Olanzapine or lamotrigine addition to lithium in remitted bipolar disorder patients with anxiety disorder comorbidity: a randomized, single-blind, pilot study.
OBJECTIVE
The aim of the present randomized, single-blind, pilot study was to assess the efficacy of the addition of a second mood stabilizer, either olanzapine or lamotrigine, to lithium in patients with remitted bipolar disorder and comorbid anxiety disorder.


METHODS
Adult DSM-IV bipolar disorder patients with a current anxiety disorder and a Hamilton Rating Scale for Anxiety (HAM-A) score of 12 or higher, in remission from an affective episode for at least 2 months while on lithium maintenance treatment, were randomly assigned to receive 12 weeks of single-blind olanzapine 5 to 10 mg/day (N = 24) or lamotrigine 50 to 200 mg/day (N = 23) addition to lithium. The primary outcome measure was the HAM-A; secondary outcome measures were the Clinical Global Impressions-Severity of Illness scale and the Global Assessment of Functioning (GAF) scale. Data were collected from July 2005 to February 2007.


RESULTS
Twenty-two patients in the olanzapine and 18 in the lamotrigine group completed the trial. Mean +/- SD final doses of olanzapine and lamotrigine were, respectively, 7.7 +/- 4.2 mg/day and 96.7 +/- 46.7 mg/day in the intent-to-treat sample (N = 47). Both olanzapine and lamotrigine were effective in reducing HAM-A scores from baseline to endpoint (paired t test for completers: t = 11.361, df = 21, p < .001 for olanzapine and t = 6.301, df = 17, p < .001 for lamotrigine). Both drugs were also effective on the secondary outcome measures. Olanzapine was more effective than lamotrigine at weeks 6 and 12 with a last-observation-carried-forward analysis on all 3 outcome measures, while such differences disappeared on the HAM-A and GAF at week 12 with the visit-wise analysis.


CONCLUSIONS
The addition of a second mood stabilizer (olanzapine or lamotrigine) to lithium is effective in reducing anxiety symptoms in bipolar disorder patients with a co-occurring anxiety disorder.
Maina
Giuseppe
G
Department of Neurosciences, Mood and Anxiety Disorders Unit, University of Turin, Turin, Italy. giuseppemaina@hotmail.com
Albert
Umberto
U
Rosso
Gianluca
G
Bogetto
Filippo
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D001569:Benzodiazepines / Q000008:administration & dosage / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D015897:Comorbidity; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D000077213:Lamotrigine; D016651:Lithium Carbonate / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D010865:Pilot Projects; D016037:Single-Blind Method; D014227:Triazines / Q000008:administration & dosage / Q000627:therapeutic use*
D014150:Antipsychotic Agents; D014227:Triazines; D001569:Benzodiazepines; D016651:Lithium Carbonate; D000077152:Olanzapine; D000077213:Lamotrigine