An open trial of topiramate in the treatment of generalized social phobia.
BACKGROUND
Selective serotonin reuptake inhibitors (SSRIs) are the current gold standard in the pharmacologic treatment of generalized social phobia. SSRIs are only effective in approximately 50% of individuals with generalized social phobia and can be associated with significant side effects. Based on the successful use of the anticonvulsants gabapentin and pregabalin in treating generalized social phobia, we conducted an open trial examining the efficacy of the glutamatergic and GABAergic anticonvulsant topiramate in the treatment of generalized social phobia.


METHODS
Twenty-three adult outpatients with DSM-IV social phobia, generalized type, were entered into a 16-week open trial of topiramate, starting at 25 mg/day, and gradually titrated up to a maximum dose of 400 mg/day.


RESULTS
Twelve of 23 patients completed the trial. In the intent-to-treat (ITT) analysis, 11 (47.8%) of 23 were responders by a Clinical Global Impressions Improvement (CGI-I) scale rating of "much" or "very much" improved. The mean drop in the Liebowitz Social Anxiety Scale (LSAS) score for the ITT group was 29.4%. The change in LSAS score from baseline to endpoint was significant for the ITT group (F = 3.44, df = 4,110; p = .01). In the completers group, 9 (75.0%) of 12 were responders by CGI-I at 16 weeks, with a mean drop in LSAS score of 45.1%. The rate of remission in the ITT sample, using a definition of an LSAS score of </= 30, gave a remission rate of 26.1% (6/23).


CONCLUSIONS
This study suggests that topiramate may be effective in the treatment of generalized social phobia. These results also suggest the possibility that the neurotransmitters glutamate and GABA may be involved in the neurobiology of generalized social phobia.
Van Ameringen
Michael
M
Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada. vanamer@mcmaster.ca
Mancini
Catherine
C
Pipe
Beth
B
Oakman
Jonathan
J
Bennett
Mark
M
D000328:Adult; D017668:Age of Onset; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use*; D015897:Comorbidity; D004334:Drug Administration Schedule; D005260:Female; D005632:Fructose / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D006261:Headache / Q000139:chemically induced; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology; D008875:Middle Aged; D010292:Paresthesia / Q000139:chemically induced; D010698:Phobic Disorders / Q000188:drug therapy* / Q000453:epidemiology / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D000077236:Topiramate; D016896:Treatment Outcome; D015431:Weight Loss
D000927:Anticonvulsants; D000077236:Topiramate; D005632:Fructose