Open-label tiagabine monotherapy for major depressive disorder with anxiety.
OBJECTIVE
Gamma-aminobutyric acid (GABA) plays a key role in the pathophysiology and treatment of depression and anxiety. Tiagabine, a selective GABA reuptake inhibitor (SGRI) that enhances normal GABA tone, was evaluated for its efficacy and safety in the treatment of depression comorbid with significant anxiety.


METHODS
In this 8-week, single-center, open-label study, adults with DSM-IV-diagnosed major depressive disorder and significant anxiety (i.e., "anxious depression") received tiagabine monotherapy, initiated at 4 mg/day and titrated for optimum response as tolerated to a maximum dose of 20 mg/day. Symptoms, function, and adverse events were assessed at regular intervals. Patients were entered from April 2002 to February 2003.


RESULTS
Nineteen patients entered the study and 15 met criteria for intent-to-treat analyses. Of those, 6 (40%) discontinued treatment and 9 (60%) completed the 8-week protocol. Tiagabine significantly improved depression, as shown by a reduction in mean +/- SD Hamilton Rating Scale for Depression scores from baseline (31.9 +/- 6.1) to endpoint (17.0 +/- 12.4; p = .002). Categorical response rate was 47% (N = 7). Tiagabine also significantly improved anxiety (Hamilton Rating Scale for Anxiety baseline score of 22.7 +/- 4.9 vs. endpoint score of 12.5 +/- 8.8; p = .002). The mean +/- SD final daily dose was 12.8 +/- 5.8 mg. The most commonly reported adverse events were dizziness, headache, and gastrointestinal upset/nausea.


CONCLUSIONS
These results suggest the potential of the SGRI tiagabine in the treatment of depression with anxiety. Large, placebo-controlled trials are needed.
Carpenter
Linda L
LL
Mood Disorders Research Program, Butler Hospital, Brown Medical School, 345 Blackstone Boulevard, Providence, R.I. 02906, USA. Linda_Carpenter_MD@brown.edu
Schecter
Jordan M
JM
Tyrka
Audrey R
AR
Mello
Andrea F
AF
Mello
Marcelo F
MF
Haggarty
Ryan
R
Price
Lawrence H
LH
D000328:Adult; D000553:Ambulatory Care; D001008:Anxiety Disorders / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014179:Neurotransmitter Uptake Inhibitors / Q000627:therapeutic use*; D009557:Nipecotic Acids / Q000627:therapeutic use*; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D000078308:Tiagabine; D016896:Treatment Outcome; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D014179:Neurotransmitter Uptake Inhibitors; D009557:Nipecotic Acids; D005680:gamma-Aminobutyric Acid; D000078308:Tiagabine