Few studies have evaluated the development in the use of antipsychotic medication and psychotic symptoms in patients with first-episode psychosis on a long-term basis. Our objective was to investigate how psychotic symptoms and the use of antipsychotic medication changed over a 10-year period in a cohort of patients with first-episode psychosis.

The study is a longitudinal prospective cohort study over 10 years with follow-ups at years 1, 2, 5 and 10. A total of 496 patients with first-episode psychosis were included in a multi-centre study initiated between 1998 and 2000 in Copenhagen and Aarhus, Denmark.

At all follow-ups, a large proportion (20–30%) of patients had remission of psychotic symptoms without use of antipsychotic medication at the time of the follow-up. Patients who were in this group at the 5-year follow-up had an 87% [95% confidence interval (CI) 77–96%] chance of being in the same group at the 10-year follow-up. This stability was also the case for patients who had psychotic symptoms and were treated with antipsychotic medication at year 5, where there was a 67% (95% CI 56–78%) probability of being in this group at the consecutive follow-up.

A large group of patients with psychotic illness were in remission without the use of antipsychotic medication, peaking at year 10. Overall there was a large degree of stability in disease courses over the 10-year period. These results suggest that the long-term outcome of psychotic illness is heterogeneous and further investigation on a more individualized approach to long-term treatment is needed.