Literature Review: Schizophrenia

In this regular feature, members of the editorial board of Medscape Mental Health scan the recently published psychiatric literature and provide their insights and commentary on significant articles. [Medscape Mental Health 2(4), 1997. © 1997 Medscape, Inc.]

Attentional Impairments in Deficit and Nondeficit Forms of Schizophrenia

Buchanan RW, Strauss ME, Breier A, et al: Am J Psychiatry 154:363-370, 1997

Abstract: Previous studies of attention/information processing impairments in schizophrenia suggest that patients with the deficit syndrome should be characterized by impaired performance on measures of visual information processing. Performance on a degraded stimulus version of the continuous performance test and span of apprehension task was examined in 20 deficit and 56 nondeficit patients with schizophrenia and in 27 subjects in a normal comparison group. Deficit patients performed significantly less well than both nondeficit patients and the normal comparison group on the continuous performance test and span of apprehension task. The results suggest that deficit patients are uniquely characterized by impaired performance on the continuous performance test. Their differential performance on this test may be related to either an inability to activate and allocate attention or an impairment in the perceptual organization of visual information.

Comparison of Efficacy of Social Skills Training for Deficit and Nondeficit Negative Symptoms in Schizophrenia

Kopelowicz A, Leberman RP, Mintz J, et al: Am J Psychiatry 154:424-425, 1997

Abstract: The purpose of this pilot study was to compare the efficacy of social skills training for individuals with schizophrenia who did or did not have the deficit syndrome. Three subjects with the deficit syndrome and 3 with nondeficit negative symptoms received 12 weeks of social skills training. Social skills and negative symptoms were evaluated before and after training and at 6-month follow-up. Patients with schizophrenia who did not have the deficit syndrome demonstrated significantly better social skills and lower negative symptoms both after training and at follow-up than did those who had the deficit syndrome. Schizophrenic patients with nondeficit negative symptoms appear amenable to intensive social skills training, but schizophrenic patients with the deficit syndrome may have significant deficits in skill acquisition.

Editorial Comment

The important research group of Buchanan and colleagues has previously characterized the deficit syndrome in schizophrenia. Individuals with this syndrome tend to have negative symptoms that are enduring and not secondary to positive symptoms, depression, or drug side effects. Prior reports indicate that patients with the deficit syndrome have a greater tendency to have structural brain abnormalities, impairments on certain neuropsychological tasks, and poor premorbid adjustment. In this report, the authors indicate that patients with the deficit form of schizophrenia also demonstrate poorer performance on measures of visual information processing. This finding suggests that these patients may be less able to discriminate relevant from irrelevant information when given a difficult task. Furthermore, it suggests important obstacles that clinicians who are designing rehabilitation programs for these patients may face. The report by Kopelowicz and colleagues used the same definition of the deficit syndrome used by Buchanan and coworkers. They compared the ability of deficit and nondeficit patients to acquire skills during social skills training. The deficit patients did not demonstrate meaningful changes in skills following the training; this suggests that these training methods may need to be modified for deficit patients. This study also supports the findings of Buchanan and coworkers by indicating that patients with the deficit state appear to suffer from neurocognitive impairments that may interfere with learning.

Stephen R. Marder, MD
West Los Angeles VA Medical Center

Symptoms, Subtype, and Suicidality in Patients With Schizophrenia Spectrum Disorders

Fenton WS, McGlashan TH, Victor BJ, et al: Am J Psychiatry 154:199-204, 1997

Abstract: Suicide is the single largest cause of premature death among individuals with schizophrenia. This report examines the relationship between positive or negative symptoms, illness subtype, and suicidal behavior among patients with schizophrenia and schizophrenia spectrum disorders in a long-term follow-up cohort. Based on index admission records, patients from the Chestnut Lodge Follow-Up Study with schizophrenia (n = 187), schizoaffective disorder (n = 87), schizophreniform disorder (n = 15), and schizotypal personality disorder (n = 33) were retrospectively assessed with the Positive and Negative Syndrome Scale, classic subtype criteria, and criteria for the deficit syndrome. Completed suicides, suicide attempts, and suicidal ideation during the follow-up period (average, 19 years) were ascertained by means of interviews with patients and/or surviving relatives. Over the follow-up period, 40% of the patients reported suicidal ideation, 23% reported suicide attempts, and 6.4% died from suicide. Patients who died from suicide had significantly lower negative symptom severity at index admission than patients without suicidal behaviors. Two positive symptoms (suspiciousness and delusions), however, were more severe among successful suicides. The paranoid schizophrenia subtype was associated with an elevated risk of suicide (12%), and the deficit subtype was associated with a reduced risk (1.5%). These findings suggest that prominent negative symptoms, such as diminished drive, blunted affect, and social and emotional withdrawal, counter the emergence of suicidality in patients with schizophrenia spectrum disorders, and that the deficit syndrome defines a group at relatively low risk for suicide. Prominent suspiciousness in the absence of negative symptoms defines a relatively high-risk group.

Editorial Comment

The authors are interested in the relationship between symptoms and suicide risk in schizophrenia. The database was the Chestnut Lodge Fol- low-Up Study, which included all patients discharged from that facility between 1950 and 1975. Patients were retrospectively evaluated using modern diagnostic and symptoms scales documented on medical records. Prominent negative symptoms characterized a population with a relatively low risk for suicide. On the other hand, patients with suspiciousness and delusions were more likely to commit suicide. These results may be helpful to clinicians who are concerned with identifying populations at greater risk for suicide.

Stephen R. Marder, MD
West Los Angeles VA Medical Center