He actually writes they can be ‘expected’ to be the same. And he does suggest replication in other countries. If he had specified ‘western countries’ it would probably have been a bit stronger. Still, it is a reasonable assumption. Psychiatric science is published in international journals, the diagnostic systems are used internationally, american research output is immense and influence psychiatry in all western countries. Paradigms for research and dissemination works across national borders. In a sense national textbooks can reasonably be expected to be local expressions of some transnational lore.