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PREMORBID NEUROPSYCHOLOGICAL PERFORMANCE AS A RISK FACTOR FOR SCHIZOPHRENIA: 13-YEAR FOLLOW-UP OF 50 000 CONSCRIPTS

A.S. David*, A. Malmberg, G. Lewis, L. Brandt, P. Allebeck

Department of Psychological Medicine, Institute of Psychiatry, London SE5 8AF, UK

Neuropsychological functioning is impaired in patients with schizophrenia. Prospective data from US army inductees and children treated in Child Guidance Clinics, indicate that this impairment probably predates the onset of illness. We have retrieved detailed psychometric test scores covering verbal and visuo-spatial IQ, plus mechanical and general knowledge, from 50000 Swedish conscripts. By virtue of linkage between these data and the Swedish National Register of Psychiatric Care, it has been possible to calculate the relative risk for schizophrenia and other psychoses, of poor performance on these tests, in relation to the population as a whole, over the follow-up period. The results show that, the poorer the performance, the greater the risk of schizophrenia, even after adjustment for potential confounders including family background, personal- ity, and psychiatric disturbance at conscription. The latter is important since it suggests that neuropsychological deficits cannot be a reflection of a prodrome of later psychosis. Verbal IQ and mechanical knowledge emerged as specific predictors, taking into account overall IQ. These results have implications for developmental theories of schizophrenia.

MINI-MENTAL STATE EXAMINATION AND TRAIL MAKING TEST IN SCHIZOPHRENIC INPATIENTS

J. de Leon*, R. Doonan, G.M. Simpson

Norristown State Hospital Clinical Research Center, Norristown, PA 19401, USA

There are two main strategies utilised to explore the cognitive deficits present in psychiatric patients: the bedside instruments and neuropsychological tests. There are very few studies com- paring both. In this study, the Mini-Mental State Examination (MMSE) and the Trail Making Test, part B (TMT-B) were compared, as screening instruments in a sample of 80 inpatients hospitalized in a long-term hospital with a DSM-IIIR diagnosis of schizophrenia (n=63) or schizoaffective disorder (n=17). The TMT-B (using Bornstein's norms) classified 86% as cogni- tively impaired. The classical M MSE cutoff score (~< 23), using serial sevens and spelling respectively, classified as impaired 45% and 24% of the patients. The new MMSE norms, which correct by age and education, classified 74% as impaired. The agreements for impairment (kappa) between TMT-B and any of the three ways of scoring the MMSE was very low and non- significant. The kappas reached significant levels for inability

to complete TMT-B and old MMSE cutoff scores. The TMT-B appears to be a more appropriate instrument to screen for cognitive deficits in schizophrenic patients.

NEUROPSYCHOLOGY OF ELDERLY SCHIZOPHRENIA

John A. Dent*, Christiane Hornstein, Paul Richter, Ann M. Mort imer

Department of Psychiatry, Charing Cross & Westminster Medical School, Fulham Palace Road, London W6, UK

Although a high prevalence of cognitive impairment is now recognised in elderly schizophrenia patients, its natural history, neuropsychological characterisation and neuropathology remain relatively unexplored. 100 elderly schizophrenic inpa- tients from three hospitals were assessed as part of a prospective postmortem study. The confirmed high prevalence of general cognitive impairment (MMS exam) appeared to be the result of a steep fall in IQ from essentially normal original levels. Apparently cognitively intact patients nevertheless demon- strated both decline in performance (comparing premorbid IQ with current estimates) and specific deficits in 'executive' and memory function. Such disproportionate deficits have been described in younger patients. Psychomotor poverty syndrome was strongly related to extent and severity of cognitive decline while disorganisation syndrome was most strongly and inversely related to age; reality distortion syndrome was strongly and inversely related to general cognitive capacity. Comparing 'demented' patients with the 'intact' group, the 'intact' group had half the poverty and disorganisation but 1/3 more reality distortion. One interpretation is that patients develop specific deficits as a prodrome to general impairment, suggesting a degenerative process. Syndrome profiles may not be closely linked to specific deficits in the elderly compared with younger patients owing to additional factors such as ageing, institu- tionalisation and medication.

MOTOR SEQUENCING DEFICITS IN SCHIZOPHRENIA AND PARKINSON'S DISEASE

A. Deshmukh*, E.V. Sullivan, P.K. Shear, M. Stein, J. Lin, R.B. Zipursky, A. Pfefferbaum

Department of Psychiatry, D VA and Stanford University School of Medicine, Palo Alto, CA 94304, USA

Motor abnormalities are well-documented in patients with schizophrenia (SZ), whether or not treated with neuroleptics. This study examined whether the severity and type of motor disability observed in SZ was similar to that in patients with a known neurological motor disorder, idiopathic Parkinson's disease (PD). We assessed 29 neuroleptically treated SZ, 16 conventionally medicated PD, and 89 normal controls (NC)