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Dive into the research topics where Laurent Holzer is active.

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Featured researches published by Laurent Holzer.


Schizophrenia Research | 2007

Detection of cognitive impairment with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in adolescents with psychotic symptomatology

Laurent Holzer; Léonie Chinet; Laure Jaugey; Bernard Plancherel; Caroline Sofia; Olivier Halfon; Christopher Randolph

Cognitive impairment has been identified in the early phase of schizophrenia spectrum disorders, and is a major contributor to disease-related disability. While screening tools assessing cognitive impairment have been validated for adult schizophrenic populations, there is a need for brief, easily administered, standardized instruments that provide clinically relevant information for adolescents. This study examines the utility of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in identifying and quantifying neurocognitive impairment in adolescents with schizophrenia spectrum disorders and other serious psychiatric illnesses. 112 adolescents, including 32 healthy subjects and 80 patients, were administered the RBANS. Patients with psychotic disorders demonstrated significant impairment on the RBANS total score compared to patients with other disorders and healthy controls, but this impairment appeared somewhat less severe than is typically reported for in adult patients with schizophrenia on this measure. The RBANS appears to be sensitive in the detection of neurocognitive impairment in a psychiatric population of adolescents with psychotic symptomatology, and may therefore have utility as a clinical screening instrument and/or neurocognitive outcome measure in this population.


JAMA Psychiatry | 2013

Influence of CRTC1 Polymorphisms on Body Mass Index and Fat Mass in Psychiatric Patients and the General Adult Population.

Eva Choong; Lina Quteineh; Jean-René Cardinaux; Mehdi Gholam-Rezaee; Frederik Vandenberghe; Maria Dobrinas; Guido Bondolfi; Manuela Ioana Etter; Laurent Holzer; Pierre J. Magistretti; Armin von Gunten; Martin Preisig; Peter Vollenweider; Jacques S. Beckmann; François P. Pralong; Gérard Waeber; Zoltán Kutalik; Philippe Conus; Murielle Bochud; Chin B. Eap

IMPORTANCE There is a high prevalence of obesity in psychiatric patients, possibly leading to metabolic complications and reducing life expectancy. The CREB-regulated transcription coactivator 1 (CRTC1) gene is involved in energy balance and obesity in animal models, but its role in human obesity is unknown. OBJECTIVE To determine whether polymorphisms within the CRTC1 gene are associated with adiposity markers in psychiatric patients and the general population. DESIGN, SETTING, AND PARTICIPANTS Retrospective and prospective data analysis and population-based samples at Lausanne and Geneva university hospitals in Switzerland and a private clinic in Lausanne, Switzerland. The effect of 3 CRTC1 polymorphisms on body mass index (BMI) and/or fat mass was investigated in a discovery cohort of psychiatric outpatients taking weight gain-inducing psychotropic drugs (sample 1, n = 152). The CRTC1 variant that was significantly associated with BMI and survived Bonferroni corrections for multiple comparison was then replicated in 2 independent psychiatric samples (sample 2, n = 174 and sample 3, n = 118) and 2 white population-based samples (sample 4, n = 5338 and sample 5, n = 123,865). INTERVENTION Noninterventional studies. MAIN OUTCOME AND MEASURE Difference in BMI and/or fat mass between CRTC1 genotype groups. RESULTS Among the CRTC1 variants tested in the first psychiatric sample, only rs3746266A>G was associated with BMI (P(adjusted) = .003). In the 3 psychiatric samples, carriers of the rs3746266 G allele had a lower BMI than noncarriers (AA genotype) (sample 1, P = .001; sample 2, P = .05; and sample 3, P = .0003). In the combined analysis, excluding patients taking other weight gain-inducing drugs, G allele carriers (n = 98) had a 1.81-kg/m² lower BMI than noncarriers (n = 226; P < .0001). The strongest association was observed in women younger than 45 years, with a 3.87-kg/m² lower BMI in G allele carriers (n = 25) compared with noncarriers (n = 48; P < .0001), explaining 9% of BMI variance. In the population-based samples, the T allele of rs6510997C>T (a proxy of the rs3746266 G allele; r² = 0.7) was associated with lower BMI (sample 5, n = 123,865; P = .01) and fat mass (sample 4, n = 5338; P = .03). The strongest association with fat mass was observed in premenopausal women (n = 1192; P = .02). CONCLUSIONS AND RELEVANCE These findings suggest that CRTC1 contributes to the genetics of human obesity in psychiatric patients and the general population. Identification of high-risk subjects could contribute to a better individualization of the pharmacological treatment in psychiatry.


Behavioural and Cognitive Psychotherapy | 2014

A Randomized Controlled Trial of the Effectiveness of Computer-Assisted Cognitive Remediation (CACR) in Adolescents with Psychosis or at High Risk of Psychosis

Laurent Holzer; Sébastien Urben; Christina Moses Passini; Laure Jaugey; Michael H. Herzog; Olivier Halfon; Sandrine Pihet

BACKGROUND Computer assisted cognitive remediation (CACR) was demonstrated to be efficient in improving cognitive deficits in adults with psychosis. However, scarce studies explored the outcome of CACR in adolescents with psychosis or at high risk. AIMS To investigate the effectiveness of a computer-assisted cognitive remediation (CACR) program in adolescents with psychosis or at high risk. METHOD Intention to treat analyses included 32 adolescents who participated in a blinded 8-week randomized controlled trial of CACR treatment compared to computer games (CG). Cognitive abilities, symptoms and psychosocial functioning were assessed at baseline and posttreatment. RESULTS Improvement in visuospatial abilities was significantly greater in the CACR group than in CG. Other cognitive functions, psychotic symptoms and psychosocial functioning improved significantly, but at similar rates, in the two groups. CONCLUSION CACR can be successfully administered in this population; it proved to be effective over and above CG for the most intensively trained cognitive ability.


Journal of Clinical Psychopharmacology | 2006

Risperidone-induced Symptomatic Hyperprolactinaemia in Adolescents

Laurent Holzer; Chin B. Eap

Studies performed in adult patients unambiguously demonstrate a marked effect of risperidone on prolactin blood levels, with possible clinical effects related to hyperprolactinemia, such as gynecomastia and galactorrhea. However, the largest study performed in children and adolescents showed a weak effect of risperidone on prolactin concentrations during short-term treatment and a negligible effect during long-term treatment, which was probably because of the relatively low dosages of risperidone used [~0.04 mg/(kg · d)]. Among the 10 psychotic adolescents treated with risperidone in our unit, we had 3 cases of gynecomastia in 3 male patients and 2 cases of galactorrhea in 2 female patients. The prolactin blood levels in these cases and in 3 other patients without apparent prolactin-related side effects were all above the normal range (median, 59 ng/mL; range, 30-123 ng/mL). Thus, risperidone administered to adolescents at doses commonly used for the treatment of psychotic symptoms can strongly increase prolactin levels, with clinical consequences such as gynecomastia and/or galactorrhea. Given that the long-term effects of antipsychotic drug-induced hyperprolactinemia are not well documented, especially regarding osteopenia, infertility, growth, and pubertal delay, risperidone should be administered with caution to children and adolescents. (J Clin Psychopharmacol 2006;26:167-171)


Substance Use & Misuse | 2005

Adolescent Substance-Use Assessment: Methodological Issues in the Use of the ADAD (Adolescent Drug Abuse Diagnosis)

Léonie Chinet; Bernard Plancherel; Monique Bolognini; Laurent Holzer; Olivier Halfon

THis article has been retracted.


Journal of Clinical and Experimental Neuropsychology | 2009

Deteriorated visual backward masking in the shine-through effect in adolescents with psychosis

Laurent Holzer; Laure Jaugey; Léonie Chinet; Michael H. Herzog

Visual backward masking is a reliable and widely used tool in schizophrenia research. Whereas many studies have shown masking deficits in adult patients, there are only very few studies with adolescents with psychosis—and with controversial results. Masking deficits of adolescents are of primary interest because they are not caused by long-term suffering from the disease and severe medication. We investigated 15 adolescents with psychosis and 19 age-matched controls in the shine-through backward masking paradigm for which strong performance deficits were shown previously in adult schizophrenic patients and their relatives. Adolescents with psychosis were strongly impaired in the shine-through effect compared to controls. This result adds further evidence that backward masking is an endophenotype of schizophrenia.


Psychiatry Research-neuroimaging | 2014

The French adaptation of the Health of the Nation Outcome Scale for Children and Adolescents Self-Rated Form (F-HoNOSCA-SR): Validation and clinical routine use

Sébastien Urben; Vanessa Baier; Gregory Mantzouranis; Jeannette Schwery; Chantal Mahi; Swen Courosse; Boris Guignet; Olivier Halfon; Laurent Holzer

The current study aimed to explore the validity of an adaptation into French of the self-rated form of the Health of the Nation Outcome Scales for Children and Adolescents (F-HoNOSCA-SR) and to test its usefulness in a clinical routine use. One hundred and twenty nine patients, admitted into two inpatient units, were asked to participate in the study. One hundred and seven patients filled out the F-HoNOSCA-SR (for a subsample (N=17): at two occasions, one week apart) and the strengths and difficulties questionnaire (SDQ). In addition, the clinician rated the clinician-rated form of the HoNOSCA (HoNOSCA-CR, N=82). The reliability (assessed with split-half coefficient, item response theory (IRT) models and intraclass correlations (ICC) between the two occasions) revealed that the F-HoNSOCA-SR provides reliable measures. The concurrent validity assessed by correlating the F-HoNOSCA-SR and the SDQ revealed a good convergent validity of the instrument. The relationship analyses between the F-HoNOSCA-SR and the HoNOSCA-CR revealed weak but significant correlations. The comparison between the F-HoNOSCA-SR and the HoNOSCA-CR with paired sample t-tests revealed a higher score for the self-rated version. The F-HoNSOCA-SR was reported to provide reliable measures. In addition, it allows us to measure complementary information when used together with the HoNOSCA-CR.


Child Psychiatry & Human Development | 2015

Predictors and Moderators of Clinical Outcomes in Adolescents with Severe Mental Disorders After an Assertive Community Treatment

Sébastien Urben; Vanessa Baier; Gregory Mantzouranis; Eva Pigois; Caroline Graap; Fabienne Dutoit; Mélanie Cherix-Parchet; Coralie Henz; Aymeric Faucherand; Esperanza Senent; Laurent Holzer

Previous studies have shown that stressful life events (SLEs), gender, social functioning and pretreatment severity are some of the predictors and/or moderators of treatment outcome in psychiatric care. The current study explored the effect of these predictors and moderators on the treatment outcome related to assertive community treatment (ACT) proposed to young people with severe mental disorders. 98 patients were assessed for externalizing and emotional difficulties, at admission and then at discharge of an ACT. Analyses revealed significant improvements in terms of symptomatology. In particular, regression analyses showed that pretreatment severity is a significant predictor of the outcome on emotional symptoms and is moderated by SLE on the outcome on externalizing symptoms. Furthermore, higher social functioning proved to predict better outcome on externalizing symptoms. Our results further evidence that these factors can explain inter-individual differences in outcome related to ACT. The theoretical and clinical implications of these results are discussed.


Psychotherapy Research | 2013

Treatment motivation in adolescents with psychosis or at high risk: determinants and impact on improvements in symptoms and cognitive functioning, preliminary results.

Sandrine Pihet; Christina Moses Passini; Laurent Holzer

Abstract Low motivation is frequent in chronic disorders such as psychosis and may limit treatment efficacy. Although some evidence supports this view in adults, few studies so far have focused on adolescents. We assessed the impact of baseline symptoms, cognitive deficits and cognitive treatment characteristics on treatment motivation (TM), and examined whether TM affected treatment outcome. Twenty-eight adolescents with psychotic disorders participated in 16 sessions of computerized cognitive remediation or games. TM was assessed for each session. Lower TM was predicted by more severe symptoms at baseline, and was associated with smaller improvements in symptoms and both cognitive and psychosocial functioning at the end of the intervention. Experiencing success in the treatment exercises enhanced TM in all patients.


Archives of Psychiatric Nursing | 2016

Timing of Clinical Improvement in Assertive Community Treatment for Adolescents: A Pilot Naturalistic Observational Study.

Sébastien Urben; Gregory Mantzouranis; Vanessa Baier; Olivier Halfon; Eva Villard; Laurent Holzer

Assertive community treatment (ACT) reduces symptoms and enhances social integration for adolescents with severe psychiatric disorders (Baier, Favrod, Ferrari, Koch, & Holzer, 2013; Rowland et al., 2005; Schley et al., 2008). In our practice, the duration of ACT rarely exceeds 12 months. However, the question of the necessary timing to draw therapeutic benefits is largely unanswered. Therefore, the purpose of this pilot study is to provide foundational guidance about the necessary duration of ACT to achieve therapeutic benefit.

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Chin B. Eap

University of Lausanne

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Michael H. Herzog

École Polytechnique Fédérale de Lausanne

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