Daniel Umbricht

Electrophysiological Indices of Automatic and Controlled Auditory Information Processing in First-Episode, Recent-Onset and Chronic Schizophrenia

BACKGROUNDnDeficits in amplitudes of auditory event-related potentials (ERP) indexing preattentive, automatic (mismatch negativity, MMN) and controlled, attention-dependent (N2, P3) auditory information processing have been well described in chronic schizophrenia. Normal MMN, but deficient N2 and P3 have been reported in first-episode patients. No study has investigated these ERPs concurrently in first-episode patients; thus, reported differences in MMN, N2 and P3 generation may reflect differences in patient samples rather than genuine differences in abnormal generation of these ERPs.nnnMETHODSnWe recorded MMN, N2 and P3 in 26 first-episode patients, 25 recent-onset patients within 1.5 to 5 years after first admission, 25 chronic patients and 39 healthy controls.nnnRESULTSnRecent-onset and chronic, but not first-episode patients showed reduced MMN. However, among first-episode patients those with low premorbid educational achievement demonstrated significantly reduced MMN. All patient groups showed pronounced N2 deficits and, to a variable extent, abnormalities in P3 generation.nnnCONCLUSIONSnAbnormalities in N2 and P3 generation appear to reflect premorbid neuropathology, whereas MMN deficits may index both ongoing disease processes associated with illness progression as well as premorbid neurocognitive impairment. ERPs may provide tools to assess static and progressive neuropathology in schizophrenia. These findings need confirmation in longitudinal studies.

Defining subjects at risk for psychosis : A comparison of two approaches

The ability to detect individuals at high risk for developing schizophrenia before they express the disease will lead to targeted early intervention. It has been proposed that subjects at risk share a core deficit with people who already have schizophrenia. This includes cognitive impairment, affective symptoms, social isolation and decline in social functioning. In a sample of 104 help-seeking patients from a specialised outpatient clinic we investigated how well two different sets of criteria define the at-risk group and capture this core deficit. One set of criteria is the well-established ultra high-risk model of McGlashan et al. [McGlashan 2001 (SIPS) McGlashan, T. H., Miller, T. J., Woods, S. W., et al. (2001) Structured Interview for Prodromal Syndromes (Version 3.0, unpublished manuscript). New Haven, Connecticut: PRIME Research Clinic, Yale School of Medicine.]; the other criteria were those defined by Cornblatt et al. [Cornblatt, B., Lencz, T., Smith, C.W., Correll, C.U., Auther, A., Nakayama, E., 2003. The schizophrenia prodrome revisited: a neurodevelopmental perspective. Schizophr. Bull. 29, 633-651.]. There was considerable overlap in the two sets of criteria. However, when the basic symptoms of Klosterkötter [Klosterkötter, J., Hellmich, M., Steinmeyer, E.M., Schultze-Lutter, F., 2001a. Diagnosing schizophrenia in the initial prodromal phase. Arch. Gen. Psychiatry, 58, 158-164.] were included in the McGlashan et al. model, a more narrow and homogeneous group was defined.

Ultra high-risk state for psychosis and non-transition: a systematic review

BACKGROUNDnMost effort in ultra high-risk (UHR) research has been directed at defining the clinical and neurobiological characteristics of those UHR subjects who go on to develop psychosis. The characteristics and outcome of the remaining UHR subjects have remained relatively unexplored.nnnMETHODnWe performed a systematic review of clinical UHR studies to investigate whether information was available on the characteristics and outcome of UHR subjects who did not convert to psychosis.nnnRESULTSnOf 2462 potentially relevant papers, 31 met inclusion criteria, i.e. 20 naturalistic and 11 intervention studies. On average 76% (range 46-92.6%) of the UHR patients made no transition to psychosis during follow-up (range 6 to 40 months). Nearly half of the studies provided no characteristics of those UHR subjects who did not develop psychosis. Six studies reported remission rates from initial UHR status (range 15.4% to 54.3%). Linear regression showed that more recent studies reported significantly lower transition rates as compared to earlier publications. An older mean age at baseline was associated with significant lower transition rates in publications with follow-ups exceeding 1 year.nnnCONCLUSIONSnOur review illustrates that the long-term outcome of UHR subjects that do not develop psychosis is to date under-investigated. The studies reporting remission rates suggest that UHR criteria capture a non-negligible proportion of subjects that do not convert to psychosis.

Help-seeking pathways in early psychosis

IntroductionUnderstanding the help-seeking pathways of patients with a putative risk of developing psychosis helps improving development of specialised care services. This study aimed at obtaining information about: type of health professionals contacted by patients at putative risk for psychosis on their help-seeking pathways; number of contacts; type of symptoms leading to contacts with health professionals; interval between initial contact and referral to a specialised outpatient service.MethodThe help-seeking pathways were assessed as part of a prospective study in 104 patients with suspected at-risk states for psychosis.ResultsThe mean number of contacts prior to referral was 2.38. Patients with psychotic symptoms more often contacted mental health professionals, whereas patients with insidious and more unspecific features more frequently contacted general practitioners (GPs).ConclusionsGPs have been found to under-identify the insidious features of emerging psychosis (Simon et al. (2005) Br J Psychiatry 187:274–281). The fact that they were most often contacted by patients with exactly these features calls for focussed and specialised help for primary care physicians. Thus, delays along the help-seeking pathways may be shortened. This may be of particular relevance for patients with the deficit syndrome of schizophrenia.

Developing services for the early detection of psychosis: a critical consideration of the current state of the art.

Recent research has attempted to improve the identification of individuals at-risk of developing schizophrenia to permit targeted early prevention. Two sets of criteria, one characterized by a subgroup of ‘basic symptoms’ [Klosterkötter, Hellmich, Steinmeyer, Schultze-Lutter (2001) Arch Gen Psychiat 58:158–164] and one by the ultra high-risk model [Miller, McGlashan, Woods, Stein, Driesen, Corcoran, Hoffman, Davidson (1999) Psychiatr Q 70:273–287; Yung, McGorry, McFarlane, Jackson, Patton, Rakkar (1996) Schizophr Bull 22:283–303], have been associated with positive predictive values for later schizophrenia. This paper is a critical discussion of these predictive values. In the first part, the paper demonstrates that the predictive values of at-risk criteria are mediated by a strong enrichment effect and depend considerably on the structure of early detection systems. Further, it shows that these predictive values do not apply to the general population level, where subclinical psychosis shows high prevalence and incidence rates, and that these values may be less predictive in adolescents. In the second part, the paper discusses the need for specific sensitization on several levels of an early detection system and proposes a selected overview of prototypical models already applied in this field.

Beginnende Schizophrenien in der hausärztlichen Praxis werden besser erkannt

Hausärzte sind die häufigste erste Anlaufstelle für Patienten mit beginnender Schizophrenie. Die Früherkennung von Schizophrenien ist entscheidend für den weiteren Krankheitsverlauf. Dabei bleiben die unspezifischen Symptome der schizophrenen Frühstadien oft unerkannt. In folgendem Beitrag zeigen wir, dass ein erstmals in diesem Bereich der Medizin erprobtes, repetitives Sensibilisierungsmodell mit klinischen Fallvignetten das diagnostische Wissen der Hausärzte bezüglich früher Warnsymptome beginnender Schizophrenien verbessern kann.