Systematic epidemiological and clinical comparisons across all 12 DSM-IV psychotic diagnoses in the Cavan–Monaghan First Episode Psychosis Study (CAMFEPS)

Abstract

Background Research on psychotic illness is loosening emphasis on diagnostic stringency in favour of including a more dimensionally based conceptualization of psychopathology and pathobiology. However, to clarify these notions requires investigation of the full scope of psychotic diagnoses. Methods The Cavan–Monaghan First Episode Psychosis Study ascertained cases of first episode psychosis across all 12 DSM-IV psychotic diagnoses via all routes to care: public, private or forensic; home-based, outpatient or inpatient. There was no arbitrary upper age cut-off and minimal impact of factors associated with variations in social milieu, ethnicity or urbanicity. Cases were evaluated epidemiologically and assessed for psychopathology, neuropsychology, neurology, antecedent factors, insight and quality of life. Results Among 432 cases, the annual incidence of any DSM-IV psychotic diagnosis was 34.1/100 000 of population and encompassed functional psychotic diagnoses, substance-induced psychopathology and psychopathology due to general medical conditions, through to psychotic illness that defied contemporary diagnostic algorithms. These 12 DSM-IV diagnostic categories, including psychotic disorder not otherwise specified, showed clinical profiles that were consistently more similar than distinct. Conclusions There are considerable similarities and overlaps across a broad range of diagnostic categories in the absence of robust discontinuities between them. Thus, psychotic illness may be of such continuity that it cannot be fully captured by operational diagnostic algorithms that, at least in part, assume discontinuities. This may reflect the impact of diverse factors each of which acts on one or more overlapping components of a common, dysfunctional neuronal network implicated in the pathobiology of psychotic illness.

Carepath for overcoming psychosis early (COPE): first 5 years of clinical operation and prospective research in the Cavan–Monaghan early intervention service

“…As expected in the absence of any arbitrary diagnostic restriction or upper age cut-off, the epidemiology of inceptions into COPE was generally similar to that of FEP in CAMFEPS (Nkire et al 2021b): diagnostic diversity and overall male preponderance that was more marked for SZ and particularly SIP and less evident for non-schizophrenia spectrum diagnoses; yet the most populous functional FEP diagnoses (SZ, BD, and MDDP) were each evident in both sexes from the Positive and general PANSS symptoms for inceptions into COPE did not differ between diagnoses; PANSS negative symptoms were lower in BD than in SZ, as noted in CAMFEPS (Nkire et al 2021b). COPE utilised also the SAPS, SANS, YMRS, and CDSS that confirmed an indistinguishable level of positive symptoms across the diagnoses and extended the lower level of negative symptoms in BD also to MDDP, SIP, and PGMC.…”

“…This followed previously described procedures (Nkire et al 2021a(Nkire et al , 2021b. Rate of inception into COPE is expressed as the annual number of cases per 100,000 of population aged ≥15 years (2011 census), with 95% confidence intervals (CI) for rates and rate ratios (RR).…”

“…Training of each COPE registrar took place before and during the early course of replacing their predecessor in assessment of FEP cases. Following referral for initial clinical evaluation and intervention, subjects incepted into COPE entered formal assessments as soon as was practicable using first the Structured Clinical Interview for DSM-IV Axis I Disorders (First et al 2002); at 6 months thereafter, all clinical information, to include case notes and discussions with treating teams, were reviewed to confirm or update the initial DSM-IV diagnosis as more stable and representative (Baldwin et al 2005; Nkire et al 2021 b ). Then, the instruments indicated below were applied.…”

“…As part of the development process each General Practitioner (GP) in counties Cavan and Monaghan was invited to participate in a study to evaluate their baseline knowledge of and attitudes to psychotic illness, followed by delivery of an education programme to increase awareness and encourage rapid referral of psychosis (Nkire et al 2015). The last of 432 subjects was incepted into CAMFEPS in April 2010 (Nkire et al 2021 b ) under the care of CMMHS. Progressively, through to December 2011, 33 individuals with newly presenting FEP were incepted into the prototype COPE model and, following refinements, in January 2012 the COPE model was launched by CMMHS as its EIS for FEP.…”

“…To: (i) document the development and operation of this rural EIS; and (ii) compare clinical characteristics across diagnoses to address enduring controversies regarding the extent to which boundaries between psychotic diagnoses are arbitrary and porous in the face of continuously distributed dimensions of psychopathology (Guloksuz & van Os, 2018; Nkire et al 2021 b ).…”