The discrepancy in attention deficit hyperactivity disorder (ADHD) medications diffusion: 1994-2003--a global pharmaceutical data analysis.

OBJECTIVE The purpose of this paper was to examine the patterns of spending, price, and the utilization of ADHD medications during the 10-year period, from 1994 to 2003 among 4 different per capita GDP group countries. METHODS This study used the IMS Health database and included both branded and generic ADHD medications. We examined the changes in quantity and price as well as the mixed effects of these changes in the U.S.A. and 3 other groups of countries classified according to their level of per capita GDP. RESULTS During this study (1994-2003), the U.S. expenditures for ADHD medications increased 594%; sales volume rose by 80%; and price increased by 285%. In other high GDP countries, expenditures increased 493%, sales volume 328%, and price increased by 39%. In the middle GDP countries, expenditures increased 164%, sales volume 141%, and price increased by 9%. In the countries with a lower per capita GDP, expenditures increased 149%, sales volume 464%, however price decreased by 37%. CONCLUSIONS The launch of long-acting ADHD medications has dramatically increased the total medication expenditure in the U.S. as well as in other high GDP markets. In the other countries quantity was the most important growth factor.