Studies comparing antidepressants with benzodiazepines in the treatment of GAD showed that although benzodiazepines work quickly, the antidepressants lower anxiety more effectively in the long term.[11] Antidepressants that have been approved by the United States Food and Drug Administration (FDA) for the treatment of GAD are extended-release venlafaxine,[12] duloxetine,[13] escitalopram,[14] and paroxetine.[15] Although not FDA approved, citalopram has also been found to be effective for the treatment of GAD.[16] Whereas benzodiazepines have been shown effective for shortterm anxiety, they may worsen depression, a common comorbidity of GAD, and cause other cognitive adverse effects such as sedation and anterograde amnesia. Individuals with a history of substance abuse or dependence should not use benzodiazepines, but patients with no such history rarely abuse these agents and can use them safely.[17] Buspirone and pregabalin also have proven efficacy for GAD.[18–21]
Table 1. Summary of Clinical Trials of Adjunctive Use of Atypical Antipsychotics for Treatment-Resistant Generalized Anxiety Disordera
Agent | Study Design | No. of Patients | Study Duration (wks) | Mean Daily Dose (mg) | Change in Assessment Score | Mean Weight Gain (lbs)b |
Aripiprazole[30] | Open label | 17 | 4.9 | 16.9 | CGI-S: −1.6 | NR |
Aripiprazole[31] | Open label | 10 | 9 | NR | HAM-A: −20.6 | 7.1 |
Aripiprazole[32] | Open label | 9 | 6 | 13.9 | HAM-A: −12 CGI-I: 8 of 9 patients rated as much improved or very much improved | NR |
Aripiprazole[33] | Open label | 23 | 8 | 10.5 | HAM-A: −6.7 CGI-S: −1 | 2.5 |
Olanzapine[34] | Randomized, controlled | 21 | 6 | 8.7 | HAM-A: olanzapine −7 vs placebo −3.9 (p=0.4) CGI-S: 67% of patients rated as not at all ill or borderline ill | 11 |
Quetiapine[35] | Randomized, controlled | 58 | 8 | 182 | HAM-A: quetiapine −12.5 vs placebo −5.9 (p=0.002) | 5.2 |
Quetiapine[36] | Randomized, controlled | 22 | 8 | 120 | HAM-A: quetiapine −2.6 vs placebo −0.3 (p=0.98) | 2.7 |
Quetiapine[37] | Open label | 40 | 12 | 386 | HAM-A: −20.6 | 1.1 |
Risperidone[38] | Open label | 16 | 8 | 1.12 | HAM-A: −6.75 CGI-S: −1.53 | 3.9 |
Risperidone[39] | Randomized, controlled | 40 | 5 | 1.1 | HAM-A: risperidone −9.8 vs placebo −6.2 (p=0.034) | 2.3 |
Risperidone[40] | Randomized, controlled | 390 | 4 | 0.86 | HAM-A: risperidone −9.26 vs placebo −9.12 (p=0.858) PaRTS-A: risperidone −8.54 vs placebo −7.61 (p=0.265) | 2.65 |
Ziprasidone[41] | Open label | 13 | 7 | 40 | HAM-A: −11.2 | 0.2 |
HAM-A = Hamilton Rating Scale for Anxiety (lower scores indicate less severe symptoms of anxiety); CGI-S = Clinical Global Impressions-Severity (lower scores indicate less severe illness); CGI-I = Clinical Global Impression–Improvement; NR = not reported; PaRTS-A = Patient-Rated TroublingSymptoms for Anxiety.
aAll atypical antipsychotic treatment was added to current antidepressant therapy.
bIn patients who received the atypical antipsychotic.
Adjunctive Use of Atypical Antipsychotics for Treatment-resistant Generalized Anxiety Disorder