The Dutch Protocol Is Published

In November 2006, the European Journal of Endocrinology published the article that fully described the Amsterdam treatment model for young people. The authors were pediatric endocrinologist Henriette Delemarre-van de Waal and psychologist Peggy Cohen-Kettenis. The model became known internationally as the Dutch Protocol.

The Steps

The protocol consists of three stages. From around age twelve, once puberty has begun, a young person may receive puberty blockers. From age sixteen, sex hormones are prescribed, and from age eighteen, surgery is an option. The blockers were described as a reversible step that gives young people time to think.

The Requirements

Not every young person was eligible. The gender dysphoria had to have been present since early childhood and to have intensified during puberty. There could be no serious psychological problems that might cloud the diagnosis, and the parents had to support the treatment. Each step was preceded by a psychological assessment.

The Evidence

The article described the approach and the initial experiences, but did not yet contain long-term outcomes. Those followed in the 2011 and 2014 studies; see the first outcome studies. The first description of a patient dates back to 1998; see the first publication on puberty suppression.

Why Twelve, Sixteen and Eighteen

The age thresholds correspond to Dutch law. Under the Medical Treatment Contracts Act, children from the age of twelve make decisions about medical treatment together with their parents, and from the age of sixteen they decide independently. At eighteen, a person becomes an adult. The authors linked three types of intervention to these ages. They described puberty blockers as fully reversible: anyone who stops taking them will still go through puberty. Sex hormones are partially reversible, because features such as a lower voice or breast development remain. Surgeries are irreversible. The more invasive the step, the older the young person had to be.

What the Article Said About Risks

The authors themselves identified several uncertainties. During suppression, bone density increases less than it does in peers, and it was not known whether this would later be fully made up. The effects on brain development were also unknown. Young people who start early in puberty and then continue with hormones will not become fertile in their birth sex. In boys, the genitals also remain small, which makes later surgery more difficult. The authors believed that these disadvantages were outweighed by the benefit of sparing the young person an unwanted puberty.

The Publication Itself

The article appeared in a supplement to the journal, alongside contributions to a symposium on pediatric endocrinology. The symposium was funded by Ferring, the manufacturer of the puberty blocker triptorelin. Critics such as British sociologist Michael Biggs point to this when questioning the independence of the early research. The Amsterdam researchers maintain that the manufacturer had no influence over the content.

Significance

Until 2006, the Amsterdam approach was primarily known among professionals who visited the clinic or heard the researchers speak at conferences. The article made it possible for the first time to follow the approach in detail, including dosages, monitoring and criteria.

This publication gave clinics in other countries a fully developed example to follow. Within a few years, the model was adopted in countries including the United States, the United Kingdom and Scandinavia, and in 2009 it was incorporated into an international guideline. The strict requirements of the original protocol were not maintained everywhere. A critical review of the research since then can be found in three decades of research into the Dutch Protocol. The entire development, from the first case to the Health Council's advice, is described on transtijd.nl in the history of the Dutch Protocol.