What is a Paced Auditory Serial Addition Test?


Paced Auditory Serial Addition Test (PASAT) is a neuropsychological test used to assess capacity and rate of information processing and sustained and divided attention.


Originally the test was known as the Paced Auditory Serial Addition Task (PASAT). The subjects are given in the version used as part of the Multiple Sclerosis Functional Composite a number every 3 seconds and are asked to add the number they just heard with the number they heard before. This is a challenging task that involves working memory, attention and arithmetic capabilities. Versions with numbers presented every 2 seconds are also available. The original version presented the numbers every 2.4 seconds with 0.4 decrements for subsequent trials. The PASAT was originally developed for use in evaluating patients with head injury. The advantage in this population was supposed to be minimal practice effects. This test has been widely used in other conditions besides traumatic brain injury.

Multiple Sclerosis

It has become widely used in the testing of patients with multiple sclerosis as patients with this disease frequently have an impaired performance on this test. The PASAT was included in the Multiple Sclerosis Functional Composite as a cognitive measure. However, the use of the PASAT in clinical trials in MS it has shown to be problematic as there are significant practice effects over repeated measures; typically the effect of treatment is reflected by a larger improvement on the test compared to the control group.

Is there Evidence of Cognitive Impairment in Psychosis Risk Syndrome Children & Adolescents?

Research Paper Title

Neuropsychological profile of children and adolescents with psychosis risk syndrome: the CAPRIS study.


Neuropsychological underperformance is well described in young adults at clinical high risk for psychosis, but the literature is scarce on the cognitive profile of at-risk children and adolescents.

The aim of this study is to describe the neuropsychological profile of a child and adolescent sample of patients with psychosis risk syndrome (PRS; also known as Attenuated Psychosis Syndrome) compared to healthy controls and to analyse associations between attenuated psychotic symptoms and cognitive impairment.


Cross-sectional baseline data analysis from a longitudinal, naturalistic, case-control, two-site study is presented.

Eighty-one help-seeking subjects with PRS and 39 healthy controls (HC) aged between 10 and 17 years of age were recruited.

PRS was defined by:

  • Positive or negative attenuated symptoms;
  • Brief Limited Intermittent Psychotic Symptoms (BLIPS);
  • Genetic risk (first- or second-degree relative); or
  • Schizotypal personality disorder plus impairment in functioning.

A neuropsychological battery was administered to assess:

  • General intelligence;
  • Verbal and visual memory;
  • Visuospatial abilities;
  • Speed processing;
  • Attention; and
  • Executive functions.


The PRS group showed lower general neuropsychological performance scores at a multivariate level and lower scores than controls in general intelligence and executive functions.

Lower scores on executive function and poorer attention were associated with high scores of positive attenuated psychotic symptoms.

No association with attenuated negative symptoms was found.


This study provides evidence of cognitive impairment in PRS children and adolescents and shows a relationship between greater cognitive impairment in executive functions and attention tasks and severe attenuated positive symptoms.

However, longitudinal studies are needed to clarify the nature of cognitive impairment as a possible vulnerability marker.


Tor, J., Dolz, M., Sintes-Estevez, A., de la Serna, E., Puig, O., Muñoz-Samons, D., Pardo, M., Rodríguez-Pascual, M., Sugranyes, G., Sánchez-Gistau, V. & Baeza, I. (2020) Neuropsychological profile of children and adolescents with psychosis risk syndrome: the CAPRIS study. European Child & Adolescent Psychiatry. doi: 10.1007/s00787-019-01459-6. [Epub ahead of print].