The effect of axis I psychiatric comorbidity on treatment response on outpatients with bipolar disorders: two year follow-up study in the naturalistic setting

  • Boseok Cha, Department of Psychiatry, Gyeongsang National University Hospital, Korea
  • Jeong Hyun Kim, Mood Disorders Clinic & Affective Neuroscience Laboratory, Department of Psychiatry, Seoul National University Bundang Hospital, Korea
  • Eunsoo Moon, Mood Disorders Clinic & Affective Neuroscience Laboratory, Department of Psychiatry, Seoul National University Bundang Hospital, Korea
  • Jung Eun Choi, Department of Psychiatry, Seoul Metropolitan Eunpyoung Hospital, Korea
  • Jae Seung Chang, Mood Disorders Clinic & Affective Neuroscience Laboratory, Department of Psychiatry, Seoul National University Bundang Hospital, Korea
  • Tae Hyon Ha, Mood Disorders Clinic & Affective Neuroscience Laboratory, Department of Psychiatry, Seoul National University Bundang Hospital, Korea
  • Kyooseob Ha, Mood Disorders Clinic & Affective Neuroscience Laboratory, Department of Psychiatry, Seoul National University Bundang Hospital, Korea

Objective: This study aims to investigate whether there is any difference in treatment response according to the presence of axis I psychiatric comorbidity in bipolar disorders outpatients.
Methods: The study sample included 195 outpatients with bipolar I disorder(n = 85) and bipolar II disorder(n = 110). All patients were symptomatic, based on the Montgomery Asberg Depression Rating Scale(MADRS) scores > 8 and Young Mania Rating Scale(YMRS) ≥ 5, and were managed by conventional treatment regimen by their clinicians. Subjects were interviewed to evaluate comorbidity using the structured clinical interview for DSM-IV(SCID). The assessment of mood symptoms was done with MADRS and YMRS at intake and 6, 12, 24-month. Symptomatic remission was defined as MADRS scores ≤ 7 and YMRS < 5. The remission rates were compared between the group with axis I comorbidity(C+) and the group without any axis I comorbidity(C-).
Results: The remission rate of the C(+) were 27.9%, 35.7%, 38.9% and those of C(-) were 45%, 46.7%, 62.2% at 6, 12, 24 months,respectively. The chi-square test for the proportion of remitted patients were χ2=3.434(p=0.064), χ2=0.933(p=0.365), χ2=2.645(p=0.104) at 6, 12, 24 months respectively. The remission rates did not differ between the two groups, although there was a tendency toward lower remission rates in the C(+).
Conclusions: The axis I psychiatric comorbidity was associated with a poorer treatment response in bipolar disorders outpatients. A more systematic treatment approach is needed to lessen the morbidity caused by psychiatric comorbidity in bipolar disorders patients.