هذیان های اسکیزوفرنی: تشخیص سیگنال های هشدار دهنده

Schizophrenic delusions are important target symptoms for treatment. This study aims to identify predictors of delusion formation. Two samples of schizophrenic patients (total n=131) are examined prospectively every second week during a period of 6 months. In one sample (n=60) delusion formation (n=27; 45%) is correlated significantly with a change in score of eight individual items from the Early Signs Scale (ESS): sleep, anxiety, concentration, irritability, coping, tiredness, depression and confusion. These eight items form the Warning Signals Scale (WSS). The predictive validity of the scale is tested in another sample (n=71), of which 43 patients (61%) have reemergence of delusions. A criterion cut-off score of ≥5 points combines an acceptable sensitivity (77%) and specificity (68%). The scale is acceptable to patients, manageable for clinicians, and it has a high degree of predictive validity and reliability. This makes it relevant for implementation in ordinary clinical practice.

Delusions are prominent features that may veil any other psychotic symptom or problem in patients with schizophrenia. Therefore, delusions are important target symptoms for treatment in clinical psychiatry, and this raises the question how to prevent their formation. Classic authors recognize a predelusional state which has been designated by numerous terms: e.g., Wahnstimmung, Trema, fait primordial, conscience morbid and perplexity. Because of its fleeting and kaleidoscopic nature and opaqueness to analysis, this mental state has not been well studied. During predelusional state the patient is expected to report experiences for which he may not even have a name and for which the interviewer has no conceptual clarity. Experiences that are similar may thus be reported as depersonalization, bodily sensations, dysphoria, changes in perception of reality or time, dissolution of ego boundaries, etc. It is therefore not surprising that, since the 19th century, predelusional state has been considered in turn a disorder of cognition, emotions, volition and consciousness (Fuentenebro and Berrios, 1995). In modern psychiatry most studies are based on populations defined by diagnostic categories rather than individual symptoms. Therefore, past interest in the predelusional state has been replaced by current attention to the prodromal phase of schizophrenia and affective disorder. The concept of prodrome is, however, unclear but agreed on as a precursor of schizophrenic symptoms. The most common early signs of impending relapse are those of increased subjective dysphoria such as agitation, anxiety, tension and depression, as well as social withdrawal and difficulty sleeping. Nevertheless, Bustillo et al. (1995)suggest that the effective clinical use of early signs depends on, for instance, the inclusion of both psychotic and non-psychotic symptoms. As reviewed by Norman and Malla (1995)only few studies have assessed the direct relationship between putative prodromal symptoms and the exacerbation of psychosis. The main aim of this study was to test the predictive validity (sensitivity and specificity) of self-reported early signs of schizophrenic delusions: 1. Which are the ESS items in which changes predict delusion formation in schizophrenic patients? 2. To what degree do these items predict delusion formation in another sample when delusion formation is defined as a rating of moderate or greater on the Positive Scale of PANSS when preceded by an initial remission period?

Two study samples were selected. Table 1 shows the samples distributed according to gender, age, illness duration, and PANSS and ESS score. At the beginning of the study the samples were comparable, except for the fact that patients in Sample 2 disclosed no positive symptoms. Table 1. Gender, age and mental condition (PANSS and ESS) of two samples of schizophrenic patients Variable Sample 1 (n=60) Sample 2 (n=71) Male gender n 39 44 % 65 62 Age (years) Mean 37 39 SD 10 12 First psychotic episode (age) Mean 24 23 SD 7 8 PANSS—total Mean 65 53 SD 11 14 ESS—total Mean 27 26 SD 10 13 PANNS, Positive and Negative Syndrome Scale; ESS, Early Signs Scale. Table options All patients were maintained on neuroleptic medication during the entire observation period. 3.1. Warning signals in Sample 1 Twenty-seven (45%) of the 60 patients in Sample 1 experienced delusion formation during the observation period; 16 (27%) were readmitted. On average, the score of PS delusions increased from 2.8 to 5.6 (range 4–7) in patients with delusion formation. In comparison, the score changed from 2.9 to 2.8 on average (range 0–4) in patients with no change in delusion activity. The patients' replies to the ESS were very heterogeneous and changeable. Changes in individual items (higher score) in relation to the baseline ESS score preceded the delusion formation in some patients. Table 2 shows the items with a significant correlation between change in self-reported score and delusion formation. Table 2. Changed experience as warning signal to delusional formation Delusion formation (n=27) No delusion formation (n=33) Items n Sensitivity (95% CI) n Specificity (95% CI) 1 Sleep has been restless or unsettled 19 70 (50–86) 7 79 (61–91) 2 Feeling tense, afraid or anxious 15 56 (35–75) 4 88 (72–97) 3 Having difficulty concentrating 10 37 (20–58) 1 97 (84–100) 4 Feeling irritable or quick tempered 13 48 (29–68) 2 94 (80–99) 5 Feeling unable to cope, difficulty in managing everyday tasks and interests 17 63 (42–81) 5 85 (68–95) 6 Feeling tired or lacking energy 14 52 (32–71) 3 91 (76–98) 7 Feeling depressed or low 13 48 (29–68) 2 94 (80–99) 8 Feeling confused or puzzled 9 33 (17–54) 0 100 (89–100) Table options In this sample 24 patients (40%) changed their score in at least five of the eight items. Subsequently, 21 patients (88%) developed delusions while three patients (13%) did not. A cut-off score of ≥5 points provided a sensitivity of 78% (95% CI 58–91) and a specificity of 91% (95% CI 76–98) to delusion formation. 3.2. Delusion formation in Sample 2 The 71 patients in Sample 2 were additionally monitored using the selected ESS items that had proved significant correlation to delusion formation. This subgroup of ESS items was named the Warning Signals Scale (WSS), with a score 1 for having experienced the problem within the last 2 weeks and 0 for not (Appendix A). To test the reliability of the patients' WSS self-reporting they were asked to monitor twice with a 2-week interval. Test–retest reliabilities for the items were: 1, 0.82; 2, 0.86; 3, 0.80; 4, 0.80; 5, 0.82; 6, 0.90; 7, 0.82; 8, 0.93. During the observation period 43 patients (61%) developed delusions. For these patients the rating on the PS increased from 1.0 to 6.2 points on average (range 4–7). For patients who did not develop delusions the rating changed from 1.0 to 1.4 on average (range 1–3). For many patients (n=27; 63%) delusions were accompanied by other positive symptoms. In a few patients (n=4; 6%) positive symptoms such as conceptual disorganization, excitement and hostility developed, but no delusions. Some patients had various problems of the kind mentioned in the WSS: sleep, anxiety, concentration, etc., but the problems were stable so the answer to the WSS was negative. The patients were instructed to monitor changes/worsening for the items in question only. Table 3 shows the total WSS score for patients in relation to delusion formation. Moreover, it illustrates the significance of an increased ESS score for delusions. The table includes sensitivity and specificity in the cases where a WSS score and increased ESS score predicted delusion formation. A criterion cut-off score of ≥5 points on the WSS combined a high degree of sensitivity (77%) and specificity (68%). The importance of this cut-off score corresponded rather well to the importance of an increased ESS total score of ≥10 points. Table 3. Warning signals (WSS, ESS) and schizophrenic delusions Schizophrenic delusions (n=43) No delusions (n=28) WSS score n Sensitivity (95% CI) n Specificity (95% CI) 1 39 91 (78–97) 21 25 (11–45) 2 36 84 (69–93) 21 25 (11–45) 3 36 84 (69–93) 19 32 (16–52) 4 35 81 (67–92) 14 50 (31–69) 5 33 77 (61–88) 9 68 (48–84) 6 27 63 (47–77) 5 82 (63–94) 7 18 42 (27–58) 4 86 (67–96) 8 17 40 (25–56) 4 86 (67–96) Increased ESS-score (≥10) 30 70 (54–83) 9 68 (48–84) WSS, Warning Signals Scale; ESS, Early Signs Scale. Table options A total of 42 patients (59%) scored ≥5 points on the WSS during the observation period. In the majority of patients (n=33; 77%) delusions were formed subsequently; for all but one this happened within 4 weeks. For one patient the temporal link of warning signals to delusions was 6 weeks. In nine patients (23%) the increased score was followed by no delusions.