title: Lithium excessively enhances event related beta oscillations in patients with bipolar disorder.
abstract: BACKGROUND
  Previous resting-state electroencephalography studies have consistently shown that lithium enhances delta and theta oscillations in default mode networks. Cognitive task based networks differ from resting-state networks and this is the first study to investigate effects of lithium on evoked and event-related beta oscillatory responses of patients with bipolar disorder.
  
  
  METHODS
  The study included 16 euthymic patients with bipolar disorder on lithium monotherapy, 22 euthymic medication-free patients with bipolar disorder and 21 healthy participants. The maximum peak-to-peak amplitudes were measured for each subject's averaged beta responses (14-28 Hz) in the 0-300 ms time window. Auditory simple and oddball paradigm were presented to obtain evoked and event-related beta oscillatory responses.
  
  
  RESULTS
  There were significant differences in beta oscillatory responses between groups (p=0.010). Repeated measures ANOVA revealed location (p=0.007), laterality X group (p=0.043) and stimulus X location (p=0.013) type effects. Serum lithium levels were correlated with beta responses.
  
  
  CONCLUSIONS
  The lithium group had higher number of previous episodes, suggesting that patients of the lithium were more severe cases than patients of the medication-free group.
  
  
  CONCLUSIONS
  Lithium stimulates neuroplastic cascades and beta oscillations become prominent during neuroplastic changes. Excessively enhanced beta oscillatory responses in the lithium-treated patients may be indicative of excessive activation of the neuron groups of the certain cognitive networks and dysfunctional GABAergic modulation during cognitive activity.
authors.affiliation: Yıldırım Beyazıt University, Faculty of Medicine, Department of Psychiatry, Ankara, Turkey; Ankara Atatürk Training and Education Hospital, Department of Psychiatry, Ankara, Turkey.
authors.forename: Murat İlhan
authors.initials: Mİ
authors.lastname: Atagün
authors.affiliation: Istanbul Kultur University, Brain Dynamics, Cognition and Complex Systems Research Center, Ataköy Campus Bakırköy, 34156 Istanbul, Turkey.
authors.forename: Bahar
authors.initials: B
authors.lastname: Güntekin
authors.affiliation: Maltepe University, Faculty of Medicine, Department of Psychiatry, Istanbul, Turkey.
authors.forename: Devran
authors.initials: D
authors.lastname: Tan
authors.affiliation: Istanbul Kultur University, Brain Dynamics, Cognition and Complex Systems Research Center, Ataköy Campus Bakırköy, 34156 Istanbul, Turkey.
authors.forename: Emine Elif
authors.initials: EE
authors.lastname: Tülay
authors.affiliation: Istanbul Kultur University, Brain Dynamics, Cognition and Complex Systems Research Center, Ataköy Campus Bakırköy, 34156 Istanbul, Turkey. Electronic address: e.basar@iku.edu.tr.
authors.forename: Erol
authors.initials: E
authors.lastname: Başar
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001611:Beta Rhythm / Q000187:drug effects* / Q000502:physiology; D001714:Bipolar Disorder / Q000188:drug therapy / Q000503:physiopathology*; D016022:Case-Control Studies; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005260:Female; D006801:Humans; D008094:Lithium / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D008094:Lithium
keywords: Bipolar disorder; Brain oscillations; Euthymia; Event-related oscillations; Lithium