title: Variation in response to short-term antidepressant treatment between patients with continuous and non-continuous cycling bipolar disorders.
abstract: OBJECTIVE
  The study aimed to compare effectiveness and safety of short-term antidepressant treatment between patients with continuous (CCC) and non-continuous (N-CCC) cycling bipolar disorders.
  
  
  METHODS
  The study sample included 101 patients with bipolar disorder, 22 (21.8%) CCC and 79 (78.2%) N-CCC. Response was defined as a HDRS21 total score <7 at 12 weeks of treatment and remission as a ≥50% reduction of baseline HDRS21 total score sustained for 8 weeks.
  
  
  RESULTS
  Compared with N-CCC patients, CCC patients achieved a significantly lower percentage of response (respectively 50% vs. 82.3%, χ²=9.6, p=0.002) and remission (respectively 40.9% vs. 69.6%, χ²=6.11, p=0.013). Adjusted logistic regression analysis indicated that CCC patients were 4.3 times more likely to be non-responders and 3.3 times more likely to be non-remitters than N-CCC patients.
  AD safety, 1 (5.0%) CCC patient committed a suicide attempt and AD-emerging switch was observed in 2 patients with N-CCC (2.5%) and in 1 with CCC (4.5%).
  
  
  CONCLUSIONS
  The observational nature of the study, retrospective assessment of course, and unblinded outcomes assessment.
  
  
  CONCLUSIONS
  Our findings indicate that the presence or absence of a free interval identifies two different forms of bipolar disorders with different response not only to prophylactic treatment, as previously reported, but also to short-term ADs. We submit that clinicians should take into consideration their patients׳ pattern of cycling when prescribing short-term AD treatment. Moreover, subtypes of bipolar disorders might be used as moderators of treatment response in studies assessing the efficacy or the effectiveness of antidepressant treatment.
authors.affiliation: Istituto di Psicopatologia, Roma, Italy. Electronic address: tundo@istitutodipsicopatologia.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Tundo
authors.affiliation: Department of Psychiatry, University Hospital Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Calabrese
authors.affiliation: Istituto di Psicopatologia, Roma, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Proietti
authors.affiliation: Istituto di Psicopatologia, Roma, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: de Fillippis
mesh_terms: D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000523:psychology*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013406:Suicide, Attempted / Q000517:prevention & control* / Q000706:statistics & numerical data*; D013997:Time Factors
chemical_list: D000928:Antidepressive Agents
keywords: Antidepressants; Bipolar depression; Bipolar disorders; Course; Outcome; Short-term treatment