New Irish research has found that delay in treating psychosis can worsen symptoms, functioning, and quality of life and remain evident for at least 20 years after a patient first experiences the illness.

The study, led by researchers at the DETECT Early Intervention in Psychosis Service and RCSI University of Medicine and Health Sciences, has garnered international attention and is published today in The American Journal of Psychiatry.

This longitudinal study suggests that the advantages of early detection and intervention for psychosis endure for at least 20 years. The authors found that, while associations between delayed treatment and worse long-term outcome can vary depending on what outcome is measured, they are sustained across decades in a way that could not be explained by other factors.

While the importance of early detection and treatment for physical health conditions, such as cancer and heart disease, is now seen as "conventional wisdom", this study indicates that this is also the case for the mental health condition of psychosis.

The study, one of the longest-running studies of its kind to be undertaken globally, involves 171 persons who first presented with psychosis to Cluain Mhuire Mental Health Service or St John of God Hospital in Dublin between 1995 and 1999. They were then studied again at 6 months and 4, 8, 12 and 20 years later, with participants' psychotic symptoms, functioning and quality of life assessed at each time point.

The researchers found that people with longer delays in treatment had worse outcomes 20 years later in terms of their symptoms (such as hallucinations and social withdrawal), functioning (such as employment status), and quality of life (such as having satisfying interpersonal relationships).

It is estimated that 1 out of every 100 Irish people will experience an episode of psychosis in their lifetime.

Examples of symptoms are:

• abnormal sensory experiences
• irrational beliefs and impairment in thought processes
• impairment in emotionality, motivation and sociability that can disrupt numerous day-to-day activities and relationships

This research concludes that the longer someone experiences untreated psychosis, the poorer is their outcome for at least 20 years after the initial diagnosis. It also emphasises the importance of seeking help from mental health services, often via one's GP, as soon as possible after people first experience the signs and symptoms of psychosis.

The research was conducted in the DETECT Early Intervention in Psychosis Service in collaboration with RCSI University of Medicine and Health Sciences, and was supported by the St John of God Research Foundation through funding from the Health Research Board and the Stanley Medical Research Institute, USA.

Dr Donal O'Keeffe, research psychologist at DETECT and lead author, commented: "We found that a longer delay between when a person first experiences psychosis and is treated influences the extent of their recovery in the short, medium, and long term. While psychosis typically occurs in early adulthood, it can also occur at any stage in a person's life. Therefore, everyone needs to be aware of how to identify it."

Professor Mary Clarke, consultant psychologist, Clinical Professor of Psychiatry at RCSI and senior author on the paper, said: "The results of this study highlight the importance of ensuring that those with a diagnosis of psychosis have timely access to evidence-based treatments. The findings from this study also underscore the importance of investing in research that aims to improve the outcome of psychotic illnesses."

Professor John Waddington, Emeritus Professor at RCSI and senior author on the paper, commented: "That psychotic illness shows characteristics similar to other, physical illnesses is important evidence for the value of early intervention and treatment of psychotic symptoms to improve long-term outcome. Like some physical symptoms, initial psychological symptoms can be subtle and of uncertain significance. However, it is always better that such concerns are discussed with someone such as one’s GP, rather than neglected and potentially leading to more serious illness."

Earlier findings from this study provided the rationale and evidence base to establish the first early detection and intervention service for psychosis in Ireland: DETECT (Dublin and East Treatment and Early Care Team). Today, the HSE National Clinical Programme for Early Intervention in Psychosis is in the process of being implemented across the country.