Potentiating
effect of gabapentin in treatment-resistant
depression
The
aim of this study was to investigate the ability
of gabapentin to potentiate antidepressants in
treatment-resistant depression.
Forty-eight outpatients suffering from unipolar
recurrent major depression who had been treated
unsuccessfully with several classes of
antidepressants such as citalopram (n = 26),
venlafaxine (n = 8), imipramine (n = 12) and
phenelzine (n = 2) were recruited. Their mean
age was 47.65 ± 12.35 and mean number of
prior episodes was 3.2 ± 1.7. The patients
were treated with open-label gabapentin
(300-1,600 mg/day) in combination with these
antidepressants at least for 8 weeks in a
prospective case-series design. Clinical Global
Impression (CGI) scale was used to determine
efficacy with either CGI ratings of much or very
much improved, or no symptoms of major
depression.
Thirty-four (71%) patients were assessed as
responders to gabapentin (mean daily dose of 850
mg) in combination with antidepressants after an
8-week treatment. No differences existed at the
baseline level of severity of illness, sex,
duration of illness and number of prior episodes
between responders and non-responders. No
relationship between the different classes of
antidepressants and the potentiation was
observed. There was, however, a relationship
between the intensity of side effects of a
combination the clinical response.
These results suggest that gabapentin may
represent an attractive alternative as an
augmentation agent in depression resistant to a
wide range of antidepressant treatments,
including selective serotonin reuptake
inhibitors, serotonin and noradrenaline reuptake
inhibitors, tricyclics and monoamine oxidase
inhibitors. Controlled studies are required
to support these findings. Eur
Neuropsychopharmacol 12 (Suppl 3): S225,
2002