This is an open-label pilot study of adjunctive asenapine for the treatment of Posttraumatic Stress Disorder (PTSD) in veterans who have not fully remitted to an adequate trial of standard antidepressant treatment.

Consenting Veterans with the diagnosis of PTSD who have not fully remitted to an adequate trial of standard antidepressant treatment (sertraline, citalopram, escitalopram, fluoxetine, venlafaxine, or mirtazapine) are treated with the addition of open-label asenapine for 12-weeks.

Inclusion Criteria:

• Signed and dated informed consent and acceptable proof of identity.
• Male or female subjects ≥19 to 65 years of age of any race or ethnic origin.
• Not currently pregnant, breastfeeding or planning on becoming pregnant; use of contraception as follows:
• Males - those that are sexually active must use a double barrier method of contraception (condom with spermicide) from the first dose of asenapine until 12 weeks after last dose of asenapine
• Women of child-bearing potential - must have a negative urine pregnancy test and confirmed (by the investigator) use of a highly effective form of birth control for 3 months before enrollment and until 12 weeks after their last dose of asenapine.
• Women of non-child bearing potential - women who are either permanently sterilized (hysterectomy, bilateral oophorectomy and bilateral salpingectomy but excluding bilateral tubal occlusion) or who are postmenopausal.
• Diagnosis of PTSD (DSM-IV-TR criteria; confirmed by MINI and CAPS).
• Total CAPS score > 45.
• Currently taking an approved antidepressant at acceptable dose for 8 weeks or more with non-remission of symptoms.
• No substance use disorders of dependence (except for nicotine, caffeine) in previous 4 wks.
• No substance use disorders of abuse (except for nicotine and caffeine) in the previous 2 wks.
• Physical and laboratory panel (within past one year) are within normal limits or not clinically significant

Exclusion Criteria:

• Lifetime history of bipolar I, schizophrenia, schizoaffective or cognitive disorders (assessed by the MINI)
• Actively considering plans of suicide or homicide (assessed by clinical interview)
• Psychotic symptoms that in the investigator's opinion impair the subject's ability to give informed consent
• A contraindication to the use of asenapine or antidepessant
• Intolerable side effects or allergic reaction to asenapine or the current antidepressant
• Women planning to become pregnant or breastfeed during the study
• Clinically significant unstable or severe medical condition that would contraindicate study participation or expose them to an undue risk of a significant adverse event, including but not limited to: unstable or severe hepatic, renal, respiratory, cardiovascular, endocrine, neurologic, or hematologic disease; hypo- or hyperthyroidism, unless the condition has been stabilized; or a history of seizures (except for a single childhood febrile seizure, posttraumatic, or alcohol withdrawal). The following are exclusionary: platelets < 75,000/mm; hemoglobin <9g/dL; neutrophils, absolute < 1000/mm; LFTs > 3x upper limit; creatinine > 2 mg/dL; diastolic BP < 60 or > 110mmHg; EKG QTc > 475 msec.
• In regard to vulnerable patient populations, persons with dementia, minors (<age 19), the elderly (>age 65), prisoners and the terminally ill are excluded.

No sharing of individual participant data

Adverse events were collected for the 12 weeks of active study participation; Serious adverse events were collected for the 12 weeks of study and one additional post-study month.

This study was limited by both the small number of subjects enrolled and its open-label design.

Average dose of asenapine was 13.6 ± 6.4 mg/d; at 12-weeks 15.9 ± 4.9 mg/d.