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The prolactin (PRL) response to 0.5 mg of intravenous haloperidol (HPL) IV may be a measure of tuberoinfundibular dopaminergic activity. Our earlier reports, using multidiagnostic strategies in schizophrenia, suggested that psychoses characterized by the absence of affective syndromes (Keks et al 1990) and the presence of thought disorder and passivity delusions (Keks et al 1992) are linked to blunted PRL responses. In this paper we evaluated the relationships between basal and HPL-stimulated PRL concentrations, and a number of potentially relevant symptom measures. Basal PRL was lower in patients without a depressive syndrome and suicidal ideation. Stimulated PRL was lower in patients without neurovegetative symptoms (versus patients with neurovegetative symptoms and controls), with depression (versus patients with no depression and controls) and those with disorder of associations (versus patients without association disturbance and controls). These findings can be interpreted as indicating a link between endocrine measures of dopaminergic function and a subtype of schizophrenic psychosis characterized by the presence of thinking disturbance in the absence of depression.

Latent trait models were fitted to data for 149 schizophrenic or schizophreniform inpatients rated on the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS) using the Rasch Extended Logistic Model. It was found that a reduction in the numbers of rating categories, from six to three or four led to consistencies in response while deletion of several items led to consistent scales of symptoms that accorded with an item response characterization. Behaviours included in the final scales varied in the numbers of categories, and in the range of symptom level covered by a category. Relationships between scores representing symptoms were found to be modelled better by a factor structure that included a third overlapping 'cognitive' factor in addition to the now traditional positive and negative factors, than by the original positive and negative factors alone.

The present study investigated the factor structure of the items contained in Andreasen's scales for the assessment of positive and negative symptoms (SAPS and SANS) by use of a series of principal components analyses (PCAs) with oblique rotations of the axes. It was found that the structure could be summarized by three major components labeled negative symptoms, thought disorder, and delusions/hallucinations. Dimensionality could meaningfully be increased to five components. Negative symptoms was found to separate into two components that we labeled negative signs and social dysfunctions. The delusions/hallucinations factor could be separated into two components, delusions and hallucinations, with "loss of boundary" delusions being related to both factors. Delusions of persecution were independent of other symptoms. The thought disorder factor did not decompose meaningfully within the investigated dimensionality. A two-factor solution did not explain the correlation between symptoms adequately. The results do not support the simple dichotomy between positive and negative symptoms in psychosis, but suggest that a wider dimensional concept may be more useful in future studies.

Recently, the validity of the simple dichotomy between positive and negative symptoms in psychosis has been questioned. A newly admitted group of 114 DSM-III patients with psychotic disorder were assessed using Andreason's positive and negative symptoms scales. Multidimensional scaling, augmented by cluster analysis, was applied to the full item set of these scales and showed clearly that there are three major, independent groups of symptoms: Hallucinations/Delusions, Positive Thought Disorder and Negative Symptoms. Within the Hallucinations/Delusions and Negative Symptoms groups there was some additional structure which does not conform to the SAPS and SANS sub-scales. In particular there was considerable heterogeneity within the Hallucinations/Delusions group, and delusions of persecution may represent a fourth independent dimension of psychopathology which is under-represented in these scales.

More than a decade ago, a series of retrospective studies examined the concordance between proliferating definitions of severe psychiatric disorder. The European response has been a poly-diagnostic one, which has attempted to maintain interest in a broad range of psychiatric phenomena in the psychoses. In North America a more convergent approach has emerged, resulting in a series of operational definitions evolving from one another, and a correspondingly limited capacity to allow alternative perspectives to co-exist. The present study uses a prospective design as well as recent improvements in the clinical validity of psychopathology assessment to re-evaluate the relationships between competing concepts of psychotic illness in a broad sample (N = 176) of recent-onset psychotic patients. In the schizophrenic group, concordance was predictably highest among recent North American 'cousins', and lowest among various historical concepts. There was a moderately high concordance between selected schizoaffective and atypical psychosis definitions, indicating that this component is an important area for further studies of descriptive validity. These interrelationships may be used as a starting point to explore latent classes underlying the phenomena of functional psychosis.

Clinical experience with psychotic patients early in the course of their illness suggested that symptoms of posttraumatic stress disorder (PTSD) may not be uncommon after recovery from an acute psychotic episode. Thirty-six patients recovering from an acute psychotic episode within 2 to 3 years of onset of their illness were assessed as inpatients and followed up on two occasions during the year after discharge. The prevalence of PTSD was found to be 46% at 4 months and 35% at 11 months, measured by a questionnaire linked to DSM-III criteria. The relationships between negative symptomatology and PTSD symptoms and between depressive symptomatology and PTSD symptoms were also examined; a significant correlation was found only for the latter. The psychopathological, preventive, and therapeutic implications of these findings are discussed, and future research strategies are proposed.

Of all neuroleptic-naive, acutely psychotic subjects admitted to hospital over a 2-year period (n = 62), 27 participated in a neuroendocrine study and 35 did not participate (51% refused consent, 19% were incapable of consent and 31% started neuroleptics immediately). However, all nonparticipants agreed to psychopathological evaluation, thus allowing comparison between participants and nonparticipants. The 2 groups were similar in most respects, except that more nonparticipants were hostile. Among subjects with schizophrenia, 47% of nonparticipants had the paranoid subtype vs 8% of participants. There was also a trend towards longer illness duration in nonparticipants. These results underline the need for neurobiological studies of psychosis to consider sample bias as a confounding variable.

Prolactin (PRL) response to a single dose of intravenous haloperidol (0.5 mg) was measured as a marker of tuberoinfundibular dopamine (TIDA) activity in 24 neuroleptic-free, male, psychotic patients. The PRL responses were then correlated with psychotic symptoms measured with Andreasen's Scales for the Assessment of Positive and Negative Symptoms (SAPS, SANS). Correlation analyses revealed a significant inverse relationship between PRL response and the severity of delusional symptoms. There was no significant correlation between the symptoms of hallucinations, formal thought disorder, or global negative symptoms and PRL response to haloperidol, nor were there any significant correlations between basal PRL and symptom severity. These results suggest that among the positive and negative symptoms associated with psychoses, only delusions may be associated with TIDA overactivity.

A multidiagnostic approach was used prospectively to classify a sample of 176 psychotic patients. An excess of males was found with only one out of 11 systems of schizophrenia, the World Health Organization "flexible" system of schizophrenia, with an excess of females noted in 2 of 5 systems of schizoaffective disorder, the Kasanin schizoaffective system and the Feighner schizoaffective depressed category. Correlation matrices of the diagnostic categories were generated for men and women and multidimensional scaling was used to plot the distribution of diagnostic categories. In the male sample, patients appeared to cluster according to affective symptoms and the mood-congruence of psychotic symptoms. Four clusters were apparent, but were less evident in the female sample. This gender difference was given partial support by quantitative measures of concordance. It is suggested that women manifested a greater admixture of symptoms, especially mixed affective and psychotic symptoms, than men.

The recent explosion in knowledge in the neurosciences has heightened both the expectation of significant progress in understanding the underlying mechanisms involved in the psychoses as well as frustration over the failure of such progress to occur. As biological sophistication increases, it contrasts with the obsolescence of our nosological tools, which, through their influence upon research strategy, constitute a potential obstacle to progress. Currently dominant nosological paradigms are heavily based upon assumptions concerning the links between pathophysiology and symptoms, and between symptoms and the more distal consequences of disease. This review seeks to illustrate that the linkages between disease and its consequences are in fact much looser and more plastic than acknowledged by existing paradigms, which are constrained by tradition. Since faulty assumptions concerning these linkages are so fundamental to the current nosology, it is argued that major reform is necessary. While this can be justified on research grounds alone, there are also compelling clinical reasons why reform of this kind is important and overdue.

The Royal Park Multidiagnostic Instrument for Psychosis is a validity-oriented assessment procedure developed for the acute psychotic episode using serial interviews and multiple information sources. This article describes the development and structure of the RPMIP and reports the findings of an interrater reliability study (n = 50). In addition, results are presented from a study that examined aspects of the procedural validity of the instrument when contrasted with consensus diagnoses made by a team of clinicians applying operational criteria in a less formal way to a common sample of patients (n = 87). Finally, the role of assessment procedures of this type in research into psychiatric disorders is briefly discussed.

Haloperidol was administered IV to 46 male psychotic inpatients and 28 male control subjects. A two-way analysis of covariance, with age as the covariate, revealed that DSM-III schizophrenics (n = 27) had a lower prolactin response to haloperidol than did the controls (n = 28). There were no significant differences between the prolactin responses in schizophrenics, patients with affective disorders (n = 7), and those with other psychoses (n = 12), which included patients with paranoia, schizophreniform, schizoaffective disorder, and atypical psychoses. These findings support the proposition that tuberoinfundibular dopaminergic dysfunction may occur in certain patients with DSM-III schizophrenia.

The Royal Park Multidiagnostic Instrument for Psychosis (RPMIP) is a validity-oriented assessment procedure developed for the acute psychotic episode using serial interviews and multiple information sources to construct a data base of clinical information. A number of sets of operational criteria, including 11 definitions of schizophrenia and several concepts of atypical, schizoaffective, and affective psychoses, are simultaneously applied to the data base to produce a diagnostic profile for each patient that can be linked to other variables. This article describes the rationale for the development of the RPMIP and contrasts it with other assessment and diagnostic procedures. A companion article (Part II) presents data on interrater reliability and procedural validity, together with an account of the structure and development of the instrument.

This paper reviews recent progress in the assessment of the psychopathology of psychosis and focuses upon a number of persistent limitations. In particular the over-emphasis upon reliability at the expense of validity is highlighted and the relationship between reliability and validity is reconsidered. A number of strategies aimed at improving the validity of psychopathological measures are outlined. Proposals to deploy such variables differently in research strategies and analyses are endorsed.