Relationship of positive and negative symptoms to cocaine abuse in schizophrenia

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similarity in socioeconomic status, policy against discrimination or small sample size. Blacks were more likely to be substance abusers, live alone, and to be divorced or separated, suggesting different treatment needs.

FIVE FACTOR REPLICATION J.P. Lindenmayer*, Department Bronx

MODEL OF SCHIZOPHRENIA: ACROSS SAMPLES S. Grochowski,

of Psychiatry,

Psychiatric

Albert

Center, Bronx,

R. Meibach

Einstein

College

of Medicine-

NY 10461. USA

Objective: Our aim was to examine the factor structure of schizophrenic symptomatology in two large independent samples as assessed by the Positive and Negative Syndrome Scale. Methods: The first sample consisted of 240 inpatients selected from a State psychiatric center. All met DSM-III criteria for chronic schizophrenia. The sample was predominantly male (N=179) with an age range of 18 to 68 years (median=31 years). Median duration since first psychiatric hospitalization. The second sample consisted of 523 DSM-III-R schizophrenic inpatients enrolled in a multi-center phase II drug study (median age 37.9 years) who were evaluated on their pre-existing neuroleptics at screening on the Positive and Negative Syndrome Scale (PANSS). Independent factor analyses, with equamax rotation, were done for both samples. Results: Both independent factor analyses confirmed our original model showing five factors (negative, positive, excitement, depression and cognitive), explaining 57.5% and 5 I .7% of respective variances. Conclusion: These findings support our observation that positive and negative dimensions are not sufficient to accommodate the full schizophrenic symptomatology and that there are additional independent, yet coexisting psychopathological dimensions. The replication of the factor structure across samples speaks to their stability and generalizability. This expanded model may relate more consistently to premorbid, genetic, functional and treatment variables. This model may also offer new subtyping approaches in schizophrenia and take into account symptom heterogeneity.

CANNABIS ABUSE AND THE COURSE OF RECENT ONSET SCHIZOPHRENIC DISORDERS Don H. Linszen*, Psychiatric

Peter

Center AMC,

of Amsterdam,

M. Dingemans, Department

Tafelbergweg

Marie

E. Lenior

of Psychiatry,

University

25, 1105 BC Amsterdam,

The Netherlands

The role of cannabis abuse in the etiology and course of schizophrenic illness remains controversial. We studied the relation

between cannabis abuse and the symptomatic course of recent onset schizophrenic disorders over a 12 month period. Of 97 admitted young patients, 93 participated in a prospective cohort study. Symptoms were assessed with the Brief Psychiatric Rating Scale. The course of psychotic and negative sypmtoms was analysed for patients who abused cannabis (n=24) and who did not (n=69). Within the abusing group a distinction was drawn between mild (n=l 1) and heavy (n=13) cannabis abuse. Significantly more and earlier relapses and/or exacerbations of psychotic symptoms occurred in the cannabis abusing group (p=O.O3). This association became stronger, when a distinction was made between mild and heavy cannabis abuse (p=O.O02). Other street drugs were rarely used. No confounding effect of other important variables was found. No relation was found between cannabis abuse and the course of negative symptoms, although an interaction effect was observed between cannabis abuse and time (p=O.O3). Cannabis abuse was associated with more and earlier psychotic relapses. This finding, combined with the patients’ own reports, the onset of cannabis abuse preceding psychotic illness and recent evidence of cannabis acting as dopamine agonist, cannabis abuse can be considered an independent risk factor for a deteriorating course of schizophrenic disorders.

RELATIONSHIP OF POSITIVE AND NEGATIVE SYMPTOMS TO COCAINE ABUSE IN SCHIZOPHRENIA P.H. Lysaker*, Psychology

M.D. Bell, R.M. Milstein, J.L. Goulet

Service.

VA Medical

Center.

West Haven,

CT 06516,

USA

The prevalence of cocaine abuse by patients with schizophrenia had led researchers to investigate features of the disorder correlated with abuse. While abuse has been found to be more common among patients with a diagnosis of the paranoid subtype and a history of more frequent psychiatric hospitalizations, it is unclear if it is related to particular symptom patterns. This study examines the differences in positive and negative symptoms for schizophrenic and schizoaffective patients with and without histories of cocaine abuse. Five factor-analytically derived scores from the Positive and Negative Syndrome Scale (PANSS) are compared for subjects with a history of at least two months of cocaine abuse (n=25), no life time substance abuse (n=20), and 2 months of lifetime abuse of alcohol but no other substance abuse (n=22). Following a significant MANOVA (p<.Ol), univariate analyses indicate significant differences on the negative syndrome factor with the cocaine abusing subjects exhibiting less severe negative symptoms than subjects with no substance abuse history. Implications for the etiology and course of cocaine abuse in schizophrenia are discussed. The utility of employing PANSS factor scores rather than the rationally derived PANSS scores is also reviewed.