Biomedical subjects

Pierre Lalonde

Publications and source records attributed to Pierre Lalonde.

At least 19 recordsLinked to original sources

PubMed2006

Use of the process dissociation procedure to study the contextual effects on face recognition in schizophrenia: familiarity, associative recollection and discriminative recollection.

Contextual effects were explored in schizophrenia patients and paired comparison subjects during a long-term face recognition task. The objective was to investigate the contextual effects on face recognition by manipulating, in the same experiment, the perceptual context of the face (intrinsic vs. extrinsic) and the task context (inclusion vs. exclusion instructions). The situation was derived from the Jacoby's [Jacoby, L.L., 1991. A process dissociation framework: separating automatic from intentional uses of memory. Journal of Memory and Language 30, 513-541] process dissociation procedure. The results showed that schizophrenia patients (N=20) presented lower performances than healthy controls (N=20) in the inclusion but not in the exclusion task. This observation emphasizes the heterogeneity of recollection and suggests that the memory impairment in schizophrenia reflects an imbalance between two mechanisms. The first is a deficit in "associative recollection", i.e., the failure to use efficiently associative information. The other is an enhanced "discriminative recollection" that impedes their capacity to process information separately from its perceptual context. In addition, correlation with symptoms suggest that the former is expressed in the loosening of associations characteristic of disorganization symptoms, whereas the latter reflects the lack of flexibility or the contextualization bias related to psychotic symptoms, i.e., delusions and hallucinations.

Adult↗

PubMed2006

Are cholinergic enhancers beneficial for memory in schizophrenia? An event-related potentials (ERPs) study of rivastigmine add-on therapy in a crossover trial.

Studies have reported beneficial effects of cholinergic enhancers, e.g., rivastigmine, on memory in schizophrenia but others have not. Possibly, these discrepancies are related to the lack of specificity of the tests used. This study investigated the effect of rivastigmine on memory in schizophrenia using event-related potentials (ERPs). Eighteen patients treated with atypical antipsychotic received rivastigmine adjuvant therapy in a randomized, crossover design. They were assessed at baseline (T1) and on two subsequent occasions (T2 and T3), where one half of the subjects were taken rivastigmine and the other half not. ERPs were recorded during a recognition memory task on each session. Behavioral and ERP data were analyzed using mixed ANOVA models first at T1 to detect potential group differences and for the trial (T1-T2) to determine the influence of rivastigmine, i.e., sessionxgroup interactions. The results showed no group difference at T1 except a trend for one group to be less efficient than the other on RT measures. When controlling for this difference the results on the trial data showed a trend for a benefit of rivastigmine on the RT memory effect. ERP analysis revealed that rivastigmine affects the amplitudes of two components elicited within 150-300 ms over posterior (reduced N2b) and frontal sites (enhanced P2a). It also enhances the magnitude of the memory (old/new) effect on two later components over posterior (N400) and frontal sites (F-N400). These results suggest that rivastigmine improves selective attention by enhancing interference inhibition processes (P2a) and lowering the reactivity to incoming stimulus (N2b). It also improves the integration of information with knowledge (N400) and with its context (F-N400). Generally, this study showed that the beneficial effect of rivastigmine on memory is not unitary but rather comes from its action at different time points within information processing cascade.

Adult↗

PubMed2006

Including integrated psychological treatment as part of standard medical therapy for patients with schizophrenia: clinical outcomes.

To assess the clinical outcomes associated with the inclusion of Integrated Psychological Treatment (IPT) standard medical therapy in nine regular clinical settings, nine clinical teams integrated the complete IPT program (six hierarchically arranged subprograms) with their respective standard medical therapies for outpatients with schizophrenia. A total of 90 patients, young adults to long-term mentally ill patients, participated in the program. Patients were evaluated using standardized instruments at four time points: (1) prior to including the IPT program, (2) after the first three IPT subprograms, (3) at the end of IPT, and (4) 3 to 4 months post-IPT. The IPT program was associated with positive results. Patients improved in terms of overall symptoms, subjective experiences, cognitive and social functioning, and quality of life. IPT is one of the most up-to-date programs to address the rehabilitation needs of persons suffering from schizophrenia. Our experience in nine clinical settings suggests that IPT can successfully be included as part of standard medical therapy in the rehabilitation of patients with schizophrenia.

Adaptation, Psychological↗

PubMed2006

Health care resource use associated with integrated psychological treatment.

BACKGROUND: Mental health policies, advocating outpatient as well as community mental health care for the severely mentally ill, are aiming towards health system cost containment and patient quality of life. Programs with cognitive behavioral therapy, such as the Integrated Psychological Therapy (IPT), added to standard medical therapy for patients with schizophrenia have been associated with improved outcomes. A Quebec version of the IPT program was integrated in outpatient clinics and improvements were observed in overall symptoms, subjective experiences, cognitive and social functioning, and quality of life. In light of these results we deemed it relevant to describe the health system cost and patient resource use associated with the program. The costs related to IPT have not been previously reported and this study will elucidate on effective health services and budget allocation needed to include IPT. AIMS: To describe health care resource use and related costs associated with participating in an IPT program included as standard medical therapy in nine clinical settings. METHODS: A cohort of patients with schizophrenia participating in the IPT program were followed up to one year preceding the start of the program and concurrently until the end to compare the resource use and costs incurred by patients with schizophrenia during their participation. A health and social service system and patient perspective was adopted, and the medical and non-medical costs associated with the IPT program were measured. Valuation (2001 CDN dollars) was based on information provided by provincial billing systems. Statistical differences were assessed using the Wilcoxon signed-rank test. RESULTS: The IPT program induced a one time fixed cost (2347 dollars) for the training of mental health professionals and costs related to patient participation (1350 dollars). Our results show that there was an average decrease in health care system resource use per patient during the IPT program (26,133 dollars) as opposed to the preceding year (26,750 dollars). There was a significant decrease in the number of visits and in physician fees paid out to psychiatrists, the number of hospitalizations and related costs, and visits to the emergency department per patient during the IPT program as compared to the preceding year. No significant difference was observed in patient related costs which averaged 7295 dollars and 7537 dollars, before and during the IPT program, respectively. DISCUSSION: Although the IPT program induces a one time fixed cost for training, the integration of IPT, as part of an individualized standard medical therapy, is associated with a change from inpatient towards outpatient resource use with no significant increase in health system related costs. IMPLICATIONS FOR HEALTH CARE PROVISION AND USE: Given clinical and quality of life improvements, the findings suggest that offering IPT to more patients with severe mental illness may prove more cost beneficial by decreasing the health system related costs per user in the long term. IMPLICATIONS FOR FURTHER RESEARCH: Additional research is needed to examine in parallel the long-term clinical and cost impact of the IPT program in different clinical settings (young adults to long term mentally ill). This will elucidate to which patient population IPT is most cost-effective.

Adult↗

PubMed2005

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.

Adult↗

PubMed2005

Increased prevalence of schizophrenia spectrum disorders in relatives of neuroleptic-nonresponsive schizophrenic patients.

OBJECTIVE: It is suggested that schizophrenic patients who respond to neuroleptic medication and those who do not might differ with respect to their pathogenesis. In particular, it has been proposed that genetic factors may contribute to treatment response and/or outcome. In order to test this hypothesis, we compared the pattern of familial aggregation of schizophrenia related disorders in schizophrenic patients who are either responders (R) or nonresponders (NR) to typical neuroleptics. METHOD: R (n=36) or NR (n=35) patients to typical neuroleptics and healthy controls (n=63) were recruited. At least one key informant relative of each proband was interviewed blind as to the status of the proband using the Family Interview for Genetic Studies. Morbid risk for schizophrenia and cluster A personality disorders and family loading score for schizophrenia were examined in first- and second-degree relatives of these probands. RESULTS: First-degree relatives of NR patients were at a significantly higher risk for schizophrenia (MR=8.84), compared, respectively, to relatives of controls (MR=1.52) or relatives of R patients (MR=2.45). The same pattern was observed in second-degree relatives. Family loading score for schizophrenia in first- and second-degree relatives was significantly higher in NR compared to R patients. CONCLUSIONS: Schizophrenic patients who do not respond to typical neuroleptics may suffer from a more familial form of schizophrenia compared to patients who are responders.

Adult↗

PubMed2005

Cognitive discernible factors between schizophrenia and schizoaffective disorder.

BACKGROUND: Schizophrenia (SZ) and schizoaffective disorders (SA) are associated with cognitive deficits. Generally, a schizoaffective diagnosis is associated with better prognosis on the level of social integration. It is also well established that cognition is an important factor for good social outcome in schizophrenia. We hypothesized that, although patients suffering from SA share symptoms with SZ, they can be differentiated on the basis of neurocognitive function and that SA perform better in several domains. METHOD: Performances of two groups SA (N = 13) and SZ (N = 44) were compared on several visual-motor tasks using CANTAB [Motor Screening (MOT), Reaction Time (RTI), Paired Associates Learning Task (PAL), and Stockings of Cambridge items (SOC)]. The two groups were matched for symptom severity. ANOVA with repeated measures was employed to determine whether any difference in cognitive scores during a 2-year period was significantly related to the diagnostic status. RESULTS: A significant and durable difference was observed between SZ and SA on motor screening and explicit memory tests where SA performed better. CONCLUSION: Neurocognitive tests may be relevant for distinguishing schizoaffective from schizophrenia, chiefly via tests tapping into visuo-spatial and visuo-motor coordination abilities (e.g., paired associated learning and motor screening).

Adult↗

PubMed2005

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.

Adult↗

PubMed2005

Are there common mechanisms in sensation seeking and reality distortion in schizophrenia? A study using memory event-related potentials.

A growing literature suggests that the characteristics of sensation seeking and reality distortion expressed in schizophrenia share several mechanisms. In a previous study, the comparison of patients with high vs. low reality distortion using event-related potentials (ERPs) recorded in a recognition memory task for unfamiliar faces identified neural and cognitive anomalies specifically related to the expression of these symptoms. As a follow-up, this study investigated the ERP correlates of sensation seeking in schizophrenia using the same recognition memory protocol. ERPs have been recorded in controls (N=21) and schizophrenia patients separated into high (HSS; N=13) and low (LSS; N=17) scorers according to Zuckerman's Sensation Seeking Scale. The results show a reduced P2a that was found unrelated to reality distortion in the previous study of reality distortion. It identifies interference inhibition impairment as being specifically related to sensation seeking. On the other hand, HSS scorers display enhanced fronto-central and normal P600 effects also found in high reality distortion patients. These results indicate inappropriate context processing and mnemonic binding common to sensation seeking and reality distortion. LSS scorers also display a reduced temporal N300 similar to that found in low reality distortion patients. This anomaly could reflect the lower reactivity to emotionally significant stimuli that underlies anhedonia symptoms. Finally, the N400 effect and a late frontal effect are found in both HSS and LSS. Since they were unrelated to reality distortion, these indices have been related to basic aspects of schizophrenia, e.g., deficient knowledge integration, or other mechanisms, e.g. anxiety or impulsivity. In summary, the present study examines the strategy of investigating variables, such as temperamental characteristics, in addition to symptoms, to show how discrete impairments may contribute to the expression of the illness.

Adult↗

PubMed2005

Changes in the neuropsychological correlates of clinical dimensions between the acute and stable phase of schizophrenia.

This study was designed to investigate whether the neuropsychological correlates of the symptom dimensions of schizophrenia vary with the clinical state in patients followed from the acute to stable the phase of the illness. Fifteen patients were assessed for symptoms (SAPS-SANS) and undergone a complete neuropsychological assessment at two sessions. The first session (S1) was carried out within six days after admission, i.e., acute phase and the second (S2) at least two month after hospitalization, i.e., stable phase. The data were analyzed using stepwise regression models in which neuropsychological scores were in entered to predict each dimensional score. This analysis was applied on the S1 and S2 data as well as on the S2-S1 difference to assess the neuropsychological predictors of clinical changes. Generally, the results replicate the previous associations between neuropsychological and dimensional measures found in stable patients. In addition, this study shows if each dimension appears to rely on a key structure, symptom variations seems to involve changes in the spread of the dysfunction and/or changes in the connectivity between the key and other regions. The results also suggest that functional changes related to some symptoms dimensions occur to compensate for the dysfunction associated with other symptoms.

Acute Disease↗

PubMed2005

CANTAB explicit memory is less impaired in addicted schizophrenia patients.

It has been suggested that in order to sustain the lifestyle of substance abuse, addicted schizophrenia patients would have less negative symptoms, better social skills, and less cognitive impairments. Mounting evidence supports the first two assumptions, but data lack regarding cognition in dual diagnosis schizophrenia. Seventy-six schizophrenia outpatients (DSM-IV) were divided into two groups: with (n = 44) and without (n = 32) a substance use disorder. Motor speed and visuo-spatial explicit memory were investigated using CANTAB. As expected, dual diagnosis patients showed a better cognitive performance. Our results suggest either that substance abuse relieves the cognitive deficits of schizophrenia or that the patients with less cognitive deficits are more prone to substance abuse.

Adult↗

PubMed2005

[Implementation of the multi-site Integrated Psychological Treatment (IPT) program for people with schizophrenia. Elaboration of renewed version].

Brenner's Integrated Psychological Treatment (IPT) program (Brenner et al., 1992 ; Pomini et al., 1998), a cognitive-behavioural approach, was implemented in nine of Quebec's clinical settings that treat people with schizophrenia. A study allowed an evaluation of the IPT program in each location, with emphasis on the level of satisfaction of both participants and professionals, the program's strong points, and areas where improvements were needed. The results have shown that the implementation of the program has been successful in all nine clinical settings. Professionals and participants appreciated the IPT program not only for its hierarchic structure that considers the rehabilitation needs of people affected by schizophrenia, but also for its customised application framework, which allows a regular follow-up of a similar group of patients over the course of a one year period. As a result of this study, the modifications proposed and additions have enabled the creation of a Quebec version of the IPT program, which better achieves its objectives, particularly those relating to the maintenance and generalisation of social learning in the context of a participant's real-life situation.

Delivery of Health Care, Integrated↗

PubMed2004

The crucial role of sustained attention in community functioning in outpatients with schizophrenia.

The aim was to explore the pattern of associations between visual cognitive performance and community functioning in a sample of outpatients with schizophrenia participating in a rehabilitation program. Visuo-spatial tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to assess cognitive performances in 88 subjects. The Multnomah Community Ability Scale (MCAS) was used to measure dimensions of community functioning. Our results showed that the sustained attention score was significantly associated with the global community functioning score and with two specific dimensions: "adjustment to living" and "behavioral problems". No association was found between other cognitive indices and MCAS scores. Since the sustained attention task mainly involves the executive component of working memory, these findings suggest that attentional control processes are limiting factors for community functioning in schizophrenia outpatients. Measures of such processes could serve as key indices of disability in clinical practice. Attention and working memory training may be helpful to improve community functioning in subjects with schizophrenia.

Adult↗

PubMed2004

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.

Adult↗

PubMed2003

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.

Adult↗

PubMed2003

Dopamine beta-hydroxylase (DBH) gene and schizophrenia phenotypic variability: a genetic association study.

Recently, two polymorphisms (DBH5'-Ins/del and DBH 444 g/a) of the Dopamine Beta Hydroxylase (DBH) gene were isolated, and one haplotype (Del-a) was found to be associated with low DBH activity and cocaine-induced paranoia. The purpose of this study is to test for association between these two polymorphisms and schizophrenia or its phenotypic variability with respect to neuroleptic therapeutic response and symptom profile. Allelic and haplotype distributions of these two polymorphisms were compared between two groups of schizophrenic patients (excellent neuroleptic-responders; R, n = 42 and non-responders; NR, n = 64), and one group of healthy volunteers (n = 120). The "Del" and "a" alleles were in positive linkage disequilibrium. No allelic or genotype differences in the distribution of these two polymorphisms were observed between patients and controls. However, The Del-a haplotype was significantly more common in NR patients, and the mean total BPRS score was significantly higher in the group of patients with the Del-a compared to those without the Del-a haplotype. These results suggest that the DBH gene is not a causative factor in schizophrenia but that it may be a modulator of psychotic symptoms, severity of the disorder and therapeutic response to neuroleptic drugs.

Adolescent↗

PubMed2003

Evaluating antipsychotic medications: predictors of clinical effectiveness. Report of an expert review panel on efficacy and effectiveness.

Over the course of the last decade, atypical antipsychotic medications (olanzapine, quetiapine, and risperidone) have become first-line choices for acute and maintenance treatment for schizophrenia. In numerous cases, these antipsychotics have replaced typical neuroleptics, which are associated with a high incidence of adverse effects, particularly parkinsonism and tardive dyskinesia. Each pharmaceutical company that produces an atypical antipsychotic has supported numerous studies in an attempt to demonstrate the superiority of its agent compared with its competitors. Many of these studies are, unfortunately, too brief in duration, given that schizophrenia and the other psychoses require long-term treatment. Nevertheless, those studies have yielded interesting and evidence-based data. The clinician cannot, however, rely entirely on data from studies. Clinical experience, which allows clinicians to follow patients for prolonged periods of time, is also important in choosing an antipsychotic medication. This article takes the refreshing approach of considering both of these aspects to guide more appropriate prescription of the atypical antipsychotics.

Antipsychotic Agents↗

PubMed2002

Neuropsychological impairments in neuroleptic-responder vs. -nonresponder schizophrenic patients and healthy volunteers.

To determine whether two groups of schizophrenic patients representing the two extremes of the neuroleptic response-spectrum (consistent responders vs. consistent nonresponders) differ with respect to their neuropsychological profile. Neuroleptic-responder (R; n=36) and -nonresponder (NR; n=39) schizophrenic patients were recruited according to a priori defined criteria of responsiveness to typical neuroleptics. Seven neuropsychological domains were assessed and compared between groups: attention-vigilance, abstraction-flexibility, spatial organization, visual-motor processing, visual memory, verbal abilities, and verbal memory and learning. All measures were standardized using the scores of 36 healthy volunteers. NR schizophrenic patients performed worse in all neuropsychological domains compared to normal controls and R schizophrenic patients. However, only performances on visual memory, verbal abilities, and verbal memory and learning were significantly poorer in NR compared to R patients. Only the latter domain significantly differentiated NR patients from the other two groups. R patients performed at an intermediate level in all domains. This report of differences in neuropsychological profile between neuroleptic-responder and -nonresponder schizophrenic patients adds to the growing evidence supporting the value of distinguishing schizophrenic patients on the basis of their therapeutic response to neuroleptics.

Adult↗