The Schizophrenia Proneness Instrument has its origins in the basic symptom concept first described by Gerd. Basic symptoms are subtle, subclinical self-experienced disturbances in drive, stress tolerance, affect, thinking, speech, perception and motor action, which are phenomenologically clearly distinct from psychotic symptoms. They can be present before the first psychotic episode, between and after psychotic episodes, even during psychotic episodes themselves. They were thought to be the most immediate psychopathological expression of the somatic disturbance underlying the development of psychosis – thus the term ‘basic’.
Basic symptoms are phenomenologically different from mental states known to the patient/subject from what s/he considers his/her ‘normal’ self and thus are clearly distinguishable from subtle disturbances described as traits in those at genetic high-risk. In addition, basic symptoms are phenomenologically clearly distinct from attenuated or frank psychotic symptoms – employed in the ‘ultra-high risk’ (UHR) criteria of an imminent risk of first-episode psychosis – as they are not necessarily observable by others as are odd thinking and speech, negative symptoms and formal thought disorders. They are regarded as having originating in the subject, unlike schizotypal perceptual disturbances and hallucinations, and do not primarily affect thought content as do magical thinking, ideas of reference, paranoid ideation and delusions.
Frauke Schultze-Lutter, PhD, is the scientific-psychological head of the Early Recognition and Intervention Centre for mental crises (FETZ) at the Department of Psychiatry of the University of Cologne, Germany, Europe’s first early detection service starting its work in 1997. Her interest in subjective experiences in psychoses dates back to her student’s days in Göttingen where she graduated in clinical psychology with the diploma thesis on basic symptoms in persons with mental retardation, schizophrenia and both.
Jean Addington, PhD, is a Professor in the Department of Psychiatry at the University of Toronto; Canada, and the Director of the PRIME Clinic, a research clinic for individuals at risk of psychosis, at the Centre for Addiction and Mental Health in Toronto, Canada. She is currently the President of the International Early Psychosis Association.
Stephan Ruhrmann, MD, is the medical head of the FETZ and assistant medical director of the Department of Psychiatry of the University of Cologne. He had coordinated the pharmacological multi-centre early intervention trial within the German Research Network on Schizophrenia and the European Prediction of Psychosis Study (EPOS) and has special interest in the biological correlates of the prodromal phase.
Joachim Klosterkötter, Professor, MD, is the medical director of the Department of Psychiatry and dean of the Medical Faculty of the University of Cologne. As a co-author of the Bonn Scale for the Assessment of Basic Symptoms (BSABS) and with his postdoctoral lecture qualification on transition sequences from basic to psychotic symptoms, he has a long standing interest in the early detection of psychoses and is the PI of several national and international mono- and multi-centre studies on this topic.
The Schizophrenia Proneness Instrument, Adult version (SPI-A), assesses a wide range of subtle, self-experienced disturbances first described as basic symptoms. Primarily designed to support the prediction of first-episode psychosis, it also facilitates a broad range of clinical and research issues across the different states of the illness.
The SPI-A provides important insight into subclinical complaints and deficits that often precede frank psychotic episodes and maintain during remission. Hence, it mainly targets psychiatrists and psychologists with a clinical and scientific interest in psychoses but it may be relevant for other professionals, students, patients and families involved in the care of those with psychosis. Patients themselves might be supported by the SPI-A in expressing their subjective experiences that often appear to be hard to describe spontaneously.