Have the times come for early intervention in psychosis?
2001; Wiley; Volume: 103; Issue: 5 Linguagem: Inglês
10.1034/j.1600-0447.2001.00009.x
ISSN1600-0447
Autores Tópico(s)Child and Adolescent Psychosocial and Emotional Development
ResumoThe development of early intervention programmes in psychosis has generated a marked interest and a rising hope in the community of mental health clinicians, but has also raised a debate on the feasibility and the efficacy of such programmes. The papers from Larsen and colleagues (1) and from Bosveld-van Haandel and colleagues (2) published in the current issue of Acta Psychiatrica Scandinavica are two major contributions highlighting the complexity of this area of research. After having carefully reviewed the literature on past and ongoing studies on early intervention programmes in first-episode schizophrenia, Larsen et al. (1) conclude that a large number of questions remained unanswered with regard to the efficacy such programmes. The existence of a causal relationship between longer duration of untreated psychosis and poorer outcome is not yet perfectly established (3). The delay between onset of psychosis and first treatment is not randomly distributed with regard to the other characteristics of the disease, thus we cannot exclude that the association between DUP and outcome is a spurious one, due to the fact that the factors delaying treatment seeking are also independently predicting poor outcome (4). Furthermore, the existing studies have not yet definitively demonstrated that early intervention is more efficient than intervention at a later stage, at least with regard to subsequent outcome. Despite the limitations of the available studies inherent in the methodological complexity of this research, the authors of these studies must be profoundly acknowledged for having initiated this necessary and exciting debate. Even if we postulate that the ongoing studies will show clearly in the future that shortening the duration of untreated psychosis by early intervention has a dramatic positive impact on outcome, the next step will be to move from a research approach to a public health perspective, and to explore whether the development of early intervention programmes would be more beneficial for the community than the usual therapeutic strategies. A preliminary question is that we will have to clarify to which population(s) early identification programmes should be proposed. Schematically, two approaches may be chosen: a prevention strategy focused on high-risk subjects or a population-based strategy. A prevention focused on high-risk subjects, such as relatives of patients with psychosis, or subjects already identified as suffering from a mental health disorder, may be considered at first glance as the most efficient and less costly strategy. However, a cornerstone principle, applying to prevention of diseases for which the risk is not clearly restricted in a well-identified subgroup of subjects from the general population, is that a large number of people exposed to a small risk may generate more cases than a small number of subjects exposed to a high risk (5). In other words, a strategy focused on high-risk subjects will not be able to identify early most cases of psychosis in the general population. An intermediate strategy, chosen by some ongoing intervention studies, is based upon education programmes on psychotic symptoms of the general population, aimed at favouring help-seeking behaviour in subjects presenting such symptoms. The limit is that it is not possible to assess which proportion of subjects in the general population with incipient psychosis benefit from these early detection programmes, and whether these subjects are similar to those who are not included in these programmes, for example in terms of illness severity, or in social adjustment and social network. Always postulating that early intervention is an efficient strategy, should we not try to give everybody the same chance to be treated as soon as possible? Should we not try to go further and to identify as early as possible most, if not all, cases of incipient psychosis in the general population? Thus, the next questions are: which screening tests are available to early identify subjects with incipient psychosis in the general population? What are the sensitivity, specificity and predictive positive value of these tests? What are the percentages of false positive and false negative results? If a test is negative at one point, do we have to consider that the subject is definitely out of risk, or do we have to repeat the test and, if yes, at what frequency? What we know at this time is that delusional or hallucinatory experiences are frequent in subjects from the general population, and at least much more frequent than the prevalence of cases of psychotic disorders (6, 7). What we also know is that subjects presenting with psychotic symptoms are at increased risk of subsequent psychotic or affective disorder (8, 9). However, the positive predictive value of psychotic symptom is very low. For example, in the NEMESIS study (7), subjects presenting with three psychotic symptoms at baseline were 23 times more likely to present a psychotic disorder 3 years later, but less than 3% of these subjects were diagnosed suffering a psychotic disorder at the follow-up assessment (personal communication, J. van Os, 2000). What are the consequences of such findings? We are not yet able to predict which subjects from the general population presenting psychotic symptoms will develop a full-blown psychotic disorder in the subsequent years. Thus, how can we decide which subject should benefit from early treatment? The rate of conversion to psychosis is of course higher in subjects recruited in high-risk groups (1), but the questions related to therapeutic decision are basically the same for high-risk subjects and for subject from the general population presenting with psychotic symptoms. These questions are: how many subjects will receive treatment that they do not require, with which consequences? Although the review by Bosveld-van Haander and colleagues (2) reminds us that several questions remain unanswered with regard to the optimal duration and doses of prophylactic antipsychotic treatment in subjects already identified as cases of psychosis, the benefits of a maintenance treatment are clearly higher in these subjects than the disadvantages linked to antipsychotic medication. This review also reminds us that few randomized controlled trials have been performed in subjects with first-episode schizophrenia. In ‘prepsychotic’ subjects, the assessment of the risk/benefit ratio of antipsychotic treatment is a much more complex issue with strong ethical implications, since we know the disadvantages of these treatments but were are not yet sure of their benefit, and only empirical data are available with regard to optimal doses and duration of antipsychotic treatment in ‘prepsychotic’ subjects. Early intervention is not equivalent to early antipsychotic treatment, and most research projects on early intervention are based upon the use of psychotherapic interventions. The negative consequences of such treatments are not comparable to those induced by antipsychotic medication. However, stigmatization associated to mental illness is still a major problem in our societies, thus we should consider the impact in terms of distress for the subject and her/his relatives of being labelled as presenting a potential risk of subsequent psychotic illness in the future (or whatever the term used, since it necessarily implies a risk of mental illness). How many subjects will be distressed without justification? The time has surely come to ask questions. From a public health perspective, the time has perhaps not yet come to be overconfident in the feasibility of early intervention programmes, and in the benefit of such programmes for the community. Acta Psychiatrica Scandinavica Professor Hélène Verdoux Invited Guest Editor
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