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Dive into the research topics where Michael Liebrenz is active.

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Featured researches published by Michael Liebrenz.


World Journal of Biological Psychiatry | 2009

Repeated intravenous ketamine therapy in a patient with treatment-resistant major depression

Michael Liebrenz; Rudolf Stohler; Alain Borgeat

Background: The intravenous administration of ketamine, an N-methyl-d-aspartate receptor antagonist, results in a great improvement of depression symptoms, but it is not clear for how long. This single-case trial was conducted to explore the duration of improvement and the effects of a second administration on the clinical outcome. Methods: In an open label trial, a 55-year-old male patient with treatment-resistant major depression and a co-occurring alcohol and benzodiazepine dependence received two intravenous infusions of 0.5 mg/kg ketamine over the course of 6 weeks. Depression severity was assessed by means of a weekly clinical interview, the 21-item Hamilton Depression Rating Scale (HDRS), and the 21-item Beck Depression Inventory (BDI). Results: The first ketamine infusion lead to a pronounced improvement of symptoms, peaking on the second day post infusion (HDRS −56.6%, BDI −65.4%). Positive effects started fading by day 7, reaching baseline by day 35. The second infusion was less efficacious: HDRS and BDI were reduced by 43 and 35%, respectively, and returned to baseline by day 7. Conclusion: In this patient with a co-occurring substance use disorder, repeated administrations of ketamine produced positive results. Since the second application has been less efficacious, doses and schedule of administrations need to be further investigated.


PLOS ONE | 2015

High-Dose Benzodiazepine Dependence: A Qualitative Study of Patients’ Perceptions on Initiation, Reasons for Use, and Obtainment

Michael Liebrenz; Marcel André Schneider; Anna Buadze; Marie-Therese Gehring; Anish Dube; Carlo Caflisch

Background High-dose benzodiazepine (BZD) dependence is associated with a wide variety of negative health consequences. Affected individuals are reported to suffer from severe mental disorders and are often unable to achieve long-term abstinence via recommended discontinuation strategies. Although it is increasingly understood that treatment interventions should take subjective experiences and beliefs into account, the perceptions of this group of individuals remain under-investigated. Methods We conducted an exploratory qualitative study with 41 adult subjects meeting criteria for (high-dose) BZD-dependence, as defined by ICD-10. One-on-one in-depth interviews allowed for an exploration of this group’s views on the reasons behind their initial and then continued use of BZDs, as well as their procurement strategies. Mayring’s qualitative content analysis was used to evaluate our data. Results In this sample, all participants had developed explanatory models for why they began using BZDs. We identified a multitude of reasons that we grouped into four broad categories, as explaining continued BZD use: (1) to cope with symptoms of psychological distress or mental disorder other than substance use, (2) to manage symptoms of physical or psychological discomfort associated with somatic disorder, (3) to alleviate symptoms of substance-related disorders, and (4) for recreational purposes, that is, sensation-seeking and other social reasons. Subjects often considered BZDs less dangerous than other substances and associated their use more often with harm reduction than as recreational. Specific obtainment strategies varied widely: the majority of participants oscillated between legal and illegal methods, often relying on the black market when faced with treatment termination. Conclusions Irrespective of comorbidity, participants expressed a clear preference for medically related explanatory models for their BZD use. We therefore suggest that clinicians consider patients’ motives for long-term, high-dose BZD use when formulating treatment plans for this patient group, especially since it is known that individuals are more compliant with approaches they perceive to be manageable, tolerable, and effective.


Journal of Affective Disorders | 2014

Temperamental differences between bipolar disorder, borderline personality disorder, and attention deficit/hyperactivity disorder: Some implications for their diagnostic validity

Dominique Eich; Alex Gamma; Tina Malti; Marianne Vogt Wehrli; Michael Liebrenz; Erich Seifritz; Jiri Modestin

BACKGROUND The relationship between borderline personality disorder (BPD), bipolar disorder (BD), and attention deficit/hyperactivity disorder (ADHD) requires further elucidation. METHODS Seventy-four adult psychiatric in- and out-patients, each of them having received one of these diagnoses on clinical assessment, were interviewed and compared in terms of diagnostic overlap, age and sex distribution, comorbid substance, anxiety and eating disorders, and affective temperament. RESULTS Diagnostic overlap within the three disorders was 54%. Comorbidity patterns and gender ratio did not differ. The disorders showed very similar levels of cyclothymia. LIMITATIONS Sample size was small and only a limited number of validators were tested. CONCLUSIONS The similar extent of cyclothymic temperament suggests mood lability as a common denominator of BPD, BD, and ADHD.


BMC Psychiatry | 2014

Adult attention-deficit/hyperactivity disorder and nicotine use: a qualitative study of patient perceptions

Michael Liebrenz; Anja Frei; Carl Erik Fisher; Alex Gamma; Anna Buadze; Dominique Eich

BackgroundAdult Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with high rates of comorbid substance use disorders, and cigarette smoking has a particularly high prevalence in this population. However, there is an ongoing debate as to whether this tobacco use is an attempt at “self-medication” or due to behavioral disinhibition. There is a surprising lack of qualitative studies that investigate the subjective perceptions of adults with ADHD regarding cigarette smoking. The present study was designed to fill this gap in the literature.MethodsWe recruited twelve adult patients with ADHD and comorbid tobacco use from our ADHD consultation service, an outpatient facility of the Zurich University Psychiatric Hospital. Subjects were interviewed using qualitative methodology, and Mayrings qualitative content analysis was used to evaluate findings.ResultsWe identified two explanatory models linking ADHD and tobacco use: smoking as an attempt at self-medication and “smoking as a social behavior”. On one hand, subjects considered tobacco a therapeutic aid, reporting positive effects on “inner tension” and cognitive function, and noted possible antidepressant properties as well. On the other hand, subjects considered smoking to enhance social functioning and to have a positive impact on interpersonal relationships. The majority believed that stimulant medications offered only a transient decrease in patterns of tobacco use because their ability to reduce nicotine cravings wore off quickly. Others believed that stimulants had no effect or even reinforced cigarette use.ConclusionsParticipants had different views about the link between cigarette smoking and ADHD. While the majority thought of nicotine as a sort of therapy, viewing smoking as a way to self-medicate symptoms of ADHD, motivations for nicotine use were also related to self-image, desire to belong to a peer-group, and a drive to undermine perceived social norms. Ultimately, these findings can be used by clinicians to improve treatment alliance and collaboration.


Journal of The International Neuropsychological Society | 2014

Predictors for Improvement of Problem-Solving during Cognitive Remediation for Patients with Schizophrenia

Katlehn Rodewald; Daniel V. Holt; Mirjam Rentrop; Daniela Roesch-Ely; Michael Liebrenz; Joachim Funke; Matthias Weisbrod; Stefan Kaiser

Cognitive remediation is a promising pathway for ameliorating cognitive impairment of patients with schizophrenia. Here, we investigate predictors of improvement in problem-solving ability for two different types of cognitive remediation - specific problem-solving training and training of basic cognition. For this purpose we conducted a re-analysis of a randomized controlled trial comparing these two training approaches. The main outcome measure was improvement in problem-solving performance. Correlational analyses were used to assess the contribution of clinical, cognitive and training-related predictors. In the problem-solving training group, impaired pre-training planning ability was associated with stronger improvement. In contrast, in the basic cognition training group antipsychotic medication dose emerged as a negative predictor. These results demonstrate that predictors for successful cognitive remediation depend on the specific intervention. Furthermore, our results suggest that at least in the planning domain patients with impaired performance benefit particularly from a specific intervention.


Harm Reduction Journal | 2014

Ethnic- and gender-specific differences in the prevalence of HIV among patients in opioid maintenance treatment—a case register analysis

Michael Liebrenz; Rudolf Stohler; Carlos Nordt

BackgroundWe have sought to identify ethnic- and gender-specific differences in HIV prevalence among heroin users receiving opioid maintenance treatment in the canton of Zurich, Switzerland.MethodsWe used a generalized linear model (GEE) to analyze data from the anonymized case register for all opioid maintenance treatments in the canton of Zurich. Patients who received either methadone or buprenorphine between 1991 and 2012 (n = 11,422) were evaluated for gender (male vs. female), ethnic background (Swiss vs. non-Swiss), and lifetime method of drug use (ever injector vs. non-injector). We addressed missing data by multiple imputation.ResultsThe overall prevalence of HIV among patients declined substantially from 33.7% in 1991 to 10.6% in 2012 in the complete dataset. In the imputed datasets, the respective prevalence dropped from 32.8% in 1991 to 9.7% in 2012. Non-injectors had a four to five times lower risk ratio (RR) compared to the reference group, ‘Swiss males who ever injected’. In addition, we found a significantly higher risk ratio of HIV prevalence among females who had ever injected; this was true both for the complete dataset and the imputed dataset (Swiss RR 1.18 CI 95% 1.04–1.34, non-Swiss RR 1.58 CI 95% 1.18–2.12).ConclusionIn this population, gender, ethnic background, and lifetime method of drug use influenced the risk of being HIV positive. Different access to treatment and different characteristics of risk exposure among certain subgroups might explain these findings. In particular, the higher risk for women who inject drugs—especially for those with an immigrant background—warrants additional research. Further exploration should identify what factors deter women from using available HIV-prevention measures and whether and how these measures can be better adapted to high-risk groups.


Journal of Medical Case Reports | 2012

High dose methylphenidate treatment in adult Attention Deficit Hyperactivity Disorder: a case report

Michael Liebrenz; Danielle Hof; Anna Buadze; Rudolf Stohler; Dominique Eich

IntroductionStimulant medication improves hyperactivity, inattention, and impulsivity in both pediatric and adult populations with Attention Deficit Hyperactivity Disorder (ADHD). However, data regarding the optimal dosage in adults is still limited.Case presentationWe report the case of a 38-year-old Caucasian patient who was diagnosed with Attention Deficit Hyperactivity Disorder when he was nine years old. He then received up to 10 mg methylphenidate (Ritalin®) and 20 mg sustained-release methylphenidate (Ritalin SR®) daily. When he was 13, his medication was changed to desipramine (Norpramin®), and both Ritalin® and Ritalin SR® were discontinued; and at age 18, when he developed obsessive-compulsive symptoms, his medication was changed to clomipramine (Anafranil®) 75 mg daily. Still suffering from inattention and hyperactivity, the patient began college when he was 19, but did not receive stimulant medication until three years later, when Ritalin® 60 mg daily was re-established. During the 14 months that followed, he began to use Ritalin® excessively, both orally and rectally, in dosages from 4800-6000 mg daily. Four years ago, he was referred to our outpatient service, where his Attention Deficit Hyperactivity Disorder was re-evaluated. At that point, the patient’s daily Ritalin® dosage was reduced to 200 mg daily orally, but he still experienced pronounced symptoms of, Attention Deficit Hyperactivity Disorder so this dosage was raised again. The patient’s plasma levels consistently remained between 60–187 nmol/l—within the recommended range—and signs of his obsessive-compulsive symptoms diminished with fluoxetine 40 mg daily. Finally, on a dosage of 378 mg extended-release methylphenidate (Concerta®), his symptoms of Attention Deficit Hyperactivity Disorder have improved dramatically and no further use of methylphenidate has been recorded during the 24 months preceding this report.ConclusionsSymptoms of Attention Deficit Hyperactivity Disorder (ADHD) in this adult patient, who also manifested a co-occurring obsessive compulsive disorder, dramatically improved only after application of a higher-than-normal dose of methylphenidate. We therefore suggest that clinicians consider these findings in relation to their adherence to current therapeutic guidelines.


PLOS ONE | 2017

Skills and compensation strategies in adult ADHD - A qualitative study.

Carlos Canela; Anna Buadze; Anish Dube; Dominique Eich; Michael Liebrenz

Objective The primary objectives of this study were to investigate how adult patients with ADHD coped with their symptoms prior to diagnosis and treatment, what skills and compensation strategies they had developed and what their self-perceptions of these strategies were. Methods We used a qualitative approach to analyze interviews with 32 outpatients of a specialty care unit at a university hospital. Results Patients reported frequent use of diverse compensatory strategies with varying degrees of effectiveness. These were classified into five categories (organizational, motoric, attentional, social, psychopharmacological). In certain circumstances, ADHD symptoms were even perceived as useful. Conclusion Before diagnosis and treatment, patients with ADHD may develop a variety of skills to cope with their symptoms. Several of these skills are perceived as helpful. Knowledge of self-generated coping strategies may help better understand patients and their histories and thus facilitate patient cooperation. Moreover, knowing ways in which such patients cope with their symptoms may help elucidate reasons for late or under-diagnosing of the disorder.


Journal of Forensic Psychiatry & Psychology | 2018

The relationship between childhood traumatic events, social support, and mental health problems in prisoners

Sandy Krammer; Hedwig Eisenbarth; David Hügli; Michael Liebrenz; Philipp Kuwert

Abstract This study examined the prevalence of childhood traumatic events (CTE), social support levels as well as mental health problems (MHP), to test for differences between traumatized and non-traumatized individuals, and to investigate the relationship among the aforementioned parameters in a sample of 49 prisoners in Switzerland. This cross-sectional study used standardized self-report measurements. In line with expectations, prisoners reported a high rate of traumatic events. Furthermore, results indicated that those traumatized differed from those non-traumatized regarding the level of social support, interpersonal sensitivity, and depression. However, no relationship between CTE and social support as well as MHP was found. This points to specific therapeutic needs of those traumatized, and to the necessity of a trauma-informed correctional care. Moreover, these study results are a further step into more integrated models of criminal behavior.


Frontiers in Psychiatry | 2018

Predicting medical students' current attitudes toward psychiatry, interest in psychiatry, and estimated likelihood of working in psychiatry: A cross-sectional study in four European countries

Ingeborg Warnke; Alex Gamma; Maria Buadze; Roman Schleifer; Carlos Canela; Bernd Strebel; Tamás Tényi; Wulf Rössler; Nicolas Rüsch; Michael Liebrenz

Psychiatry as a medical discipline is becoming increasingly important due to the high and increasing worldwide burden associated with mental disorders. Surprisingly, however, there is a lack of young academics choosing psychiatry as a career. Previous evidence on medical students’ perspectives is abundant but has methodological shortcomings. Therefore, by attempting to avoid previous shortcomings, we aimed to contribute to a better understanding of the predictors of the following three outcome variables: current medical students’ attitudes toward psychiatry, interest in psychiatry, and estimated likelihood of working in psychiatry. The sample consisted of N = 1,356 medical students at 45 medical schools in Germany and Austria as well as regions of Switzerland and Hungary with a German language curriculum. We used snowball sampling via Facebook with a link to an online questionnaire as recruitment procedure. Snowball sampling is based on referrals made among people. This questionnaire included a German version of the Attitudes Toward Psychiatry Scale (ATP-30-G) and further variables related to outcomes and potential predictors in terms of sociodemography (e.g., gender) or medical training (e.g., curriculum-related experience with psychiatry). Data were analyzed by linear mixed models and further regression models. On average, students had a positive attitude to and high general interest in, but low professional preference for, psychiatry. A neutral attitude to psychiatry was partly related to the discipline itself, psychiatrists, or psychiatric patients. Female gender and previous experience with psychiatry, particularly curriculum-related and personal experience, were important predictors of all outcomes. Students in the first years of medical training were more interested in pursuing psychiatry as a career. Furthermore, the country of the medical school was related to the outcomes. However, statistical models explained only a small proportion of variance. The findings indicate that particularly curriculum-related experience is important for determining attitudes toward psychiatry, interest in the subject and self-predicted professional career choice. We therefore encourage the provision of opportunities for clinical experience by psychiatrists. However, further predictor variables need to be considered in future studies.

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Anish Dube

University of Pennsylvania

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