Tania Pampoulova

Increased extrapyramidal symptoms in patients with schizophrenia and a comorbid substance use disorder

Few data have been gathered about the impact of psychoactive substances on extrapyramidal symptoms (EPS) in schizophrenia, and so far, inconsistent results have been reported. We studied 41 outpatients with schizophrenia (based on DSM-IV criteria), who were divided into two groups: with (n = 17) and without (n = 24) a substance use disorder (alcohol, cannabis, and/or cocaine). Both groups were matched for sociodemographic data and psychiatric symptoms (Positive and Negative Syndrome Scale). EPS were evaluated with the Extrapyramidal Symptoms Rating Scale and the Barnes Akathisia Scale, and all patients were stable on either quetiapine or clozapine. Patients receiving anticholinergic drugs were excluded. Analyses of variance were conducted on both groups and showed that schizophrenia patients with a comorbid substance use disorder (especially cocaine) displayed more EPS compared with non-abusing patients.

Relationship between psychotic and obsessive compulsive symptoms in schizophrenia.

The presence of obsessive compulsive symptoms (OCSs) in schizophrenia was recognized as early as the first descriptions of the illness. Studies investigating the association between OCSs and schizophrenia have defined their co-occurrence in terms of co-morbidity and compared schizophrenia patients separated into groups according to whether they presented OCSs or not. However, most of these studies did not take both the complexity of the schizophrenia phenomenology and that of OCSs into account. The present research investigates the relationship between schizophrenia symptoms and OCSs using a correlational approach with a dimensional perspective in order to determine how the OCSs contribute to symptom expression in schizophrenia. Fifty nine schizophrenia patients were rated for schizophrenia symptoms (SAPS-SANS) and OCSs (Y-BOCS). Schizophrenia symptoms scores were collapsed into four dimensional scores and OCSs into for other dimensional scores. The latter were entered as explanatory variables to determine their associations with schizophrenia dimension scores using series of stepwise regression models. The results showed a strong positive relationship between Delusions and Obsessions consistent with the view that they reflect manifestations of the similar mechanisms. Similar results indicate an association between Auditory hallucinations and Compulsions also suggesting that they share common mechanisms. On the other hand, there were inverse relationships between Somatic Obsessions and Disorganization and between Hoarding/Collecting Compulsions and Delusions or Auditory hallucinations. These results may reflect that these OCSs have a protective effect against disorganization and psychotic symptoms respectively.

The cognitive and anatomo-functional basis of reality distortion in schizophrenia: A view from memory event-related potentials

This study investigated the neural and cognitive correlates of reality distortion in schizophrenia by using event-related potentials (ERPs) recorded in a recognition memory task for face. This task has been chosen because previous studies have shown that it provides distinct indices related to specific cognitive processes and to the functioning of specific brain regions. ERPs have been recorded in controls and schizophrenia patients separated into high scorers (RD+) and low-scorers (RD-) according to their Reality Distortion score (hallucination and delusion SAPS subscales). The results indicate that RD+ presents abnormalities on various cognitive processes. First, RD+ are deficient at interference inhibition and knowledge integration (reduced P2a and N400 effect). The similar impairments found in RD- suggest that they represent basic traits of the illness. Second, RD+ showed inappropriate stimulus categorization and contextual integration (larger N300 and fronto-central effect). Third, RD+ showed a late index (P600 effect) not different from controls, but larger than in RD-. This result is consistent with a qualitative, rather than quantitative, impairment of mnemonic binding processes (inappropriate binding) in RD+. Since each of the ERP abnormalities observed represents associated with distinct brain dysfunction, the results are further discussed in regard of the respective contribution of the parietal, frontal and hippocampal structures to reality distortion symptoms.

Sensation-seeking, social anhedonia, and impulsivity in substance use disorder patients with and without schizophrenia and in non-abusing schizophrenia patients

Substance use disorders (SUDs) are common in patients with schizophrenia and this comorbidity is associated with a poorer prognosis, relative to non-abusing patients. One hypothesis that has been advanced in the literature is that dual diagnosis (DD) patients may have a different personality profile than non-abusing schizophrenia patients. The present case-control study aimed to characterize levels of personality traits (sensation-seeking, social anhedonia, and impulsivity) in substance abuse/dependence patients with (DD group; n=31) and without schizophrenia (SUD group; n=39), relative to non-abusing schizophrenia patients (SCZ group; n=23), and healthy controls (n=25). Impulsivity was assessed using the Barratt Impulsivity Scale. Sensation-seeking was assessed using the Zuckerman Sensation Seeking Scale. Social anhedonia was assessed with the Chapman Social Anhedonia Scale. We found that sensation-seeking was significantly higher in DD and SUD, relative to SCZ patients. We found that social anhedonia was significantly elevated in DD and SCZ, relative to healthy controls. We found that impulsivity was significantly higher in DD, SCZ and SUD patients, compared to healthy controls. The results suggest that sensation-seeking is prominent in substance abuse/dependence (irrespective of schizophrenia), social anhedonia is prominent in schizophrenia (irrespective of substance abuse/dependence), and impulsivity is prominent in all three populations.

Antipsychotic agents for the treatment of substance use disorders in patients with and without comorbid psychosis.

Substance dependence has serious negative consequences upon society such as increased health care costs, loss of productivity, and rising crime rates. Although there is some preliminary evidence that atypical antipsychotic agents may be effective in treating substance dependence, results have been mixed, with some studies demonstrating positive and others negative or no effect. The present study was aimed at determining whether this disparity originates from that reviewers separately discussed trials in patients with (DD) and without (SD) comorbid psychosis. Using electronic databases, we screened the relevant literature, leaving only studies that used a randomized, double-blind, placebo-controlled or case-control design that had a duration of 4 weeks or longer. A total of 43 studies were identified; of these, 23 fell into the category of DD and 20 into the category of SD. Studies in the DD category suggest that atypical antipsychotic agents, especially clozapine, may decrease substance use in individuals with alcohol and drug (mostly cannabis) use disorders. Studies in the SD category suggest that atypical antipsychotic agents may be beneficial for the treatment of alcohol dependence, at least in some subpopulations of alcoholics. They also suggest that these agents are not effective at treating stimulant dependence and may aggravate the condition in some cases.

The relationships between symptom dimensions and dysphoria in schizophrenia

Previous studies have suggested that qualitatively distinct aspects of dysphoria (anxiety and depression) are related to specific dimension of schizophrenia symptomatology. Most of these studies used simple dimensions and dysphoria models, although finer distinctions could help defining specific relationships. This study examined the relationships of distinctive aspects of depression and anxiety (both state and trait) with symptom dimensions. Forty patients with a DSM-IV diagnosis of schizophrenia were assessed for symptoms (SAPS-SANS), trait and state anxiety (STAI) and depression (CDS). Symptoms ratings were summarized as dimensional scores according to a two-, three- or five-dimensional models proposed in the literature. The correlation analysis replicates previous observations that distinct aspects of dysphoria are associated with specific dimensions of schizophrenia, with the exception of disorganization. Moreover, controlling for intercorrelated variables revealed that schizophrenia and dysphoric symptoms might act in combination and/or through indirect links to contribute to illness expression. Our data further suggested that these associations may be best understood in terms of interactions between various processing biases alluded in the most recent cognitive accounts of schizophrenia symptoms.

Sleep habits in middle-aged, non-hospitalized men and women with schizophrenia: A comparison with healthy controls

Patients with schizophrenia may have sleep disorders even when clinically stable under antipsychotic treatments. To better understand this issue, we measured sleep characteristics between 1999 and 2003 in 150 outpatients diagnosed with Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) schizophrenia or schizoaffective disorder and 80 healthy controls using a sleep habits questionnaire. Comparisons between both groups were performed and multiple comparisons were Bonferroni corrected. Compared to healthy controls, patients with schizophrenia reported significantly increased sleep latency, time in bed, total sleep time and frequency of naps during weekdays and weekends along with normal sleep efficiency, sleep satisfaction, and feeling of restfulness in the morning. In conclusion, sleep-onset insomnia is a major, enduring disorder in middle-aged, non-hospitalized patients with schizophrenia that are otherwise clinically stable under antipsychotic and adjuvant medications. Noteworthy, these patients do not complain of sleep-maintenance insomnia but report increased sleep propensity and normal sleep satisfaction. These results may reflect circadian disturbances in schizophrenia, but objective laboratory investigations are needed to confirm subjective sleep reports.

Sex differences in memory processing in schizophrenia: An event-related potential (ERP) study

Recently, research has begun to examine sex differences in cognitive functions in schizophrenia and whether such sex differences reflect normal, exaggerated, or reversed sexual dimorphism. This study examined this question by using event-related potentials (ERPs). ERPs were recorded in a recognition memory task in 18 patients and 18 matched control subjects. On an early frontal component, the results show an interaction between sex and pathological condition that results in an apparent reversed sexual dimorphism. On mid-latency components, patients show no sex difference on a frontal component, but a difference on the posterior component, whereas healthy subjects show a reverse pattern. Finally, late components show sex difference in the same direction as healthy subjects. These results indicate that the influence of sex on the cognitive impairment in schizophrenia is not homogenous across the information-processing cascade.

Working memory and depressive symptoms in patients with schizophrenia and substance use disorders

Background. Substance abuse is highly prevalent in schizophrenia and it has been associated with negative consequences on the course of the pathology. Regarding cognition, the prevailing literature has produced mixed results. Some groups have reported greater cognitive impairments in dual diagnosis schizophrenia, while other groups have described the reverse. Objective. The current cross-sectional study sought to investigate the potential differences in psychiatric symptoms and cognition between schizophrenia patients with and without substance use disorders. Methods. Fifty-three schizophrenia patients were divided into two groups: with (n=30) and without (n=23) a substance use disorder (DSM-IV criteria). Psychiatric symptoms were measured with the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS). Psychomotor speed and spatial working memory were measured using Cambridge Neuropsychological Tests Automated Battery (CANTAB). Results. Patients in the dual diagnosis group displayed more severe depressive symptoms and poorer strategy during the working memory task. Conclusions. These results are in keeping with the prevailing literature describing negative consequences of substance abuse in schizophrenia. Substance abuse may exacerbate depressive symptoms and interfere with metacognition in schizophrenia.

Extrapyramidal Symptoms in Substance Abusers with and Without Schizophrenia and in Nonabusing Patients with Schizophrenia

Extrapyramidal symptoms (EPS) such as parkinsonism, dystonia, dyskinesia, and akathisia are conditions of impaired motor function, which are associated with chronic antipsychotic treatment in schizophrenia. In addition, EPS is often exacerbated by psychoactive substance (PAS) abuse, which is frequently observed in this population. Few studies, however, have investigated the contribution of PAS abuse on EPS in PAS‐abusers without comorbid psychosis. This study compared the occurrence of EPS in outpatient schizophrenia patients with (DD group; n= 36) and without PAS abuse (SCZ group; n = 41) as well as in nonschizophrenia PAS abusers undergoing detoxification [substance use disorder (SUD) group; n = 38]. Psychiatric symptoms were measured using the Positive and Negative Syndrome Scale and the Calgary Depression Scale for schizophrenia. Extrapyramidal symptoms were evaluated with the Extrapyramidal Symptoms Rating Scale and the Barnes Akathisia Scale. SUD diagnoses were complemented with urine drug screenings. We found that DD patients exhibited significantly more parkinsonism than SCZ patients. Our subanalyses revealed that cocaine and alcohol abuse/dependence was responsible for the increase in parkinsonism in DD patients. Additionally, we found that SUD individuals exhibited significantly more akathisia than SCZ patients. In these latter individuals, subanalyses revealed that alcohol and cannabis abuse/dependence was responsible for the increase in akathisia. Our results suggest that PAS abuse is a contributor to EPS in individuals with and without schizophrenia.