@article{KopfGloecknerAlthenetal.2023,
  author    = {Kopf, Juliane and Gl{\"o}ckner, Stefan and Althen, Heike and Cevada, Thais and Schecklmann, Martin and Dresler, Thomas and Kittel-Schneider, Sarah and Reif, Andreas},
  title     = {Neural responses to a working memory task in acute depressed and remitted phases in bipolar patients},
  series = {Brain Sciences},
  volume    = {13},
  journal   = {Brain Sciences},
  number    = {5},
  issn      = {2076-3425},
  doi       = {10.3390/brainsci13050744},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313509},
  year      = {2023},
  abstract  = {(1) Cognitive impairments such as working memory (WM) deficits are amongst the most common dysfunctions characterizing bipolar disorder (BD) patients, severely contributing to functional impairment. We aimed to investigate WM performance and associated brain activation during the acute phase of BD and to observe changes in the same patients during remission. (2) Frontal brain activation was recorded using functional near-infrared spectroscopy (fNIRS) during n-back task conditions (one-back, two-back and three-back) in BD patients in their acute depressive (n = 32) and remitted (n = 15) phases as well as in healthy controls (n = 30). (3) Comparison of BD patients during their acute phase with controls showed a trend (p = 0.08) towards lower dorsolateral prefrontal cortex (dlPFC) activation. In the remitted phase, BD patients showed lower dlPFC and ventrolateral prefrontal cortex (vlPFC) activation (p = 0.02) compared to controls. No difference in dlPFC and vlPFC activation between BD patients' phases was found. (4) Our results showed decreased working memory performance in BD patients during the working memory task in the acute phase of disease. Working memory performance improved in the remitted phase of the disease but was still particularly attenuated for the more demanding conditions.},
  language  = {en}
}
@article{VolkertZierhutSchieleetal.2014,
  author    = {Volkert, Julia and Zierhut, Kathrin C. and Schiele, Miriam A. and Wenzel, Martina and Kopf, Juliane and Kittel-Schneider, Sarah and Reif, Andreas},
  title     = {Predominant polarity in bipolar disorder and validation of the polarity index in a German sample},
  doi       = {10.1186/s12888-014-0322-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111042},
  year      = {2014},
  abstract  = {Background: A large number of patients with bipolar disorder (BD) can be characterized by predominant polarity (PP), which has important implications for relapse prevention. Recently, Popovic et al. (EUR NEUROPSYCHOPHARM 22(5): 339-346, 2012) proposed the Polarity Index (PI) as a helpful tool in the maintenance treatment of BD. As a numeric expression, it reflects the efficacy of drugs used in treatment of BD. In the present retrospective study, we aimed to validate this Index in a large and well characterized German bipolar sample. Methods: We investigated 336 bipolar patients (BP) according to their PP and calculated the PI for each patient in order to prove if maintenance treatment differs according to their PP. Furthermore, we analysed whether PP is associated with demographic and clinical characteristics of BP. Results: In our sample, 63.9\% of patients fulfilled criteria of PP: 169 patients were classified as depressive predominant polarity (DPP), 46 patients as manic predominant polarity (MPP). The two groups differed significantly in their drug regime: Patients with DPP were more often medicated with lamotrigine and antidepressants, patients with MPP were more often treated with lithium, valproate, carbamazepine and first generation antipsychotics. However, patients with DPP and MPP did not differ significantly with respect to the PI, although they received evidence-based and guideline-driven treatment. Conclusion: The reason for this negative finding might well be that for several drugs, which were used frequently, no PI value is available. Nevertheless we suggest PP as an important concept in the planning of BD maintenance treatment.},
  language  = {en}
}
@article{KopfDreslerReichertsetal.2013,
  author    = {Kopf, Juliane and Dresler, Thomas and Reicherts, Philipp and Herrmann, Martin J. and Reif, Andreas},
  title     = {The Effect of Emotional Content on Brain Activation and the Late Positive Potential in a Word n-back Task},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0075598},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96687},
  year      = {2013},
  abstract  = {Introduction There is mounting evidence for the influence of emotional content on working memory performance. This is particularly important in light of the emotion processing that needs to take place when emotional content interferes with executive functions. In this study, we used emotional words of different valence but with similar arousal levels in an n-back task. Methods We examined the effects on activation in the prefrontal cortex by means of functional near-infrared spectroscopy (fNIRS) and on the late positive potential (LPP). FNIRS and LPP data were examined in 30 healthy subjects. Results Behavioral results show an influence of valence on the error rate depending on the difficulty of the task: more errors were made when the valence was negative and the task difficult. Brain activation was dependent both on the difficulty of the task and on the valence: negative valence of a word diminished the increase in activation, whereas positive valence did not influence the increase in activation, while difficulty levels increased. The LPP also differentiated between the different valences, and in addition was influenced by the task difficulty, the more difficult the task, the less differentiation could be observed. Conclusions Summarized, this study shows the influence of valence on a verbal working memory task. When a word contained a negative valence, the emotional content seemed to take precedence in contrast to words containing a positive valence. Working memory and emotion processing sites seemed to overlap and compete for resources even when words are carriers of the emotional content.},
  language  = {en}
}
@article{GalimbertiDell'OssoFenoglioetal.2012,
  author    = {Galimberti, Daniela and Dell'Osso, Bernardo and Fenoglio, Chiara and Villa, Chiara and Cortini, Francesca and Serpente, Maria and Kittel-Schneider, Sarah and Weigl, Johannes and Neuner, Maria and Volkert, Juliane and Leonhard, C. and Olmes, David G. and Kopf, Juliane and Cantoni, Claudia and Ridolfi, Elisa and Palazzo, Carlotta and Ghezzi, Laura and Bresolin, Nereo and Altamura, A.C. and Scarpini, Elio and Reif, Andreas},
  title     = {Progranulin Gene Variability and Plasma Levels in Bipolar Disorder and Schizophrenia},
  series = {PLoS One},
  volume    = {7},
  journal   = {PLoS One},
  number    = {4},
  doi       = {10.1371/journal.pone.0032164},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131910},
  pages     = {e32164},
  year      = {2012},
  abstract  = {Basing on the assumption that frontotemporal lobar degeneration (FTLD), schizophrenia and bipolar disorder (BPD) might share common aetiological mechanisms, we analyzed genetic variation in the FTLD risk gene progranulin (GRN) in a German population of patients with schizophrenia (n=271) or BPD (n=237) as compared with 574 age-, gender-and ethnicity-matched controls. Furthermore, we measured plasma progranulin levels in 26 German BPD patients as well as in 61 Italian BPD patients and 29 matched controls. A significantly decreased allelic frequency of the minor versus the wild-type allele was observed for rs2879096 (23.2 versus 34.2\%, P<0.001, OR: 0.63, 95\% CI: 0.49-0.80), rs4792938 (30.7 versus 39.7\%, P=0.005, OR: 0.70, 95\% CI: 0.55-0.89) and rs5848 (30.3 versus 36.8, P=0.007, OR: 0.71, 95\% CI: 0.56-0.91). Mean +/- SEM progranulin plasma levels were significantly decreased in BPD patients, either Germans or Italians, as compared with controls (89.69 +/- 3.97 and 116.14 +/- 5.80 ng/ml, respectively, versus 180.81 +/- 18.39 ng/ml P<0.001) and were not correlated with age. In conclusion, GRN variability decreases the risk to develop BPD and schizophrenia, and progranulin plasma levels are significantly lower in BPD patients than in controls. Nevertheless, a larger replication analysis would be needed to confirm these preliminary results.},
  language  = {en}
}