Gabriele S. Leverich

OBJECTIVE: Bipolar disorder often co-occurs with other axis I disorders, but little is known about the relationships between the clinical features of bipolar illness and these comorbid conditions. Therefore, the authors assessed comorbid lifetime and current axis I disorders in 288 patients with bipolar disorder and the relationships of these comorbid disorders to selected demographic and historical illness variables. METHOD: They evaluated 288 outpatients with bipolar I or II disorder, using structured diagnostic interviews and clinician-administered and self-rated questionnaires to determine the diagnosis of bipolar disorder, comorbid axis I disorder diagnoses, and demographic and historical illness characteristics. RESULTS: One hundred eighty-seven (65%) of the patients with bipolar disorder also met DSM-IV criteria for at least one comorbid lifetime axis I disorder. More patients had comorbid anxiety disorders (N=78, 42%) and substance use disorders (N=78, 42%) than had eating disorders (N=9, 5%). There were no differences in comorbidity between patients with bipolar I and bipolar II disorder. Both lifetime axis I comorbidity and current axis I comorbidity were associated with earlier age at onset of affective symptoms and syndromal bipolar disorder. Current axis I comorbidity was associated with a history of development of both cycle acceleration and more severe episodes over time. CONCLUSIONS: Patients with bipolar disorder often have comorbid anxiety, substance use, and, to a lesser extent, eating disorders. Moreover, axis I comorbidity, especially current comorbidity, may be associated with an earlier age at onset and worsening course of bipolar illness. Further research into the prognostic and treatment response implications of axis I comorbidity in bipolar disorder is important and is in progress.

OBJECTIVE: The longitudinal course of 51 patients with treatment-refractory bipolar disorder was examined to assess possible effects of heterocyclic antidepressants on occurrence of manic episodes and cycle acceleration. METHOD: Using criteria established from life charts, investigators rated the patients' episodes of mania or cycle acceleration as likely or unlikely to have been induced by antidepressant therapy. Discriminant function analyses were performed to assess predictors of vulnerability to antidepressant-induced mania or cycle acceleration. Further, the likelihood of future antidepressant-induced episodes in persons who had had one such episode was assessed. RESULTS: Thirty-five percent of the patients had a manic episode rated as likely to have been antidepressant-induced. No variable was a predictor of vulnerability to antidepressant-induced mania. Cycle acceleration was likely to be associated with antidepressant treatment in 26% of the patients assessed. Younger age at first treatment was a predictor of vulnerability to antidepressant-induced cycle acceleration. Forty-six percent of patients with antidepressant-induced mania, but only 14% of those without, also showed antidepressant-induced cycle acceleration at some point in their illness. CONCLUSIONS: Mania is likely to be antidepressant-induced and not attributable to the expected course of illness in one-third of treatment-refractory bipolar patients, and rapid cycling is induced in one-fourth. Antidepressant-induced mania may be a marker for increased vulnerability to antidepressant-induced cycle acceleration. Antidepressant-induced cycle acceleration (but not antidepressant-induced mania) is associated with younger age at first treatment and may be more likely to occur in women and in bipolar II patients.

There is a pressing need for additional treatment options for refractory mood disorders. This controlled comparative study evaluated the efficacy of lamotrigine (LTG) and gabapentin (GBP) monotherapy versus placebo (PLC). Thirty-one patients with refractory bipolar and unipolar mood disorders participated in a double-blind, randomized, crossover series of three 6-week monotherapy evaluations including LTG, GBP, and PLC. There was a standardized blinded titration to assess clinical efficacy or to determine the maximum tolerated daily dose (LTG 500 mg or GBP 4,800 mg). The primary outcome measure was the Clinical Global Impressions Scale (CGI) for Bipolar Illness as supplemented by other standard rating instruments. The mean doses at week 6 were 274 +/- 128 mg for LTG and 3,987 +/- 856 mg for GBP. Response rates (CGI ratings of much or very much improved) were the following: LTG, 52% (16/31); GBP, 26% (8/31); and PLC, 23% (7/31) (Cochran's Q = 6.952, df = 2, N = 31, p = 0.031). Post hoc Q differences (df = 1, N = 31) were the following: LTG versus GBP (Qdiff = 5.33, p = 0.011); LTG versus PLC (Qdiff = 4.76, p = 0.022); and GBP versus PLC (Qdiff = 0.08, p = 0.70). With respect to anticonvulsant dose and gender, there was no difference between the responders and the nonresponders. The agents were generally well tolerated. This controlled investigation preliminarily suggests the efficacy of LTG in treatment-refractory affectively ill patients. Further definition of responsive subtypes and the role of these medications in the treatment of mood disorders requires additional study.