Pharmacological Management of Post-Traumatic Stress Disorder; A Qualitative Analysis of ClinicalTrials.gov

Introduction

Post-traumatic stress disorder (PTSD) is a disabling illness and persistent mental health condition that arises following exposure to variety of traumatic life events such as violence, natural disasters, or serious accidents.^1,2 Trauma triggers an immediate activation of the sympathetic nervous system, resulting in an adrenaline surge and a series of physiological changes such as increased heart rate, elevated blood pressure, and the secretion of cortisol and other stress-related hormones.^3–5 In individuals with PTSD, the hypothalamic–pituitary–adrenal axis often becomes dysregulated, showing increased corticotropin-releasing hormone levels, lower baseline cortisol, and heightened sensitivity to feedback inhibition.^6–8 The disorder is characterized by a constellation of symptoms including re-experiencing of the trauma, sleep disturbances, irritability, fear and perceived life threat, and avoidance behaviours.^9–12 These symptoms can lead to significant functional impairment and a diminished quality of life.^13,14 Global epidemiological studies estimate that PTSD occurs in 5–10% of the population and is twice as common in women as in men.^15–17

Pharmacological management of PTSD has been a central component of treatment, particularly for individuals who do not respond first-line trauma-focused psychotherapy.^18,19 Selective serotonin reuptake inhibitors (SSRIs), such as sertraline and paroxetine, are the only medications approved by the US Food and Drug Administration (FDA) for the treatment of PTSD as first-line therapy.^20,21 However, in clinical practice, a wide range of pharmacological agents is used to target specific symptom clusters or comorbidities. These include antidepressants, antipsychotics, anxiolytics, and agents targeting sleep disturbances or neuroendocrine dysregulation.^22–25

Despite the widespread use of PTSD management which includes pharmacological and psychotherapy managements, the evidence supporting their effectiveness and long-term safety remains inconsistent. Clinical trials have found mixed results, and many patients experience only partial symptom relief or discontinue treatment due to adverse effects. Moreover, most existing trials are limited to pre-marketing (phase 2 and 3) studies, often with strict inclusion criteria that may not reflect real-world clinical populations. As a result, there is a pressing need to understand the effectiveness and safety of pharmacological treatments in broader, more diverse populations through post-marketing (phase 4) clinical trials.

Phase 4 trials provide an opportunity to evaluate medications under real-world conditions, offering insights into long-term outcomes, comparative effectiveness, and treatment adherence. The ClinicalTrials.gov registry, maintained by the US National Library of Medicine, serves as a comprehensive public database of registered clinical studies worldwide. It allows researchers to systematically access and analyse data on completed and ongoing trials, including those targeting PTSD.

To my knowledge, no prior study has systematically examined only phase 4 interventional PTSD pharmacotherapy trials. This focus allows us to capture real-world effectiveness and safety, representing a novel contribution beyond earlier meta-analyses of mixed trial phases.

While other trial registries exist, many have limited results reporting, variable data formats, or restricted access. The objective of this study is to conduct a qualitative analysis of phase 4 interventional trials focused on the pharmacological treatment of PTSD, as registered in ClinicalTrials.gov. By examining trial characteristics, enrolled populations, interventions, and primary outcomes, this research aims to identify therapeutic patterns and highlight current directions in post-marketing research for PTSD. This analysis will also offer advancement in understanding PTSD areas.

Methods

Study Design and Data Source

This study used a qualitative, descriptive analysis of phase 4 interventional clinical trials targeting post-traumatic stress disorder. The data were extracted from the publicly available ClinicalTrials.gov database. The database provides detailed information on study design, interventions, outcomes, enrolment, and study results. ClinicalTrials.gov was selected as the sole data source due to its comprehensive coverage, standardized reporting format, and publicly accessible results, which support consistent data extraction and analysis.

Eligibility Criteria

Only interventional trials evaluating the effects of pharmacological treatments were considered eligible for inclusion. To be selected, studies had to be designated as phase 4 trials, enrol participants with a primary diagnosis of post-traumatic stress disorder (PTSD), and explicitly investigate a pharmacological agent as the intervention. In addition, trials were required to have publicly available results posted on ClinicalTrials.gov at the time of data collection. Studies were excluded if they were observational in nature, focused solely on non-pharmacological interventions such as behavioural therapies, were incomplete, or lacked posted results.

Search Strategy and Study Selection

A structured search of ClinicalTrials.gov was conducted using the condition term “Post-Traumatic Stress Disorder” combined with the filter for phase 4 studies. The search was limited to completed studies with posted results. A total of 41 eligible studies were identified and exported for analysis. The dataset included trial identifiers (NCT number), study title, intervention type, primary outcome measures, enrolment numbers, sex distribution, study phase, and summary results.

Data Extraction and Variables

Data were manually reviewed and extracted into a structured spreadsheet. Key variables collected included: (1) trial registration number; (2) pharmacological intervention(s); (3) therapeutic class of the drug; (4) primary clinical outcomes; (5) number of enrolled participants; (6) study phase confirmation; and (7) availability of study results. Interventions were categorized by drug class (eg, SSRIs, hypnotics, opioid analgesics, glucocorticoid receptor antagonists) based on the US FDA pharmacologic classification system.

Data Analysis

Descriptive and thematic analysis was used to synthesize findings. Trials were grouped by drug class and primary treatment target. Trends in intervention use, outcome selection, and trial scale (sample size) were identified. No quantitative meta-analysis was conducted due to heterogeneity in outcome measures and intervention designs. Results were presented in tabular form and supplemented by narrative interpretation of emerging pharmacological patterns. Where multiple PTSD outcome measures were reported, priority was given to the primary outcome (eg, CAPS-IV/5, PCL variants). Secondary outcomes (eg, sleep or biomarker data) were used to contextualize but not override the primary efficacy findings.

Ethical Considerations

This study involved the analysis of publicly available secondary data and did not require institutional review board (IRB) approval or informed consent. No individual patient data were accessed.

Results

A total of 41 phase 4 clinical trials focused on pharmacological treatments for PTSD were included (41/41, 100%). All studies were completed and had publicly available results on ClinicalTrials.gov. Table 1 lists key details about NCT number, study title, drug names, therapeutic class, and the number of participants enrolled in each study.

Table 1 Summary of the Included Clinical Trials (Updated from ClinicalTrials.gov on 27th June 2025)

Several medications were evaluated. The most common were paroxetine, prazosin, and eszopiclone. A few trials explored newer or less typical drugs such as mifepristone and d-cycloserine. Table 2 shows how often each drug was used.

Table 2 Frequency of Drugs Used in Phase 4 PTSD Trials

The distribution of the 41 phase 4 clinical trials evaluating pharmacological interventions for PTSD is presented in Figure 1, categorized by sample size. Of the included trials, 16/41 (39.0%) enrolled ≥60 participants, 13/41 (31.7%) enrolled 20–39 participants, 7/41 (17.1%) enrolled 40–59 participants, and 5/41 (12.2%) enrolled fewer than 20 participants. This distribution highlights the predominance of moderately sized post-marketing studies in PTSD research.

Figure 1 Distribution of phase 4 PTSD clinical trials by enrolment size.

The therapeutic drug classes investigated in phase 4 clinical trials for PTSD are summarized in Table 3. Selective serotonin reuptake inhibitors (SSRIs) were evaluated in 4/41 trials (9.8%), enrolling 205 participants in total. Hypnotics were studied in 2/41 trials (4.9%; n = 108), alpha-1 blockers in 2/41 trials (4.9%; n = 109), glucocorticoid receptor antagonists in 2/41 trials (4.9%; n = 220), NMDA modulators in 2/41 trials (4.9%; n = 56), anticonvulsants in 3/41 trials (7.3%; n = 111), and antipsychotics in 3/41 trials (7.3%; n = 113). The remaining 4/41 trials (9.8%; n≈80) tested other drug classes including beta-blockers, tricyclic antidepressants, opioids, and anxiolytics.

Table 3 Distribution of Therapeutic Drug Classes in Phase 4 PTSD Trials

The classification of primary outcome measures across the 41 phase 4 PTSD trials is presented in Table 4. The Clinician-Administered PTSD Scale (CAPS) was used in 20/41 trials (48.8%), the Short PTSD Rating Interview (SPRINT) in 6/41 (14.6%), functional MRI in 5/41 (12.2%), cortisol biomarkers in 4/41 (9.8%), sleep quality metrics in 3/41 (7.3%), and other outcomes in 3/41 (7.3%).

Table 4 Categorization of Primary Outcome Domains

The included trials were stratified by design type and comparator and are tabulated in Table 5. Parallel-group placebo-controlled designs were most common (26/41, 63.4%), followed by single-arm/open-label trials (9/41, 22.0%) and parallel-group active-controlled trials (6/41, 14.6%). In terms of comparator type, 26/41 (63.4%) trials were placebo-controlled, while 15/41 (36.6%) trials used an active comparator or were single-arm in nature.

Table 5 Overview of the Included Phase 4 Interventional Trials for Post-Traumatic Stress Disorder (PTSD), Stratified by Trial Design (eg, Parallel-Group, Single-Arm) and Comparator Type (Placebo, Active Drug, or Open-Label)

Efficacy and Safety by Drug Class

• SSRIs (4/41 trials; n = 205): Primary outcomes mainly CAPS (Clinician-Administered PTSD Scale) and Posttraumatic Stress Disorder Checklist (PTSD Checklist). Results showed moderate but consistent symptom reduction. Long-term side effects included sexual dysfunction and weight gain, occasionally leading to discontinuation.
• Hypnotics (2/41; n = 108): Assessed sleep quality (subjective and actigraphic). Eszopiclone improved sleep latency but did not consistently reduce global PTSD scores. Reported adverse events were residual sedation and dizziness; rare long-term effects included dependence risk.
• Alpha-1 blockers (2/41; n = 109): Outcomes mainly nightmares and sleep quality. Prazosin reduced trauma-related nightmares in some but not all trials. Adverse events included hypotension and dizziness; no unique long-term toxicities reported.
• Glucocorticoid receptor antagonists (2/41; n = 220): CAPS and cortisol biomarkers as outcomes. Mifepristone did not yield consistent CAPS improvement. Reported adverse events included fatigue, hypokalemia; long-term endocrine effects noted in registry reports.
• NMDA modulators (2/41; n = 56): d-Cycloserine and ketamine trials used CAPS and fMRI. Efficacy results were mixed, with transient benefit on memory reconsolidation. Safety concerns included dissociation and psychotomimetic effects; rare urinary toxicity with ketamine.
• Anticonvulsants (3/41; n = 111): Topiramate and lamotrigine reduced some symptom clusters but not global PTSD outcomes. Common adverse effects included cognitive dulling, paresthesia; rare long-term effects were nephrolithiasis (topiramate).
• Antipsychotics (3/41; n = 113): Quetiapine, risperidone, and olanzapine adjunct trials did not show robust superiority over placebo. Adverse effects included metabolic syndrome and sedation. Long-term concerns include weight gain and tardive dyskinesia risk.
• Other single-agent trials (beta-blockers, anxiolytics, tricyclics, opioids): Results were inconsistent, often limited by small samples. Safety data were sparse; long-term effects are rarely reported.

Full details for each trial, including NCT number, title, design type, and comparator type, are provided in Supplementary Table 1.

Discussion

This qualitative analysis of phase 4 clinical trials registered on ClinicalTrials.gov provides an overview of the pharmacological strategies currently evaluated for post-traumatic stress disorder (PTSD). The findings reveal a sustained focus on established medications such as selective serotonin reuptake inhibitors (SSRIs), alongside growing interest in agents targeting novel neurobiological pathways, including the hypothalamic–pituitary–adrenal axis, sleep-related dysfunction, and memory reconsolidation.^6,7,19

The findings align closely with existing meta-analyses, which consistently identify selective serotonin reuptake inhibitors (SSRIs) as first-line pharmacological treatments for PTSD.^21,26,27 SSRIs, including paroxetine and sertraline, were the most commonly studied drug class among the included trials, consistent with their position as the only medications approved by the US Food and Drug Administration (FDA) for PTSD treatment.^23,28,29 Previous clinical evidence has supported their moderate efficacy,^30,31 though treatment outcomes remain suboptimal in chronic and combat-related PTSD cases. This limited efficacy has prompted the exploration of adjunctive therapies and pharmacologic alternatives, as reflected in the range of drug classes represented in post-marketing trials.

Sleep-related disturbances, a persistent symptom in PTSD, are frequently under-addressed by SSRIs. Several included trials evaluated hypnotic agents (eg, eszopiclone) and alpha-1 blockers (eg, prazosin) for their potential to improve sleep quality and reduce trauma-related nightmares.^32–34 These mixed results further support the need for real-world evidence from phase 4 trials.

Interestingly, several trials investigated neuroendocrine modulation strategies. Mifepristone, a glucocorticoid receptor antagonist, was tested in high-enrolment trials, signalling increased research attention on the role of HPA axis dysregulation in PTSD pathophysiology.^35,36 This focus aligns with literature highlighting altered cortisol feedback and glucocorticoid receptor sensitivity in individuals with PTSD.^37,38 These agents may offer therapeutic value, particularly for patients who exhibit biological markers of stress system imbalance. Emerging approaches involving NMDA receptor modulators, such as d-cycloserine, aim to facilitate memory reconsolidation or extinction learning.^39,40 This pharmacological enhancement of fear extinction has been proposed as an adjunct to exposure-based therapies, reflecting a growing interest in combining pharmacologic and psychotherapeutic modalities.^27,41

A notable finding was the variability in outcome measures. While many trials used validated PTSD rating scales such as CAPS and SPRINT, others employed biomarkers like cortisol or neuroimaging techniques such as fMRI. This heterogeneity illustrates the complex symptom domains targeted in PTSD treatment but also highlights the need for standardized assessment tools to enable comparison across trials. Most studies had small sample sizes and were designed as exploratory investigations, typical of phase 4 research. Nevertheless, these trials contribute valuable insights regarding long-term effectiveness, safety, and applicability to routine clinical settings.

Across drug classes, treatment-emergent adverse events were common and often class-specific. SSRIs showed the highest rate of adverse event-related discontinuation (12–18%), mainly due to sexual dysfunction and gastrointestinal symptoms. Hypnotics and alpha-1 blockers reported fewer serious adverse events, though discontinuations occurred in up to 10% of patients due to dizziness or daytime sedation. Antipsychotics carried the greatest metabolic burden, with discontinuation rates exceeding 20% in some trials. Registry records often lacked systematic reporting of serious adverse events, highlighting a key evidence gap. Overall, the risk–benefit balance remains most favorable for SSRIs, but tolerability issues necessitate individualized prescribing.

The novelty of the analysis lies in its exclusive focus on post-marketing trials, providing unique insights into long-term safety and tolerability patterns that complement pre-marketing efficacy studies.

Limitations

This study is limited by heterogeneity in PTSD outcome measures (CAPS-IV vs CAPS-5, PCL variants), small sample sizes in many trials, and incomplete safety reporting in registry data. Non-pharmacological trials were excluded, narrowing the generalizability of findings to pharmacological management only. Reliance on ClinicalTrials.gov results may omit unpublished or non-posted adverse event data.

Conclusion

This study highlights the expanding range of pharmacological strategies investigated for post-traumatic stress disorder. SSRIs continue to form the foundation of treatment, but newer approaches targeting sleep disturbances, neuroendocrine pathways, and memory processing are gaining momentum. The diversity of interventions and outcome measures reflects the complexity of PTSD and the ongoing need for evidence-based, patient-centred treatment options. Further clinical research is essential to clarify therapeutic benefits and inform future practice. Future phase 4 clinical trials should aim to recruit larger sample sizes and adopt standardized outcome measures to enhance the statistical power, robustness, and generalizability of findings.