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A clinical evaluation of the DSM-5 criteria for Internet Gaming Disorder and a pilot study on their applicability to further Internet-related disorders
Authors: Kai W. Müller, Manfred E. Beutel, Michael Dreier and Klaus Wölfling

Background and aims

Internet Gaming Disorder (IGD) and other Internet-related disorders (IRDs) have become growing health concerns in our today’s lives. Based on defined diagnostic criteria, IGD has been recognized as a condition for further research in the DSM-5; however, other IRDs have been excluded. Since the release of the DSM-5, representativeness and appropriateness of the nine diagnostic criteria have been debated. Although some first evidence has been published to evaluate these criteria, our knowledge is still limited. Thus, the purpose of this study was to provide data on the clinical validity of the DSM-5 criteria for IGD and other types of IRD. We were also interested in examining the additional diagnostic validity of craving that is currently not being considered in the DSM-5.

Methods

Analyses on a sample of n = 166 treatment seekers for IRDs were performed. The clinician’s diagnosis was used as a main reference for determining the DSM criteria’s diagnostic performance. Secondary criteria (depression and anxiety) were defined as indicators for the construct validity.

Results

The overall diagnostic accuracy ranged between 76.6% for deceiving and 92% for loss of control and craving. Considerable differences occurred in the degree of sensitivity and specificity between the single criteria. No particular differences were found for the applicability of the criteria to other forms of IRDs.

Discussion and conclusions

Our results confirm the validity of the DSM criteria. However, the diagnostic utility of the criterion escaping aversive moods is critically discussed. Considering craving as an additional diagnostic indicator might be recommendable.

Open access
Bipolar spectrum disorders in a clinical sample of patients with Internet addiction: Hidden comorbidity or differential diagnosis?
Authors: Klaus Wölfling, Manfred E. Beutel, Michael Dreier and Kai W. Müller

Background and aims

Behavioral addictions and bipolar disorders have a certain probability of co-occurrence. While the presence of a manic episode has been defined as an exclusion criterion for gambling disorder, no such exclusion has been formulated for Internet addiction.

Methods

A clinical sample of 368 treatment seekers presenting with excessive to addictive Internet use was screened for bipolar spectrum disorders using the Mood Disorder Questionnaire. Psychopathology was assessed by the Symptom Checklist 90R and a clinical interview was administered to screen for comorbid disorders.

Results

Comorbid bipolar disorders were more frequent in patients meeting criteria for Internet addiction (30.9%) than among the excessive users (5.6%). This subgroup showed heightened psychopathological symptoms, including substance use disorders, affective disorders and personality disorders. Further differences were found regarding frequency of Internet use regarding social networking sites and online-pornography.

Discussion

Patients with Internet addiction have a heightened probability for meeting criteria of bipolar disorders. It is not possible to draw conclusions regarding the direction of this association but it is recommended to implement screening for bipolar disorders in patients presenting with Internet addiction.

Conclusion

Similar to gambling disorder, it might prove necessary to subsume bipolar disorders as an exclusion criterion for the future criteria of Internet addiction.

Open access
Prevalence, risk factors, and psychosocial adjustment of problematic gambling in adolescents: Results from two representative German samples
Authors: Sebastián Giralt, Kai W. Müller, Manfred E. Beutel, Michael Dreier, Eva Duven and Klaus Wölfling

Background and aims

Gambling disorder is a significant public health concern. Especially, male minors have been shown to gamble in a problematic way, despite legal prohibitions.

Methods

We examined representative samples of students aged from 12 to 18 years (N = 9,309) in two German federal states to provide prevalence data and clinical description of risk factors for problematic gambling.

Results

We found that about 40% of the adolescents reported engaging in gambling activities within the past 12 months and found prevalence rates of 1.7% and 2.2% for problematic gambling. Especially, use of online gambling and slot machines was found to be related to problematic gambling. Male adolescents with a migration background were of higher risk for problematic gambling and psychopathological symptoms were significantly elevated among that group.

Discussion

The results indicate that participation in gambling activities is common among underaged adolescents and that prevalence of problematic gambling exceeds rates of adults. Similarly, problematic gambling is associated with increased psychopathological strain.

Conclusion

Given that a high proportion of adult gamblers report having started gambling in adolescents, our data emphasize the need for prevention and early intervention strategies for problematic gambling.

Open access
Accurate detection of Helicobacter pylori antigen in human stool specimens by two novel immunoassays
Authors: Ralf Ignatius, Christiane Berg, Chris Weiland, Angela Darmer, Thilo Wenzel, Marion Lorenz, Jörg Fuhrmann and Michael Müller

Stool antigen tests are recommended for the diagnosis of Helicobacter pylori infection. Here, we compared two novel assays, i.e., one enzyme immunoassay (EIA) and one immunochromatography assay (ICA), with a chemiluminescence immunoassay (CLIA) that had previously been compared with rapid urease test, histology, and urea breath test. Two hundred sixty-six frozen stool samples with defined CLIA results (42 positives, 219 negatives, and 5 samples with borderline results) collected between January and May 2018 were thawed and immediately tested by EIA, ICA, and CLIA.

In 248 samples with repeatedly positive/negative CLIA results, EIA and ICA were positive for 40 and 37 of 41 CLIA-positive samples and yielded negative results for 206 and 201 of 207 CLIA-negative samples, respectively. There was a high positive percent agreement (EIA, 97.6%; 95% confidence interval (95% CI), 86.3–100%; ICA, 90.2%; 95% CI, 76.9–96.7%), as well as a negative percent agreement between the assays (EIA, 99.5%; 95% CI, 97.0–100%; ICA, 97.1%; 95% CI, 93.7–98.8%). This was further supported by kappa values indicating very good agreement (CLIA vs. EIA, 0.971; CLIA vs. ICA, 0.857). In conclusion, both EIA and ICA comprise valuable assays for the detection of H. pylori antigen in stool samples.

Open access
Engineering Polymer Microparticles by Droplet Microfluidics
Authors: Christophe A. Serra, Ikram U. Khan, ZhenQi Chang, Michel Bouquey, René Muller, Isabelle Kraus, Marc Schmutz, Thierry Vandamme, Nicolas Anton, Christian Ohm, Rudolf Zentel, Andrea Knauer and Michael Köhler

Abstract

Capillary-based flow-focusing and co-flow microsystems were developed to produce sphere-like polymer microparticles of adjustable sizes in the range of 50 to 600 μm with a narrow size distribution (CV < 5%) and different morphologies (core-shell, janus, and capsules). Rod-like particles whose length was conveniently adjusted between 400 μm and few millimeters were also produced using the same microsystems. Influence of operating conditions (flow rate of the different fluid, microsystem characteristic dimensions, and design) as well as material parameters (viscosity of the different fluids and surface tension) was investigated. Empirical relationships were thus derived from experimental data to predict the microparticle's overall size, shell thickness, or rods length. Besides morphology, microparticles with various compositions were synthesized and their potential applications highlighted: drug-loaded microparticles for new drug delivery strategies, composed inorganic-organic multiscale microparticles for sensorics, and liquid crystalline elastomer microparticles showing an anisotropic reversible shape change upon temperature for thermal actuators or artificial muscles.

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Clostridioides difficile in outpatients: application of a diagnostic algorithm recommended by the European Society of Clinical Microbiology and Infectious Diseases
Authors: Ralf Ignatius, Robert Neuber, Heike Kietzmann, Christiane Berg, Thilo Wenzel, Jörg Fuhrmann and Michael Müller

This study aimed at evaluating in outpatients an algorithm for the laboratory diagnosis of Clostridioides (Clostridium) difficile infection (CDI), i.e., enzyme immunoassays (EIAs) detecting bacterial glutamate dehydrogenase (GDH) and toxin A/B, followed by polymerase chain reaction (PCR) analyses of samples with discordant EIA results.

In total, 9802 examinations of stool samples by GDH and toxin EIAs performed in 7263 outpatients and 488 inpatients were analyzed retrospectively. Samples with discordant EIA results had been tested by a commercially available PCR assay detecting genes of the C. difficile-specific triose phosphate isomerase (tpi) and toxin B (tcdB).

Concordant EIA results (686 C. difficile-positive, 8121 negative) were observed for 8807 (89.8%; 95% CI, 89.2–90.4%) samples. Of 958 samples with discordant EIA results, 895 were analyzed using PCR and 580 of 854 GDH-positive/borderline, toxin-negative samples (67.9%; 95% CI, 64.7–71.0%) were positive for tpi and tcdB, while 274 samples (32.1%; 95% CI, 29.0–35.3%) were tcdB-negative. In contrast, 35 of 41 GDH-negative, toxin-positive/borderline samples (85.4%; 95% CI, 71.2–93.5%) were tcdB-negative. Still, 6 samples (14.6%; 95% CI, 6.5–28.8%) yielded positive PCR results for both genes.

In conclusion, around 90% of the samples were analyzed appropriately by only applying EIAs. Approximately one third of the PCR-analyzed samples were tcdB-negative; thus, patients most likely did not require CDI treatment.

Open access