VALIDITY OF THE SCHIZOPHRENIA DIAGNOSIS OF THE PSYCHIATRIC-ASSESSMENTSCHEDULE FOR ADULTS WITH DEVELOPMENTAL DISABILITY (PAS-ADD)

Background. First rank symptoms are central to the diagnosis of schizo phrenia, but their complexity makes it difficult to validly detect the m in people with learning disability. This report investigates ability of PAS-ADD to detect schizophrenia, validated against expert clinical opinion. Method. The sample consisted of 98 patients with learning di sability. and a key informant for each sample member. Clinical opinion s of the referring psychiatrists were sought using a symptom checklist . Reportage of remission. and the number of core schizophrenia symptom s identified were used to estimate level of symptom activity at time o f interview. Results. The proportion of schizophrenia cases detected b y PAS-ADD increases with the number of active core symptoms identified by the referrer. Where two or more core symptoms were indicated. PAS- ADD detected 71% cases. The most frequently fulfilled criterion was th ird-person auditory hallucinations. Six schizophrenia diagnoses disagr eed with the clinician, four of which were referred as being hypomania . Overall symptom frequency detected by PAS-ADD was positively correla ted with IQ. Conclusions. Results suggest there may be scope for modif ying the ICD-10 diagnostic algorithm for use with learning disability, particularly in relation to the delusions and negative symptoms crite ria.