Despite earlier reports suggested that serotonin more specific agents are more effective than other classes, the current evidence base of controlled trials is unable to demonstrate superior efficacy or acceptability for any particular medication class, and even the analysis of drop-out rates does not confirm superior tolerability of SSRIs over other classes.
The majority of performed clinical trials lasted from 8 to 12 weeks. The appropriate duration of the trial in PTSD is still doubtful. Despite duration of trial of 2-3 months is a kind of a standard in clinical trials in psychiatry, there is some evidence that longer duration may be more appropriate in clinical trials in PTSD. In a 24-weeks study by Londborg et al. which was continuation of initial 12-weeks of sertraline treatment , it was found that the huge majority of patients (92%) who had responded during an initial 12 weeks of treatment continued to respond in additional 6 months. On the other side, over the half (54%) of the patients who had not responded in initial 12 weeks of sertraline treatment were responders in the prolonged phase. It is of particular interest that delayed treatment response was associated with a higher severity of baseline PTSD symptoms.
Although duration of majority of trials in psychiatry is conventionally set to 12 weeks, clinical trials in PTSD may require the acute phase of treatment to go beyond initial 12 weeks of treatment, especially if the trial includes more severely ill patients.
7. Efficacy in Relation to Baseline or Symptom Characteristics
It difficult to find any clinical trial in PTSD showing balanced effect on all cluster of symptoms.
The imipramine study by Kosten et al. displayed decrease of intrusive symptoms relative to placebo, but no imipramine benefit was observed for avoidance symptoms. The same was found in a study with phenelzine.
The largest trial with fluoxetine shown a significantly greater response to fluoxetine versus placebo, significantly greater response on the intrusive cluster, and the hyperarousal cluster, but only a trend for the avoidance cluster. Finding of interest is also that having combat-related trauma and being young were associated with significantly greater improvements. As with SSRIs, in treatment with novel antidepressants the response was better in patients who experienced civilian trauma.
Sertraline was evaluated by large trial of Brady et al. in 187 patients. Avoidance, numbing and hyperarousal clusters shown significant improvement in a 12 week-period, but re-experiencing cluster did not. Post hoc analyses in sertraline trial displayed a significant difference in women. However, subsequent analyses did not confirm a gender effect.
Better effect of medication on intrusion than on avoidance symptoms was also displayed in meta-analysis by Stein et al. (2005): summary statistics of trials show that weighted mean difference for intrusion on the Impact of Events Scale was -3.81, while for avoidance cluster it was -3.31.
Therefore, all major clinical trials in PTSD displayed some differences in relation to baseline characteristics of study population or differences in efficacy by symptom clusters.
Antidepressants have the largest database in relation to randomized clinical trials in PTSD. Despite medications belonging to that class are primarily aimed to treat depressive symptoms, meta analysis of RCTs shown that the effect size in treating anxiety symptoms present in PTSD patients was considerably higher than the effect size on treating depressive symptoms. This may suggest that depressive symptoms within PTSD are more difficult to treat or are driven by different mechanism. Southwick et al. (1994) in their meta-analysis of trials where patients were treated with antidepressants for comorbid PTSD and major depressive disorder had the same assumption and have indicated that PTSD symptoms responded independently of the antidepressant effect.
With respect to a substantial proportion of patients who do not respond to pharmacological treatment, and considering assumptions that phenomenology of PTSD is heterogeneous, it remains essential to investigate if certain treatments are more effective for particular symptom sets or for some subgroup of PTSD patients.
Was this article helpful?
Tips And Tricks For Relieving Anxiety... Fast Everyone feels anxious sometimes. Whether work is getting to us or we're simply having hard time managing all that we have to do, we can feel overwhelmed and worried that we might not be able to manage it all. When these feelings hit, we don't have to suffer. By taking some simple steps, you can begin to create a calmer attitude, one that not only helps you feel better, but one that allows you the chance to make better decisions about what you need to do next.