Background: Intrusions of traumatic memories, hyperarousal, and symptoms of avoidance and psychological numbness are features of post-traumatic stress disorder (PTSD). Selective serotonin reuptake inhibitors (SSRIs) have been shown to be effective in treating this disorder, but studies have shown some inconsistencies in alleviating symptoms across patient types, symptom clusters, or sex of patient. Some symptoms of PTSD are believed to be related to increases in activity in the noradrenergic pathways.
One medication used for serotonin and norepinephrine reuptake inhibition is venlafaxine extended release (Effexor XR), which has been shown to be effective in treating depression, generalized anxiety disorders, social anxiety disorders, and panic disorders. There are few studies that evaluate non-SSRI treatment of PTSD. Davidson and colleagues assessed the safety and effectiveness of venlafaxine in the treatment of PTSD.
The Study: The study included 329 adults from outpatient psychiatric clinics who had histories of symptoms that were consistent with the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., diagnostic criteria for PTSD and that lasted at least six months. In addition, the participants had to meet diagnostic criteria for PTSD on two standardized questionnaires. The participants went though a seven-day washout period before 161 were randomly assigned to a treatment group with venlafaxine extended release (37.5 to 300 mg per day) and 168 were assigned to a placebo group. The trial was 24 weeks in duration with a taper period lasting up to two weeks at the end of the study and post-study evaluation.
Response was assessed using the 17-item Clinician-Administered PTSD Scale (CAPS-SX), which was given at the start of the study and again at weeks 2, 4, 6, 8, 12, 18, and 24. In addition to measuring the change in this scale, secondary outcome measures included number of remissions, time to remission, stress vulnerability, resilience, depression, quality-of-life functioning, and global illness severity.
Results: The venlafaxine group had a significant reduction in CAPS-SX scores at the end of the study compared with the placebo group. The venlafaxine group also had significant improvement in their reexperiencing and avoidance/numbing symptoms compared with the placebo group. There was no difference in hyperarousability.
The remission rate for the venlafaxine group was 50.9 percent, which was significantly better than the placebo group. The venlafaxine group also had significant improvements in all of the secondary outcome measures compared with the placebo group. The adverse events and withdrawal rates were similar between groups.
Conclusion: The authors conclude that venlafaxine extended release is an effective treatment for PTSD and that it was well tolerated during the study.