Three dimensions of clinical symptoms in elderly patients with schizophrenia: prediction of six-year cognitive and functional status.

BACKGROUND: A three-syndrome categorization of schizophrenia has been recently proposed [Arndt, S., Alliger R.J., Andreasen, N.C., 1991. The distinction of positive and negative symptoms: the failure of a two-dimensional model. Br. J. Psychiatry 158, 317-322; Miller, D.D., Arndt, S., Andreasen, N.C., 1993. Alogia, attentional impairment, and inappropriate affect: their status in the dimensions of schizophrenia. Comp. Psychiatry 34, 221-226; Gur, R.E., Mozley, D., Resnick, S.M., Levick, S., Erwin, R., Saykin, A.J., Gur, R.C., 1991. Relations among clinical scales in schizophrenia. Am. J. Psychiatry 148, 472-478. Brown, K.W., White, T., 1992. Syndromes of chronic schizophrenia and some clinical correlates. Br. J. Psychiatry 161, pp. 317-322].
METHODS: Chronic, elderly, schizophrenia patients with deficit (N = 111), nondeficit with High reality distortion/Low conceptual disorganization (nondeficit-delusional) (N = 40) and nondeficit with Low reality distortion/High conceptual disorganization (nondeficit-disorganized) (N = 56) were followed-up for 6 years. Assessment included the Positive and Negative Syndrome Scale (PANSS), the Mini-mental Status Examination (MMSE) and the Alzheimer's Disease Assessment-Late Stage Cognitive and Non-Cognitive Subscale (ADAS-L Cog and ADAS-L Self care).
RESULTS: At initial assessment, MMSE scores were significantly lower, while the ADAS-L Cog and Negative symptoms were significantly higher in the deficit and nondeficit-disorganized groups compared with the nondeficit-delusional group (all p values <0.05). Positive symptoms were significantly lower in the deficit group than in both nondeficit syndrome groups (p < 0.05). On the ADAS-L Self Care scale the nondeficit-delusional group was the most impaired while the nondeficit-disorganized was the least impaired. There was a significant decline over time in MMSE scores in the deficit and the nondeficit-delusional groups (p < 0.01), but no change in the nondeficit-disorganized group. ADAS-L Cog and ADAS-L Self Care functions worsened over time in all three groups (p < 0.0001). Severity of negative symptoms was stable over time in deficit patients and in nondeficit-disorganized patients but worsened in nondeficit-delusional patients (p < 0.001). There was also a significant worsening of positive symptoms over time in deficit patients (p = 0.04).
CONCLUSION: Deficit, nondeficit-delusional and nondeficit-disorganized patients with schizophrenia may represent distinct subgroups discriminated by different courses in negative and positive symptoms and cognitive status.