A decade of debate on early intervention in psychosis: a systematic review of screening criteria

Systematic screening for unsafe driving due to medical conditions: still debatable

Background

Assessing people's ability to drive has become a public health concern in most industrialized countries. Although age itself is not a predictive factor of an increased risk for dangerous driving, the prevalence of medical conditions that may impair driving increases with age. Because the implementation of a screening for unsafe driving due to medical conditions is a public health issue, its usefulness should be judged using standardised criteria already proposed for screening for chronic disease. The aim of this paper is to propose standardised criteria suitable to assess the scientific validity of screening for unsafe driving due to medical conditions, and identify potential issues to be clarified before screening can be implemented and effective.

Discussion

Using criteria developed for screening for chronic diseases and published studies on driving with medical conditions, we specify six criteria to judge the opportunity of screening for unsafe driving due to medical conditions. This adaptation was needed because of the complexity of the natural history of medical conditions and their potential consequences on driving and road safety. We then illustrate that published studies pleading for or against screening for unsafe driving due to medical conditions fail to provide the needed documentation. Individual criteria were mentioned in 3 to 72% of 36 papers pleading for or against screening. Quantitative estimates of relevant indicators were provided in at most 42% of papers, and some data, such as the definition of an appropriate unsafe driving period were never provided.

Summary

The standardised framework described in this paper provides a template for assessing the effectiveness (or lack of effectiveness) of proposed measures for screening for unsafe driving due to medical conditions. Even if most criteria were mentioned in the published literature pleading for or against such a screening, the failure to find quantitative and evidence-based estimates of relevant indicators provides useful insight for further research.

Recent approaches to psychological interventions for people at risk of psychosis

With the emerging global focus on early psychosis, indicated prevention in schizophrenia has increasingly become a focus of psychiatric research interests. It has been argued that CBT may have some advantages compared with antipsychotics regarding this issue. According to MEDLINE, EMBASE and Psycinfo two completed randomised controlled trials (RCTs; PACE, Melbourne, Australia; EDIE, Manchester, United Kingdom) and one ongoing RCT with only preliminary results published so far (FETZ, Cologne/Bonn, Germany) on indicated prevention in schizophrenia including manualised and standardised psychological treatment can be identified. The aims of the present paper are to present and discuss the three approaches with regard to (I) inclusion, exclusion and exit criteria, (II) characteristics of interventions and (III) evaluations. All interventions use intake, exclusion and exit criteria, which have been evaluated in prospective follow-along studies. The approaches are based on the general structure and principles of cognitive behavioural therapy which have been developed, applied and evaluated in a wide range of mental health problems. Despite several methodological limitations, the first evaluations indicate some effects with regard to three possible aims of early intervention: (1) improvement of present possible pre-psychotic symptoms, (2) prevention of social decline/stagnation and (3) prevention or delay of progression to psychosis. Even though the first results are promising, we conclude that several ethical issues have to be taken into consideration and further predictive and therapeutic research is needed to judge whether psychological intervention is a realistic option for the treatment of people at risk of psychosis.

Faut-il mettre en place des programmes de dépistage des troubles psychotiques débutants ?

Programs for the early detection of psychosis are currently underway in most developed countries. Their aim is to improve the outcome of subjects with psychotic disorders, but neither their feasibility nor their usefulness was assessed before their implementation. The postulate underlying these programs - that early treatment improves the prognosis of psychosis - has not yet been demonstrated. The absence of effective and adequately specific screening tests implies that a substantial number of the subjects evaluated may be incorrectly diagnosed with and treated for psychoses (false positives). Development of facilities specializing in the assessment and care of subjects with early psychosis often implies a decrease in funding for facilities caring for patients with chronic psychoses. Educational and information campaigns aimed at the general public and health professionals, on the other hand, may help reduce the stigma associated with psychosis and improve access to care for subjects in early stages of psychosis. Risk/benefit and cost/benefit analyses of programs for the early detection of psychosis must be evaluated before promoting their development.

Toward a world consensus on prevention of schizophrenia

Screening for preschizophrenia in the general population with the aim of preventing transition to full-blown illness is an epidemiological impossibility because a rare disease cannot be predicted. The lack of specificity resulting in abundance of false-positives can be remedied in part by using much more restrictive screening criteria that combine several indicators of risk for transition to schizophrenia. Raising the specificity (reducing the false-positives), however, can only be done at the expense of sensitivity (increasing the false-negatives). The most commonly used strategy to raise specificity is the sample enrichment strategy. This involves the creation of samples enriched with schizophrenia risk by selectively filtering at-risk people out over a range of consecutive referral processes starting in the general population, through to general practioners, mental health services, and the early detection clinic. However, improvements in specificity obtained by the sample enrichment strategy should not be attributed to the use of some predictive instrument that supposedly identifies high-risk individuals. The epidemiologically and ethically most viable way for screening and early detection is to selectively increase the permeability of the filters on the pathway to mental health care. This will occasion samples of help-seekers enriched with schizophrenia risk at the level of mental health services (thus reducing false-positives), while at the same time making an attempt to "attract" as many detectable schizophrenia prodromes as possible through the filters along the pathway to mental health care (thus reducing false-negatives). Early psychosis research has yielded some useful suggestions in that it is becoming increasingly clear that it is not just psychosis itself, but rather the clinical context of the psychotic experience that determines risk for transition to schizophrenia. Thus, risk for transition to full-blown psychotic disorder is to a large degree determined by size of psychosis "load," comorbid distress and depression, cannabis use, cognitive ability, and subjective reports of impairment and coping. Making a diagnosis of psychotic disorder is not an exact science: it involves an arbitrary cutoff imposed on dimensional variation of psychopathology and need for care over time. Gaining insight into the cognitive and biological factors that drive the dimensional variation, including therapeutic interventions, is arguably more useful than sterile dichotomous prediction models.