Cognitive impairment and substance abuse history as predictors of the temporal stability of negative symptoms in schizophrenia

Association of Negative Symptoms of Schizophrenia Assessed by the BNSS and SNS Scales With Neuropsychological Performance: A Gender Effect

Objective: The relationship between negative symptoms and neurocognitive performance in schizophrenia is well documented, but the mechanism of these connections remains unclear. The study aims to measure the relationship between the results on the new scales for the assessment of negative symptoms such as Brief Negative Symptom Scale (BNSS) and Self-evaluation of Negative Symptoms (SNS), and the results of some neurocognition tests. The second aim is to assess a possible gender effect on these associations. Methods: The study included 80 patients (40 men, 40 women) with schizophrenia, aged 19-63 (mean 38 years), during the improvement period (total PANSS score <80, unchanged pharmacological treatment in the last 3 weeks). They were assessed using the BNSS, SNS, Personal and Social Performance (PSP) scales, and the tests for neuropsychological performance such as the Trail Making Test (TMT-A, TMT-B), Stroop Color-Word Interference Test, Verbal fluency tests (VFT), Category fluency test (CFT), and Digit Symbol Substitution Test (DSST). Results: Male patients obtained higher scores than females on some PANSS and BNSS items. No gender differences were observed for the SNS scale. Female patients scored better in the PSP and CFT. In male patients, a significant positive correlation between the intensity of negative symptoms measured by the BNSS and the results of PSP with the Trail Making Test was observed. In female patients, we found a positive correlation between the results of BNSS and PSP with the Stroop Color-Word Interference Test. Conclusion: The obtained results confirm the relationship between negative symptoms and neurocognition in schizophrenia patients. However, in male and female patients such association was observed for different cognitive domains. Further research is needed to explain the nature of these differences.

Neural markers of negative symptom outcomes in distributed working memory brain activity of antipsychotic-naive schizophrenia patients

Since working memory deficits in schizophrenia have been linked to negative symptoms, we tested whether features of the one could predict the treatment outcome in the other. Specifically, we hypothesized that working memory-related functional connectivity at pre-treatment can predict improvement of negative symptoms in antipsychotic-treated patients. Fourteen antipsychotic-naive patients with first-episode schizophrenia were clinically assessed before and after 7 months of quetiapine monotherapy. At baseline, patients underwent functional magnetic resonance imaging while performing a verbal n-back task. Spatial independent component analysis identified task-modulated brain networks. A linear support vector machine was trained with these components to discriminate six patients who showed improvement in negative symptoms from eight non-improvers. Classification accuracy and significance was estimated by leave-one-out cross-validation and permutation tests, respectively. Two frontoparietal and one default mode network components predicted negative symptom improvement with a classification accuracy of 79% (p = 0.003). Discriminating features were found in the frontoparietal networks but not the default mode network. These preliminary data suggest that functional patterns at baseline can predict negative symptom treatment-response in schizophrenia. This information may be used to stratify patients into subgroups thereby facilitating personalized treatment.

Negative symptoms and cognitive deficits: what is the nature of their relationship?

Negative symptoms and cognitive deficits in schizophrenia share many features and are correlated in their severity on a cross-sectional basis. The question arises as to the nature of this relationship: are these symptoms the same, caused by the same factor (or factors); or is the nature of their relationship determined by other factors, such as definitional issues and common correlates? In this article we provide a conceptual overview for addressing this question and provide a selective review of the literature on the cross-sectional and longitudinal relationships between these two features of the illness. We describe 4 different models of the "true" relationship between these variables. Some data suggest that the relationship between these variables is determined by the definition of negative symptoms employed and that, in general, the correlation is moderate at the most. Further, path modeling suggests the possibility, to be addressed with later research, that correlations between negative and cognitive symptoms and everyday functional outcomes may influence the observed correlations between these variables. Thus, we conclude that negative and cognitive symptoms may be separable, if not conceptually independent, domains of the illness and that it might be possible to develop treatments that target negative symptoms and cognitive deficits independently.

Addiction and schizophrenia

Epidemiologic studies in the general population and those based on the clinical assessment of schizophrenic populations have revealed a high degree of overlap between schizophrenia and addictive disorders. The abuse of psychoactive substances (including alcohol) throughout life is so frequent (50%) that the possibility of a specific link inevitably arises. Various hypotheses have been suggested to explain the high co-morbidity between schizophrenia and addiction: 1) The social-environmental hypothesis has been developed but studies have provided poor evidence to validate it. 2) The possible shared biological vulnerability between schizophrenia and addictions led researchers to explore common genetic determinants and study the involvement of the dopaminergic and opioid systems in the aetiology of both schizophrenia and the abuse of and dependence on psychoactive drugs. 3) Finally, the theory of self-medication suggests that schizophrenics may be attempting to counter the deficit linked to their disorders by using the substances they take or their dependency-type behaviour to cope with their emotional problems. The clinical profile of schizophrenic addicts does seem to display some distinctive features, such as the high level of depressive co-morbidity, very high nicotine and alcohol dependence, with a very poor prognosis. These patients are difficult to manage; the possibility of pharmacologic interactions between the substances they are taking and neuroleptic medication calls for prudence, and their compliance is also poor. Addictive disorders in schizophrenics are currently a topic of active research intended to lead to identifying specific treatments. The early identification of addictive disorders in schizophrenics should make it possible to limit their development and improve the prognosis.

Affect recognition in deficit syndrome schizophrenia

This study has three aims: (1) to compare a deficit syndrome schizophrenia sample (n=19) with a non-deficit sample (n=50) on affect recognition; (2) to determine the association between individual deficit criteria and affect recognition performance in the deficit sample; and (3) to compare the deficit syndrome and negative syndrome samples with respect to affect recognition test performance. Results revealed that the deficit sample had significantly lower adjusted mean affect recognition scores than the non-deficit sample. In addition, 17 of the 19 subjects with deficit syndrome had impairments in affect recognition, whereas, non-deficit subjects were only slightly more likely to score in the impaired range than the unimpaired range. Within the deficit sample Diminished Sense of Purpose was the criterion most strongly associated with affect recognition impairment. Finally, a group of subjects classified as having prominent negative symptoms did not demonstrate the same pattern of impairment as shown by the deficit syndrome sample. The relationship between affect recognition, information processing and the deficit syndrome is discussed along with implications for classification in schizophrenia.

Stability of Psychiatric Symptoms among Mentally Ill Chemical Abusers in Long-Term Residential Treatment Programs

We examined patterns of changes in psychiatric symptoms among mentally ill chemical abusers (MICAs) in long-term residential treatment. Clients were evaluated with various measures of psychopathology, referred to a therapeutic community (TC) or community residence, and reassessed after 2, 6, and 12 months of treatment with regard to anxiety, depressive symptoms, and psychotic ideation. Reductions in mean values of psychopathology were found only for anxiety and depressive symptoms at the TC during the first 2 months of treatment. However, an examination of changing patterns of symptoms revealed a more complex set of findings. At both programs, a significant number of MICAs showed reductions in psychopathology during treatment, a significant minority exhibited no improvements in psychiatric symptoms, and a few reported new symptoms of anxiety, depression, and psychotic ideation. We conclude that the symptoms of the vast majority of MICAs are highly labile during treatment.