Basal and haloperidol-stimulated prolactin in neuroleptic-free men with schizophrenia defined by 11 diagnostic systems

Schizophrenia: comparison of 13 diagnostic systems in a cross-sectional study1

The concordance and degree of overlap between 13 diagnostic systems for schizophrenia, including the five European systems of Berner, Bleuler, Langfeldt, Pull and Schneider, were evaluated in a cross-sectional study (N = 51) taking the phase of illness (acute or residual) into account. The diagnostic assessments were processed by computer using a 183-item standardised checklist and a data-processing program in GW-Basic language. The inter-rater reliability, as assessed by Kappa coefficient, was good to excellent for each diagnostic system established by this method (K from 0.5 to 1). When comparing the concordance between pairs of 13 diagnostic systems for schizophrenia in acute and residual phase groups, results showed that only two significant relationships were not influenced by the phase of illness (Carpenter x RDC; Catego x Schneider), while 24 were. These included only two relationships in the acute group (Carpenter Catego; Carpenter Schneider) and 22 links between pairs of systems in the residual group. In the acute group, no diagnosis of schizophrenia, including duration criteria such as those of DSM III-R, Feighner, Langfeldt, Pull and RDC, was linked to other systems. In the residual group, the operational systems such as Catego, DSM III-R, Feighner, Newhaven, Pull and RDC had more than five relationships with the other systems whereas the non-operational systems of Bleuler, ICD9, Langfeldt and Schneider had less than four relationships with the others. Except Pull's criteria, the European diagnostic systems, in particular Berner's and Bleuler's, seemed to differ from the others because of the few relationships displayed. The results underline the importance of taking the phase of illness into account when comparing between studies utilizing different diagnostic systems for schizophrenia. They also show the relationships between European and international diagnostic systems, insufficiently established so far.

Prolactin and psychopathology in schizophrenia: a literature review and reappraisal

Secretion of the anterior pituitary hormone prolactin can be significantly increased by antipsychotic drugs, leading to a range of adverse effects in patients with schizophrenia. However, there is evidence from a variety of studies that prolactin may also be related to symptom profile and treatment response in these patients, and recent work has identified variations in prolactin secretion even in drug-free patients. In this paper, a selective review of all relevant studies pertaining to prolactin and schizophrenia, including challenge and provocation studies, is presented. The implications of this work are discussed critically. A tentative model, which synthesizes these findings and argues for a significant role for prolactin in the development of schizophrenia, is outlined.

Competing definitions of schizophrenia: what can be learned from polydiagnostic studies?

The contemporary diagnoses of schizophrenia (sz)-Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition(DSM-IV) and International Classification of Diseases, 10th Revision(ICD-10)-are widely considered as important scientific achievements. However, these algorithms were not a product of explicit conceptual analyses and empirical studies but defined through consensus with the purpose of improving reliability. The validity status of current definitions and of their predecessors remains unclear. The so-called "polydiagnostic approach" applies different definitions of a disorder to the same patient sample in order to compare these definitions on potential validity indicators. We reviewed 92 polydiagnostic sz studies published since the early 1970s. Different sz definitions show a considerable variation concerning frequency, concordance, reliability, outcome, and other validity measures. The DSM-IV and the ICD-10 show moderate reliability but both definitions appear weak in terms of concurrent validity, eg, with respect to an aggregation of a priori important features. The first-rank symptoms of Schneider are not associated with family history of sz or with prediction of poor outcome. The introduction of long duration criteria and exclusion of affective syndromes tend to restrict the diagnosis to chronic stable patients. Patients fulfilling the majority of definitions (core sz patients) do not seem to constitute a strongly valid subgroup but rather a severely ill subgroup. Paradoxically, it seems that a century after the introduction of the sz concept, research is still badly needed, concerning conceptual and construct validity of sz, its essential psychopathological features, and phenotypic boundaries.

Changes in central serotonergic function as a correlate of duration of illness in paranoid schizophrenia

There is evidence that the duration of untreated psychosis may affect both the course and outcome of treatment in schizophrenic patients. In the present study, we used neuroendocrine probes to test the hypothesis that untreated psychosis may induce time-dependent changes in central serotonergic and dopaminergic neurotransmission. Prolactin responses to the administration of clomipramine (i.v.) and haloperidol (i.m.) were measured in healthy control subjects and in 16 never-treated male patients with DSM-IV diagnoses of schizophreniform or schizophrenic disorders of paranoid subtype, both before and after 5 weeks of treatment with haloperidol. In the drug-free state, schizophrenic patients exhibited significantly increased prolactin responses to clomipramine administration compared with both the healthy control subjects and the schizophreniform patients. Maximum prolactin responses to clomipramine in the total group of patients were positively correlated with the duration of psychotic illness and negatively correlated with changes in Positive and Negative Syndrome Scale (PANSS) total, negative symptoms and general psychopathology scores after 5 weeks of treatment with haloperidol. Prolactin responses to haloperidol challenge in the drug-free state were lower in the schizophreniform group than in the control and the schizophrenic groups, but the differences did not reach statistical significance. The results provide evidence that the persistence of psychotic psychopathology induces secondary neuroadaptive effects, which seem to involve changes in central serotonergic function.

Basal and haloperidol-stimulated prolactin and symptoms of nonaffective and affective psychoses in neuroleptic-free men

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.

Growth hormone response to clonidine in neuroleptic-free patients with multidagnostically defined schizophrenia

The role of alpha 2-adrenergic receptor sensitivity in schizophrenia was examined by measuring growth hormone (GH) response after the intravenous administration of clonidine (1.3 micrograms/kg) in 26 healthy control subjects and 26 neuroleptic-free, acutely psychotic patients with at least 1 out of 11 possible diagnoses of schizophrenia derived from a multidiagnostic psychopathological assessment. GH responses were significantly (0.01) lower than control values in schizophrenias defined by E. Bleuler, M. Bleuler, Schneider, Langfeldt, Taylor and Abrams, and Cloninger, but not in DSM-III, World Health Organization, Feighner, Kraepelian, and Research Diagnostic Criteria (RDC) schizophrenias. Eight patients with RDC schizoaffective disorder also had a blunted response. However, there were no correlations with any symptom measures. There were no differences between paranoid and nonparanoid patients, although there was a significant difference between nonparanoid patients and control subjects. These findings support the presence of noradrenergic dysfunction in some patients within the schizophrenia syndrome, possibly those whose illnesses have an affective component. The study also illustrates the need for simultaneous investigation of several different sets of diagnostic criteria for schizophrenia in neurobiological research.

The Kallmann's syndrome variant (KSV) model of the schizophrenias

The KSV model of the schizophrenias proposes that up to 70% of schizophrenics have a pathogenic allele, or abnormal expression, of the KALIG-1 gene which is located at Xp22.3. This gene encodes a nerve-cell adhesion molecule (N-CAM) like protein, and is deleted in 66% of patients with Kallmann's syndrome, anosmia with secondary hypogonadism. Although superficially distinct, the schizophrenias and Kallmann's syndrome show numerous parallel trait defects which occur with a similar sex distribution. These defects are usually more profound in Kallmann's syndrome. Occasionally, Kallmann's patients exhibit additional defects, such as ichthyosis, which are due to the further deletion or translocation of adjacent genes. Since schizophrenics exhibit virtually all known trait defects in Kallmann's except these, it suggests that the aberrant genes are defective, but not deleted in schizophrenia. It also appears that compensatory mechanisms, involving serine proteases, are active in schizophrenia, which largely preserve fertility, but at the expense of an increased vulnerability to develop a psychosis by an episodic disruption of the blood-CSF barrier. Consequently, schizophrenia is rare in Kallmann's patients, while most schizophrenics are capable of reproduction.

Multidiagnostic evaluation of prolactin response to haloperidol challenge in schizophrenia: maximal blunting in Kraepelinian patients

We have previously reported that prolactin (PRL) responses to haloperidol 0.5 mg IV were blunted in subjects characterized by several diagnostic systems of schizophrenia compared to controls (Keks et al 1990). However, an attempt to find a diagnostic system most different from controls was unsuccessful due to inherent difficulties in the statistical analysis of multidiagnostic data. In this paper we present new methodologies. A test for differences in dependent correlations demonstrated that most of the variance in stimulated PRL was accounted for by Kraepelinian, and least by Schneiderian and M. Bleulerian, schizophrenias (p < 0.001). The main symptomatic difference between nonKraepelinian and Kraepelinian patients was the presence of association disturbance and feelings of passivity. Patients with both symptoms had a lower stimulated PRL than controls. Further findings and possible implications are discussed.

Diagnostic concordance in functional psychosis revisited: a study of inter-relationships between alternative concepts of psychotic disorder

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.

Prolactin bioassay in schizophrenia before and after neuroleptics

Fifteen drug-free schizophrenic male inpatients and 14 normal control subjects were studied. The schizophrenic subjects had a significantly lower ratio of bioassay prolactin to radioimmunoassay prolactin before neuroleptic treatment than they did after treatment. The ratio was lower in the drug-free patients as compared with normal controls. These findings suggest that neuroleptic medications may alter the molecular forms of serum prolactin. The results also suggest that drug-free schizophrenic patients may have a different pattern of prolactin variants than normal subjects and that this difference could be secondary to a disordered tuberoinfundibular dopamine system or long-term effects of neuroleptic drugs.

Comparison of participants and nonparticipants in a neuroendocrine investigation of psychosis

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.

Enhanced haloperidol-induced prolactin stimulation with chronic neuroleptic treatment in the rat

Animals were treated either acutely, or chronically for 21 days, with a low dose (0.1 mg/kg) of haloperidol, then sacrificed to obtain trunk blood for radioimmunoassay of prolactin (PRL) level. PRL concentrations on day 21 of chronic treatment were greater than two-fold those produced by acute neuroleptic. Challenge with apomorphine to rats withdrawn for 48 hours revealed similar PRL reductions as a group withdrawn from chronic vehicle injections.