This study examines whether an early-detection program for psychosis can shorten the time patients remain untreated after the first appearance of psychotic symptoms, and whether such a reduction improves later functioning for people with first-episode schizophrenia.

Psychosis involves symptoms such as hallucinations and delusions. When these symptoms are recognized and treatment begins, most patients improve. However, many individuals live with psychotic symptoms for months-or even longer-before receiving care. This period is known as the duration of untreated psychosis (DUP). A long DUP has repeatedly been linked to poorer long-term outcomes, but it is still unclear whether DUP itself causes worse outcomes or simply reflects different illness courses.

In Denmark, Region Zealand has implemented a large-scale early-detection effort. This includes public awareness campaigns and a specialized team that identifies people with emerging psychosis and helps them start treatment quickly. The Capital Region of Denmark provides usual care without these additional initiatives. This situation makes it possible to compare two regional systems that differ in their approach to early detection but provide the same specialized treatment once patients enter care.

The study follows a quasi-experimental design, recruiting adults (18+) who receive a first diagnosis of a schizophrenia-spectrum disorder within the OPUS early-intervention programs in the two regions. No interventions are assigned by the research team; participants receive standard clinical care. Researchers conduct interviews to establish how long psychotic symptoms were present before treatment began and to assess functioning and symptoms over a two-year follow-up period. Functioning, symptoms, cognition, and treatment factors will be examined at baseline and at follow-ups.

The study addresses three questions:

Whether early-detection efforts in Region Zealand reduce the duration of untreated psychosis compared with usual detection.

Whether a shorter duration of untreated psychosis leads to better functional and clinical outcomes fifteen months after treatment begins.

How DUP can best be defined and measured so that it reliably predicts later outcomes.

Results may provide evidence for whether early-detection services improve timely access to care and whether reducing the duration of untreated psychosis contributes to better long-term functioning. The study may also help establish clearer international standards for how DUP should be measured in both research and clinical practice.