total patients free from AD prescriptions in the previous year. Results: Overall, 1-year prevalence of AD use was 5.08 (95% confidence interval (CI): 4.97-5.20) per 100 inhabitants in the year 2003, with a 20% increase in 2004 (6.00, 5.88-6.13). Prevalence of SSRI use markedly increased from 3.80 (3.73-3.90) in 2003 to 4.51 (4.40-4.61) in 2004. The incidence rates of SSRI, TCA and other antidepressant use were 2.11 (2.03-2.19), 0.38 (0.35-0.41) and 0.53 (0.49-0.57) respectively. Depressive disorders were the main indication of use of any AD user (mostly for SSRI users), followed by anxious disturbances. Conclusions: SSRIs, particularly those recently marketed, have been increasingly used during the last years, mainly to treat affective disorders.