Youth GEMS seeks to improve our understanding of how mental health problems evolve from adolescence to adulthood. An important group we need to better understand is young people who are hospitalised in adolescence for mental health problems.

Research shows that this group is at high risk of developing schizophrenia and related psychotic disorders when followed to adulthood. But can we identify young people at risk of schizophrenia while still in adolescence?

This study tested whether psychotic symptoms, such as hearing voices or having unusual beliefs, helped to predict which adolescent inpatients would go on to develop schizophrenia.

What did the study look into?

The study followed 404 adolescents, aged 13–17, who were admitted to a regional psychiatric hospital for non-psychotic mental health conditions between 2001 and 2006. Psychotic symptoms, like hearing or seeing things that weren’t there, were assessed using a clinical interview.

Health records from national registers were used to track psychiatric diagnoses, including schizophrenia-spectrum disorders, for up to 22 years after their hospital admission. We assessed whether psychotic symptoms in adolescence predicted which individuals would go on to develop schizophrenia-spectrum disorders.

What were the main findings?

About one in four teens who were hospitalised for mental health problems went on to be diagnosed with a schizophrenia-spectrum disorder during the follow up period. That’s a really high risk! But did psychotic symptoms help to predict who would develop these disorders?

Contrary to expectations, “subthreshold” (or less severe) psychotic symptoms in adolescence did not predict who would go on to develop schizophrenia-spectrum disorders – young people who had these subthreshold symptoms had the same risk of schizophrenia as young people who did not have any psychotic symptoms.

More severe (“full-threshold”) psychotic symptoms, on the other hand, were associated with an increased risk of schizophrenia-spectrum disorders. At the same time, of all the cases of schizophrenia diagnosed in this group during the follow up period, only a small proportion (<20%) were in the young people who had severe or full-threshold psychotic symptoms in adolescence.

That means that more than 80% of schizophrenia cases would have been missed if we focused just on individuals with threshold psychotic symptoms.

What are the implications of the study?

This research shows the importance of better understanding the mental health trajectories of teens who are admitted to psychiatric hospitals. This group is at high risk of developing schizophrenia later in life – which means we need to be able to identify who, within this clinical population, is most at risk.

We found that information on psychotic symptoms, contrary to expectations, had limited utility for predicting which young people would go on to develop schizophrenia. This points to the need for research to investigate factors that might do a better job at predicting risk for later schizophrenia in this clinical population – and research on how we can reduce this risk.

Read the full study 👉

Do psychotic symptoms predict future psychotic disorders in adolescent psychiatry inpatients? A 17-year cohort study | Psychological Medicine | Cambridge Core