By Emma Young
The number of people referred in the UK to mental health services for a suspected first ever episode of psychosis rose by nearly a third between April 2019 and April 2021. The stresses of COVID-19 have been blamed. Ideally, these people would have been identified as being at-risk before they first experienced the hallucinations and/or delusions that characterise the condition. That’s because early treatment can work to delay or even prevent a first episode from occurring.
Research has revealed a suite of symptoms that can occur in this preceding period. These include odd or eccentric behaviours and ideas, unusual perceptual experiences, and suspiciousness — as well as hallucinations and delusions, but not at the level required for a diagnosis of psychosis. Non-psychotic early symptoms have been identified, too, such as anxiety, self-harm, sleep disturbance, depression and memory problems. Now a new paper in Psychological Medicine reveals which early symptoms, exactly, are associated with a faster than average progression to a first episode of psychosis — and also more symptoms later — and which are not.
Vincent Paquin at the Douglas Mental Health University Institute in Canada led a study of 390 patients aged between 14 and 35 who attended a prevention and early intervention program for psychosis. Based on interviews with the patients themselves and also family members, the team identified the occurrence and timing of 27 psychosis-linked symptoms as well as the date of each patient’s first episode diagnosis.
The median time between the first symptom (of any kind) occurring and a first episode was 3.83 years. The team did find some age-related effects, however. For example, when odd/eccentric behaviours or social withdrawal were the first symptom and they appeared after the age of 17 or 18, this was associated with a shorter time to a first episode.
But one first symptom in particular stood out as being related to a faster progression; not delusions, or hallucinations, as might perhaps have been suspected — but suspiciousness.
Why might this be? “Suspiciousness implies a cognitive interpretation of the environment as being hostile, which may make a stronger building block for illness progression, potentially through the emergence of anxiety, delusions and greater fear from hallucinations,” the researchers write. Perceptual disturbances did not emerge as being informative perhaps because they are relatively frequent in the general population, they add.
The team also found that a younger age of onset of suspiciousness was associated with more symptoms later. “Suspiciousness emerging before adolescence could be a stronger risk factor for poorer social adjustment, eg bullying, aggression,” the team writes. It might even start a vicious cycle of ever worsening behaviour and stress exposure, and poorer social perceptions, with psychopathology the end result.
A few links with non-psychotic symptoms also emerged. For example, sleep disturbance as a first symptom was associated with the development of more symptoms later on. There were also some links between self-harm, depression and anxiety and a slower progression to a first episode diagnosis. However, earlier work has found that a slower progression is associated with a poorer long-term outcome, the team notes. So knowing which first symptoms are linked to a slower progression is important, too.
The researchers themselves stress that this work was “exploratory”, and much more work is needed to explore the links identified here. In principle, though, “simple associations between early symptoms and the rapidity of illness progression can help tailor the intensity and timing of early interventions in at-risk individuals,” they conclude.
Perhaps examining the symptoms of other mental health conditions individually, rather than lumping them together, could help fine-tune early interventions for other illnesses, too.