Inflammatory cytokine alterations in schizophrenia: a systematic quantitative review

BACKGROUND

Cytokines play an important role in infection and inflammation and are crucial mediators of the cross-talk between the brain and the immune system. Schizophrenia would be associated with an imbalance in inflammatory cytokines, leading to a decrease in Th1 and an increase in Th2 cytokine secretion. However, data published so far have been inconsistent. The primary objective of the present meta-analysis was to verify whether the cytokine imbalance hypothesis of schizophrenia is substantiated by evidence.

METHODS

Cross-sectional studies were included if they assessed in vivo plasma or serum cytokine concentrations and/or in vitro secretion of cytokines by peripheral blood leukocytes from schizophrenia patients and healthy volunteers.

RESULTS

Data from 62 studies involving a total sample size of 2298 schizophrenia patients and 1858 healthy volunteers remained for analysis. Ten cytokines were assessed, including the prototypic Th1 and Th2 cytokines gamma interferon (IFN-gamma) and interleukin 4 (IL-4) as well as IL-2, soluble IL-2 receptor (sIL-2R), IL-1beta, IL-1 receptor antagonist (IL-1RA), tumor necrosis factor-alpha (TNF-alpha), IL-6, soluble IL-6 receptor (sIL-6R), and IL-10. The results show that an increase occurs in in vivo IL-1RA, sIL-2R, and IL-6 and a decrease occurs in in vitro IL-2 in schizophrenia. No significant effect sizes were obtained for the other cytokines.

CONCLUSIONS

These findings provide the first evidence of establishment of an inflammatory syndrome in schizophrenia, which refutes the current hypothesis of a Th2 slant. Caveats are presented to data interpretation, including the role of stress and the effect of weight gain that develops in schizophrenia.

Neuropsychological change in early phase schizophrenia during 12 months of treatment with olanzapine, risperidone, or haloperidol. The Canadian Collaborative Group for research in schizophrenia

BACKGROUND

The purpose of this investigation was to test the efficacy of novel antipsychotic medications in the treatment of cognitive impairment in early phase schizophrenia.

METHODS

Sixty-five patients in this multicenter double-blind study were randomly assigned to olanzapine (5-20 mg), risperidone (4-10 mg), or haloperidol (5-20 mg). Standard measures of clinical and motor syndromes were administered, as well as a comprehensive battery of tests to assess (1) motor skills, (2) attention span, (3) verbal fluency and reasoning, (4) nonverbal fluency and construction, (5) executive skills, and (6) immediate recall at baseline and after 6, 30, and 54 weeks of treatment.

RESULTS

The general cognitive index derived from the 6 domain scores revealed a significantly greater benefit from treatment with olanzapine relative to haloperidol and olanzapine relative to risperidone, but no significant difference was shown between risperidone and haloperidol. The improvement related to olanzapine was apparent after 6 weeks and enhanced after 30 and 54 weeks of treatment. Exploratory within-group analyses of the 6 cognitive domains after a conservative Bonferroni adjustment revealed a significant improvement with olanzapine only on the immediate recall domain, and similar analyses of the 17 individual tests revealed a significant improvement with olanzapine only on the Hooper Visual Organization Test.

CONCLUSIONS

These data suggest that olanzapine has some superior cognitive benefits relative to haloperidol and risperidone. A larger sample replication study is necessary to confirm and generalize the observations of this study and begin evaluation of the implications of this change to cerebral function and quality of life for people with schizophrenia.

Clozapine alone versus clozapine and risperidone with refractory schizophrenia

BACKGROUND

The treatment of schizophrenia with multiple antipsychotic drugs is common, but the benefits and risks are not known.

METHODS

In a randomized, double-blind study, we evaluated patients with schizophrenia and a poor response to treatment with clozapine. The patients continued to take clozapine and were randomly assigned to receive eight weeks of daily augmentation with 3 mg of risperidone or with placebo. This course of treatment was followed by an optional 18 weeks of augmentation with risperidone. The primary outcome was reduction in the total score for severity of symptoms on the Positive and Negative Syndrome Scale (PANSS). The secondary outcomes included cognitive functioning.

RESULTS

A total of 68 patients were randomly assigned to treatment. In the double-blind phase, the mean total score for the severity of symptoms decreased from baseline to eight weeks in both the risperidone and the placebo groups. There was no statistically significant difference in symptomatic benefit between augmentation with risperidone and placebo: 9 of 34 patients receiving placebo and 6 of 34 receiving risperidone responded to treatment (P=0.38). The mean difference in the change in PANSS scores from baseline to eight weeks between those receiving risperidone and those receiving placebo was 0.1 (95 percent confidence interval, -7.3 to 7.0). The verbal working-memory index showed a small decline in the risperidone group and a small improvement in the placebo group (P=0.02 for the comparison between the two groups in the change from baseline). The increase in fasting blood glucose levels was mildly greater in the risperidone group than in the placebo group (16.2 vs. 1.8 mg per deciliter [0.90 vs. 0.10 mmol per liter], P=0.04). The incidence and severity of other side effects did not differ between the two groups.

CONCLUSIONS

In this short-term study, the addition of risperidone to clozapine did not improve symptoms in patients with severe schizophrenia. (ClinicalTrials.gov number, NCT00272584).

Sleep in untreated patients with schizophrenia: a meta-analysis

The present meta-analysis investigated the characteristics of sleep in patients with schizophrenia without neuroleptic treatment at the time of sleep recording. The 20 selected studies included 652 participants (321 patients with schizophrenia and 331 healthy subjects). Effect sizes were evaluated using d values for the following sleep variables: sleep latency (SL), total sleep time (TST), sleep efficiency index (SEI), total awake time (TAT), stage 2 percentage (S2%), stage 4 percentage, slow-wave-sleep percentage, rapid-eye-movement (REM) percentage, and REM latency. The initial meta-analysis revealed that patients with schizophrenia have the following sleep disorders: increased SL, decreased TST, and decreased SEI. A moderator analysis revealed that these sleep disorders were worse for the neuroleptic-withdrawal group relative to the never-treated group. However, only never-treated patients showed significantly increased TAT and diminished S2%. These results confirm that patients with schizophrenia have sleep disorders that are not necessarily a consequence of neuroleptic treatments, suggesting that sleep disorders are an intrinsic feature of schizophrenia. However, it must be noted that some sleep disorders may be amplified by residual effects of neuroleptic withdrawal, while others appear to be dampened by neuroleptic treatment.

The functional neuroanatomy of major depression: an fMRI study using an emotional activation paradigm

An important issue regarding the neural basis of major depression is whether the functional brain changes associated with the affect disturbance seen in this syndrome are similar to those that accompany transient sadness in normal subjects. To address this question, we carried out an fMRI study using an emotional activation paradigm. Brain activity associated with passive viewing of an emotionally laden film clip aimed at inducing a transient state of sadness was contrasted with that associated with passive viewing of an emotionally neutral film clip in patients suffering from unipolar depression and in normal control subjects. Results showed that transient sadness produced significant activation in the medial and inferior prefrontal cortices, the middle temporal cortex, the cerebellum and the caudate in both depressed and normal subjects. They also revealed that passive viewing of the emotionally laden film clip produced a significantly greater activation in the left medial prefrontal cortex and in the right cingulate gyrus in depressed patients than in normal control subjects. These findings suggest that these two cortical regions might be part of a neural network implicated in the pathophysiology of major depression. Taken together, these results strongly support the view that activation paradigms represent an extremely useful and powerful way of delineating the functional anatomy of the various symptoms that characterize major depression.

Exploring cognitive complaints in schizophrenia: the subjective scale to investigate cognition in schizophrenia

While it has become commonplace to test the various components of memory in schizophrenia with paper-and-pencil or in-lab tasks, very little data exist on the subjective complaints of patients regarding their memory. Few instruments have been designed to collect systematically the complaints of patients with schizophrenia. We present a work in progress on the Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS), a 21-item, Likert-type scale that is simple and easy to use. It allows a quantitative approach to the subjective and cognitive dimensions of schizophrenia. Stip constructed the scale based on a questionnaire covering several cognitive domains: memory (working memory, explicit long-term memory), attention (divided, distractibility, alertness, sustained), language, and praxia. We evaluated the psychometric properties of the SSTICS in a population of 114 French-speaking patients in Montreal. Patients were recruited in the community and assessed with the Structured Clinical Interview for DSM-III-R (SCID), the Positive and Negative Syndrome Scale (PANSS), and the Extrapyramidal Symptoms Rating Scale (ESRS). Cognition was measured using the Rey Auditory Verbal Learning Test (RAVLT) (long-term memory), Controlled Oral Word Association Test (verbal fluency), and Trails A and B. Preliminary analyses showed very good internal consistency for the global score (alpha=0.88), and alphas varying from 0.57 to 0.72 for the subscales. Stability over time was very good. The principal components analysis accounted for a multiple structure. Correlations between subjective scores and objective cognitive assessment were significant for several domains. Validation of the SSTICS needs to be completed through further exploration of the factorial structure and testing of the English version.

Computerized assessment of cognition in schizophrenia: Promises and pitfalls of CANTAB

Objective

Over the last decade, the Cambridge Neuropsychological Test Automated Battery (CANTAB), which comprises visuo-spatial tasks, has been utilized in cognitive studies of schizophrenia. A clear approach concerning the usage of CANTAB for the appraisal of neurocognitive dysfunction in schizophrenia is currently lacking.

Method

In this paper, we have first reviewed the overall applications of CANTAB and then evaluated methodological strengths and weaknesses of CANTAB as a neurocognitive battery for schizophrenia. We carried out a systematic search and assessment of studies where CANTAB was utilized to measure cognitive function in schizophrenia. We have also attempted to quantify the available data and perform a meta-analysis, but this approach turned out to be still premature.

Results

CANTAB has enabled researchers to highlight significant deficits affecting broad cognitive domains in schizophrenia, such as working memory, decision-making, attention, executive functions and visual memory. So far, the most consistent deficit observed with CANTAB testing has been attentional set-shifting, suggestive of fronto-striatal dysfunctions. In addition, preliminary evidence points towards the potential use of CANTAB to identify cognitive predictors of psychosocial functioning, to describe the relationships between symptoms and cognition, and to measure the impact of pharmacological agents on cognitive functioning.

Conclusion

CANTAB has been used successfully to highlight the range of visuo-spatial cognitive deficits in schizophrenia, producing similar results to those obtained with some traditional neuropsychological tests. Further studies validating the use of CANTAB following the standard set by Measurement And Treatment Research to Improve Cognition in Schizophrenia (MATRICS) are warranted.

Sleep architecture and its clinical correlates in first episode and neuroleptic-naive patients with schizophrenia

The goal of the present study was to characterize sleep organization in first episode and neuroleptic-naive patients with schizophrenia and to evaluate relationships between those sleep parameters and clinical symptoms. Eleven patients with acute schizophrenia never treated with neuroleptics were compared to 11 healthy controls. Sleep stages and phasic events (sleep spindles and rapid-eye-movements during REM sleep (REMs) were visually identified. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). Compared to controls, patients with schizophrenia had difficulty initiating sleep, decreased stage 4 duration, reduced rapid eye movement (REM) sleep latency, and normal sleep spindles and REMs densities. Positive symptoms correlated negatively with REM sleep latency. The BPRS total score correlated negatively with REM sleep duration and REMs density. The present results indicate that first episode and neuroleptic-naive patients with schizophrenia have difficulties initiating, but not maintaining, sleep. These results also confirm that the duration of stage 4 and REM sleep latency are reduced in first episode and neuroleptic-naive patients with schizophrenia. The fact that measures of REM sleep correlate with clinical scales of schizophrenia suggests that REM sleep physiology shares common substrates with symptoms of this disease.

Assessment of executive dysfunction during activities of daily living in schizophrenia

Many neuropsychological studies have described deficits of memory and executive functions in patients with schizophrenia, and the severity of these deficits seems to be determinant in predicting the community outcome of these patients [Schizophr. Bull. 26 (2000) 119]. However, neuropsychological evaluation does not provide valuable information about how the cognitive deficits directly affect daily living, that is, which cognitive deficit affects which behavior. The present study aimed at determining whether executive dysfunction in schizophrenia could be directly measured by analyzing three activities of daily living (ADL), in addition to assessing the ecological validity of commonly used neuropsychological tests. Within specific ADL (choosing a menu, shopping the ingredients, cooking a meal), the sequences of behaviors that have been performed by 27 control subjects and 27 patients with schizophrenia were both analyzed by using a preset optimal sequence of behavior. When compared with control subjects, patients with schizophrenia showed more omissions when choosing the menu, more sequencing and repetitions errors during the shopping task, and more planning, sequencing, repetition and omission errors during the cooking task. These behavioral errors correlated significantly with negative, but not with positive symptoms of the patients. Furthermore, they also correlated with the poor performances on executive neuropsychological tests, especially those sensitive to shifting and sequencing abilities, but not with memory tests. These results suggest that executive deficits in schizophrenia may specifically affect ADL and that such deficits can be quantitatively assessed with a behavioral scale of action sequences.

Contradictory cognitive capacities among substance-abusing patients with schizophrenia: a meta-analysis

Although a substance use disorder (SUD) is traditionally associated with psycho-bio-social impairments, recent investigations among persons with schizophrenia (Sz) generated divergent results. Certain persons with Sz+SUD might in fact present better social and cognitive functioning than persons with Sz without SUD. This meta-analysis was conducted to verify this counterintuitive possibility and to determine whether factors such as substance type, severity or nature of psychotic symptoms and age of the patients help discriminate these subgroups. Twenty-three studies met the inclusion criteria and data from 1807 persons with schizophrenia, with or without comorbid SUD, were available for analyses. As a group, persons with Sz+SUD did not obtain significantly higher scores at a Global Cognitive Index than persons with Sz without SUD, although they were better at the Trail Making Task and the speed processing domain. Secondary analyses showed the importance of considering intermediate factors, particularly the preferred substance used and the mean age. While consumption of alcohol was associated with a global cognitive scores similar to that of persons with Sz without an SUD and lower working memory capacities, preferential use of cannabis was instead associated with higher scores for problem solving and reasoning and visual memory. Age was inversely related to the size of the effects. It is concluded that previous mixed results obtained with cognitive evaluations of persons with Sz+SUD might reflect the heterogeneity of participants and that subgroups of patients might be defined on the basis of intermediate factors.

Cognitive predictors of psychosocial functioning outcome in schizophrenia: a follow-up study of subjects participating in a rehabilitation program

The aims of this prospective study were to explore in subjects with psychosis participating in a rehabilitation program whether cognitive performances at baseline predicted (i) psychosocial functioning over a 15-16 month follow-up; (ii) improvement in psychosocial functioning over the rehabilitation program. Visuo-spatial tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to assess cognitive performance in 55 subjects with schizophrenia spectrum disorders who completed a rehabilitation program. The Multnomah Community Ability Scale (MCAS) was used to measure dimensions of community functioning. One subscale of the Client's Assessment of Strengths, Interests, and Goals (CASIG) provided a measure of subjective quality of life (QoL). Improvement was defined as a 15% or more increase in psychosocial scores between baseline and follow-up. Worse baseline sustained attention predicted better self-rated quality of life, and better baseline visual memory predicted better community functioning over the rehabilitation follow-up period, in particular, higher autonomy in activities of daily living, and less physical and psychiatric symptoms that could interfere with rehabilitation. Baseline cognitive performances predicted community functioning improvement during the follow-up period: visual memory predicted improvement in daily living autonomy and in social competence; sustained attention predicted improvement in behavioral problems (such as medication compliance, collaboration with treatment providers or impulse control) and social competence; planning performances predicted improvement in social competence. These cognitive functions could be specifically targeted in a rehabilitation program aimed at enhancing functioning in those particular dimensions.

Are metabolic indices different between drug-naïve first-episode psychosis patients and healthy controls?

OBJECTIVE

To compare glucose and lipid metabolism parameters between drug-naïve first-episode psychosis (FEP) patients with a diagnosis of schizophrenia spectrum disorder and healthy controls matched for age, ethnicity, and gender.

METHOD

Baseline evaluations of fasting glucose and lipid metabolism parameters and the oral glucose tolerance test were performed with FEP patients (n=38), having no more than 10 days of cumulative exposure to antipsychotic medication, and normal community controls (n=36). Analysis of variance (ANOVA) was conducted to examine between group differences.

RESULTS

FEP patients did not show a higher prevalence of the precursors to diabetes (impaired fasting glucose, impaired glucose tolerance, insulin resistance), and no significant difference in beta-cell function or lipid profile measures, compared to healthy controls. FEP patients showed a higher waist to hip ratio compared to controls.

CONCLUSIONS

FEP patients having a schizophrenia spectrum disorder do not differ from healthy controls, in their baseline measures of glucose and lipid metabolites, nor in the prevalence of diabetes or its precursors, before (or close to) the onset of antipsychotic treatment.

Evaluation of a cognitive-behavioural program for the management of chronic tic and habit disorders

The aim was to evaluate the efficacy of a manualized cognitive-behavioural program based on habit reversal for the management of chronic tic disorder (CTD) and habit disorder (HD). Forty-seven CTD and 43 HD received a 4-month treatment program. Thirty-eight (22 CTD, 16 HD) were placed on a waitlist control group, which subsequently received treatment. The treatment approach combined awareness training, relaxation (including modification of a tension-producing style of action), and habit-reversal training, with more general cognitive restructuring of anticipations linked to ticcing. Sixty-five percent of completers reported between 75 and 100% control over the tic. At 2-year follow-up, 52% rated 75-100% control. There were also significant changes post-treatment in measures of self-esteem, anxiety, depression and style of planning action. Successful tic/habit modification was associated in CTD and HD groups with successful change in style of planning action. There were no consistent differences in any outcome measures between CTD and HD groups.

Selective serotonin reuptake inhibitor (SSRI) add-on therapy for the negative symptoms of schizophrenia: a meta-analysis

BACKGROUND

Negative symptoms are among the most chronic symptoms of schizophrenia. Even with the advent of atypical antipsychotic drugs, negative symptoms remain mostly refractory to treatment. It has been proposed that selective serotonin reuptake inhibitor (SSRI) augmentation therapy in schizophrenia could provide a greater relief of these symptoms. Published studies, however promising, have produced conflicting results.

OBJECTIVE

To overcome this discrepancy in results, we performed a meta-analysis of studies assessing SSRI add-on therapy for the negative symptoms of schizophrenia.

DATA SOURCES AND STUDY SELECTION

A search was performed using the computerized search engines PsycINFO, PubMed (MEDLINE), and Current Contents. Keywords used were schizophrenia and (for SSRI) sertraline, citalopram, paroxetine, fluoxetine, and fluvoxamine. Hand search of published review articles as well as cross-referencing were carried out, too. Pharmaceutical companies were also contacted. Studies were retained if (1) SSRI add-on therapy was compared with antipsychotic monotherapy among schizophrenia-spectrum disorder patients; (2) the clinical trial was randomized, double-blind, placebo-controlled with parallel-arm design; (3) negative symptoms were assessed with the Scale for the Assessment of Negative Symptoms or the Positive and Negative Syndrome Scale-negative subscale.

DATA EXTRACTION

With a consensus, authors (A.A.S. and S.P.) extracted and checked the data independently on the basis of predetermined exclusion and inclusion criteria. Effect size estimates were calculated using Comprehensive Meta-Analysis software.

DATA SYNTHESIS

Eleven studies responded to our inclusion criteria. Within a random-effects model, a nonsignificant composite effect size estimate for (end point) negative symptoms was obtained (N = 393; adjusted Hedges' g = 0.178; p = .191). However, when studies were divided according to severity of illness, a moderate and significant effect size emerged for the studies involving so-called "chronic patients" (N = 274; adjusted Hedges' g = 0.386; p = .014).

CONCLUSION

The current meta-analysis provides no global support for an improvement in negative symptoms with SSRI augmentation therapy in schizophrenia.

Self-assessed cognitive dysfunction and objective performance in outpatients with schizophrenia participating in a rehabilitation program

OBJECTIVE

To explore the pattern of associations between self-assessed and objective neuropsychological performance in a sample of outpatients with schizophrenia participating in a rehabilitation program.

METHOD

The Subjective Scale to Investigate Cognition in Schizophrenia (SSTICS) [Compr. Psychiatry 44 (2003) 331] was used to assess cognitive complaints in 73 subjects with schizophrenia. Visuo-spatial tests of the Cambridge Neuropsychological Test Automated Battery (CANTAB) [Cogn. Neuropsychiatry 3 (1998) 45] were administered as objective measures.

RESULTS

Cognitive complaints in several cognitive domains were mainly correlated with a true difficulty in memory. Higher SSTICS attention scores, i.e. increased complaints, were associated with poorer CANTAB explicit visual memory and planning performances. Higher SSTICS executive functioning scores were associated with poorer CANTAB explicit visual memory scores.

CONCLUSION

These findings suggest that outpatients with schizophrenia express some cognitive difficulties. However, the cognitive nature of these subjective complaints does not strictly correspond with objective performances. These results also suggest that theoretical constructs of cognitive functions do not always have ecological validity. Thus, subjective cognitive complaints should be taken into account in assessment of patient well-being, but cannot be used as a substitute to objective cognitive measures. The simultaneous use of subjective and objective measures of cognitive dysfunction may provide a more complete picture of individual rehabilitation targets in patients with schizophrenia.

A meta-analysis of negative symptoms in dual diagnosis schizophrenia

BACKGROUND

According to the self-medication hypothesis, schizophrenia patients would abuse psychoactive substances to get a relief from their negative symptoms. Studies testing the self-medication hypothesis in dual diagnosis (DD) schizophrenia have not been conclusive, with some studies showing that DD patients experience fewer negative symptoms, whereas other studies have failed to detect such differences. One potential confounding factor for this discrepancy lies in the diverse scales used to evaluate the negative symptoms. A systematic quantitative review of the literature using computerized search engines has been undertaken.

METHOD

Studies were retained in the analysis if: (i) they assessed negative symptoms using the SANS; (ii) groups of schizophrenia patients were divided according to substance use disorders (alcohol, amphetamines, cannabis, cocaine, hallucinogens, heroin and phencyclidine).

RESULTS

Attainable published studies were screened. According to our inclusion criteria, 18 possible studies emerged. Data from 11 studies were available for mathematical analysis. A moderate effect size (total n = 1135, 451 DD, 684 single diagnosis, adjusted Hedges' g = -0.470, p = 0.00001) was obtained, within a random-effect model, suggesting that DD patients experience fewer negative symptoms. Groups did not differ in age, sex, and positive/general psychopathology.

CONCLUSIONS

Using narrow criteria (e.g. SANS), the results of this meta-analysis show that schizophrenia patients with a substance use disorder experience fewer negative symptoms than abstinent schizophrenia patients. As such, these results suggest either that substance abuse relieves the negative symptoms of schizophrenia or that the patients with fewer negative symptoms would be more prone to substance use disorders.

Benefits and risks of antipsychotic polypharmacy: an evidence-based review of the literature

Combination antipsychotic prescription is an increasingly common practice in clinical psychiatry. This clinical practice is at odds with clinical guidelines promoting antipsychotic monotherapy. Moreover, there has been increased concern over the safety profile of atypical antipsychotics in the last 10-15 years. We reviewed the literature on antipsychotic combinations with a focus on safety and efficacy. Multiple electronic database searches were complemented by relevant bibliography cross-checking and expert discussions. The review showed a literature that is dominated by case reports and uncontrolled studies. Polypharmacy was unequally studied, with some recent combinations (i.e. clozapine and risperidone) being extensively, albeit inconclusively, studied and other more commonly used combinations (first- with second-generation agents) receiving little attention. From an evidence-based perspective, further trials of antipsychotic association of sufficient power to address safety issues are needed before recommending any antipsychotic combination. Particular weaknesses of the present literature are low number of participants, lack of adequate control of confounding variables, short duration of experimental follow-up and inadequate monitoring of potential adverse effects.

Predictors of quality of life in schizophrenia

The objective of this study was to clarify the relationships between socio-demographics, clinical characteristics, stressors, coping strategies, social support and quality of life (QOL) in 143 patients with a diagnosis of either schizophrenia or schizoaffective disorders. The research design is cross-sectional with repeated measures on the same subjects after a 6-month interval. A regression analysis generated a model that accounts for 50% of the variance in QOL at Time 1 and 43% at Time 2. The best predictors of QOL were two components of social support: attachment and reassurance of worth. Severity of daily hassles, the coping strategy of changing the situation, level of education and life-time hospitalization length were also related to QOL.

A laboratory study of sleep in Asperger's syndrome

Asperger's syndrome (AS) is a pervasive developmental disorder that may fall along the autistic spectrum. We compared the sleep of eight patients with AS with that of participants matched for age and gender. Patients with AS showed decreased sleep time in the first two-thirds of the night, increased number of shifts into REM sleep from a waking epoch, and all but one patient showed signs of REM sleep disruption. EEG sleep spindles were significantly decreased while K complexes and REM sleep rapid eye movements were normal. Three patients with AS, but none of the comparison participants, showed a pathological index of periodic leg movements in sleep. These observations show that sleep disorders are associated with AS and suggest that defective sleep control systems may be associated with the clinical picture of AS.

Pain perception in schizophrenia: no changes in diffuse noxious inhibitory controls (DNIC) but a lack of pain sensitization

BACKGROUND

Pain is a dynamic phenomenon resulting from the activity of both excitatory (e.g. sensitization) and inhibitory endogenous modulation systems. Preliminary experimental studies have shown diminished pain sensitivity in schizophrenia patients. The objective of the study was to investigate the role of excitatory and inhibitory systems on pain perception in schizophrenia.

METHODS

Participants were 23 patients with a schizophrenia-spectrum disorder (DSM-IV criteria) and 29 healthy volunteers, who did not differ in age, sex or ethnicity. Excitatory and inhibitory systems were elicited using a temporal summation test (Peltier thermode) administered before and after activation of the diffuse noxious inhibitory control (DNIC) by means of a cold-pressor test.

RESULTS

Time was a significant predictor of pain scores in controls, but not in patients. That is, pain ratings increased during the tonic thermal stimulation among controls but not in schizophrenia patients. When correlation coefficients (between time and pain ratings) for patients and controls were compared, the correlation coefficient emerged as significantly weaker in the schizophrenia group (Z=12.04; p=0.0001), suggesting a lack of sensitization in schizophrenia. DNIC was similar in magnitude in both patients and controls.

CONCLUSIONS

Diminished pain sensitivity in schizophrenia may be related to abnormal excitatory mechanisms, but not to DNIC. More studies are needed to better characterize the neurophysiological and neurochemical mechanisms involved in the lack of sensitization in schizophrenia.

A double-blind, placebo-controlled study of the effects of lithium on cognition in healthy subjects: mild and selective effects on learning

BACKGROUND

Several studies have shown cognitive impairment in short-term memory, long-term memory and psychomotor speed in bipolar patients taking lithium. The aim of the study was to look at the effect of lithium in normal subjects (N=30) taking lithium for 3 weeks. A comprehensive battery was used to assess attention and memory.

METHODS

Subjects were randomized to double-blind treatment with either lithium (N=15) or placebo (N=15) for a 3-week period. Thirteen participants in the lithium group and 15 in the placebo group completed the study. The lithium and placebo were administered twice daily in doses varying from 1050 to 1950 mg (mean=1569 mg). The initial daily dose was calculated according to the Pepin formula to achieve a blood serum lithium level of about 0.8 mmol/l. Cognitive performance (attention, memory) was assessed in each subjects during three periods, i.e. at baseline, after 3 weeks of lithium or placebo, and 2 weeks after discontinuation of study medication.

RESULTS

In short-term memory tasks, the performance of subjects in the lithium group was worst 3 weeks after lithium treatment compared to 2 weeks after discontinuation. In long-term memory, a significantly higher number of words was recalled by the placebo group but not the lithium group.

CONCLUSIONS

Lithium may have an effect on learning when long-term explicit memory test are administered repeatedly. It means that the practice effect when a subject performs the same task several times is less in the lithium-treated group than in the placebo group. This practice effect is related to the learning of a task.

Internet Addiction, Hikikomori Syndrome, and the Prodromal Phase of Psychosis

Computers, video games, and technological devices are part of young people's everyday lives. Hikikomori is a Japanese word describing a condition that mainly affects adolescents or young adults who live isolated from the world, cloistered within their parents' homes, locked in their bedrooms for days, months, or even years on end, and refusing to communicate even with their family. These patients use the Internet profusely, and only venture out to deal with their most imperative bodily needs. Although first described in Japan, cases have been described from around the world. This is the first published report from Canada. The disorder shares characteristics with prodromal psychosis, negative symptoms of schizophrenia, or Internet addiction, which are common differential or comorbid diagnoses. However, certain cases are not accompanied by a mental disorder. Psychotherapy is the treatment of choice although many cases are reluctant to present. The exact place of hikikomori in psychiatric nosology has yet to be determined. We searched Medline up to 12th May, 2015 supplemented by a hand search of the bibliographies of all retrieved articles. We used the following search terms: Hikikomori OR (prolonged AND social AND withdrawal). We found 97 potential papers. Of these 42 were in Japanese, and 1 in Korean. However, many of these were cited by subsequent English language papers that were included in the review. Following scrutiny of the titles and abstracts, 29 were judged to be relevant. Further research is needed to distinguish between primary and secondary hikikomori and establish whether this is a new diagnostic entity, or particular cultural or societal manifestations of established diagnoses.

Should we treat auditory hallucinations with repetitive transcranial magnetic stimulation? A metaanalysis

OBJECTIVE

Abnormal activations of neural networks implicated in auditory stimuli processing are hypothesized to generate auditory hallucinations (AH) in schizophrenia spectrum disorders. Because repetitive transcranial magnetic stimulation (rTMS) has the potential to modulate neural network activity, several studies have explored its use in treating medication-resistant AH, with mixed results in small-to-medium patient samples. Our aim is to apply a metaanalytic approach to exploring the efficacy of rTMS in treating medication-resistant AH.

METHOD

A search of the electronic databases for studies comparing low-frequency (1 Hz) rTMS over the left temporoparietal cortex to sham stimulation in patients suffering from medication- resistant AH was performed. Our search was completed by cross-referencing the articles, searching the Current Controlled Trials website, and direct contact with relevant researchers.

RESULTS

From 265 possible abstracts, 6 parallel-arm, double-blind placebo-controlled and 4 crossover controlled trials, all randomized, matched the inclusion and exclusion criteria (n = 232). The primary outcome measure (effect of active treatment on AH at the end of the treatment) was tested with a random effect model and reached a significant homogeneous ES estimate (Hedges' g = 0.514; P = 0.001; 95CI%, 0.225 to 0.804; Q = 13.022; P = 0.162).

CONCLUSIONS

We found that low-frequency rTMS over the left temporoparietal cortex has a medium ES action on medication-resistant AH. This result has implications for understanding the pathophysiology of psychotic symptoms (specifically AH) and supports the use of rTMS as a complementary treatment approach in patients suffering from treatment-resistant AH.

On the trail of a cognitive enhancer for the treatment of schizophrenia

The aim of this critical review is to address that the study of cognition and antipsychotics is not always driven by logic and that research into real pro-cognitive drug treatments must be guided by a better understanding of the biochemical mechanisms underlying cognitive processes and deficits. Many studies have established that typical neuroleptic drugs do not improve cognitive impairment. Atypical antipsychotics improve cognition, but the pattern of improvement differs from drug to drug. Diminished cholinergic activity has been associated with memory impairments. Why atypical drugs improve aspects of cognition might lie in their ability to increase dopamine and acetylcholine in the prefrontal cortex. An optimum amount of dopamine activity in the prefrontal cortex is critical for cognitive functioning. Another mechanism is related to procedural learning, and would explain the quality of the practice during repeated evaluations with atypical antipsychotics due to a more balanced blockage of D2 receptors. Laboratory studies have shown that clozapine, ziprasidone, olanzapine, and risperidone all selectively increase acetylcholine release in the prefrontal cortex, whereas this is not true for haloperidol and thioridazine. A few studies have suggested that cholinomimetics or AChE inhibitors can improve memory functions not only in Alzheimer's disease but also in other pathologies. Some studies support the role of decreased cholinergic activity in the cognitive deficits while others demonstrate that decreased choline acetyltransferase activity is related to deterioration in cognitive performance in schizophrenia. Overall, results suggest the hypothesis that the cholinergic system is involved in the cognitive dysfunctions observed in schizophrenia and that increased cholinergic activity may improve these impairments. Furthermore, a dysfunction of glutamatergic neurotransmission could play a key role in cognitive deficits associated with schizophrenia. Further meta-analysis of various clinical trials in this field is required to account for matters on the grounds of evidence-based medicine.

The effect of risperidone on cognition in patients with schizophrenia

OBJECTIVE

To evaluate the effect of risperidone on cognitive functions after both 6 weeks and 6 months of treatment and to determine whether any improvement on neuropsychological function relates to improvement in psychopathology.

METHOD

Patients' psychiatric and extrapyramidal symptoms were assessed while they were receiving classical neuroleptic treatment and adjunctive medications. Patients were then reassessed after changing to a new treatment of risperidone.

RESULTS

During treatment with risperidone, schizophrenic patients displayed improved performance mainly on attentional components, specifically, selective attention and alertness.

CONCLUSION

In patients who were given risperidone, there was a positive correlation between improvement in psychopathology and improvement in cognitive tests of explicit memory and alertness.