Veterans’ 12-month PTSD and depression outcomes following 2- and 3-week intensive cognitive processing therapy-based treatment

ABSTRACT

Background: Growing evidence indicates that daily delivery of evidence-based PTSD treatments (e.g. Cognitive Processing Therapy (CPT)), as part of intensive PTSD treatment programmes (ITPs), is feasible and effective. Research has demonstrated that a 2-week CPT-based ITP can produce equivalent outcomes to a 3-week ITP, suggesting shorter treatment can also be highly effective. However, the extent to which ITP length and composition impact longer-term outcomes needs further study.

Objective: We examined whether PTSD and depression symptoms 3-, 6-, and 12-months following completion of a 2-week ITP could be considered non-inferior, or equivalent, to those of a 3-week ITP.

Method: Data from 638 veterans who participated in a 2-week CPT-based ITP were evaluated against 496 veterans who participated in a 3-week CPT-based ITP. A Bayes factor approach was used to examine whether PTSD and depression severity outcomes of the 2-week ITP could be considered equivalent to the 3-week ITP.

Results: Participants across both ITPs reported large PTSD (d = 0.98) and moderate to large depression symptom reductions (d = 0.69) from baseline to 12-month follow-up. The PTSD and depression symptom reductions seen in the 2-week ITP were determined to be equivalent to those of the 3-week ITP.

Conclusions: Low follow-up completion was a limitation. Future research might replicate the present findings using samples with greater follow-up rates and explore whether adjunctive services impact other relevant constructs, such as quality of life and functioning.

Highlights

• This study demonstrated that intensive PTSD treatment programmes for veterans can produce large and lasting PTSD and depression symptoms reductions.

• A 2-week intensive PTSD treatment programme that offered 37 fewer clinical hours was just as effective as a 3-week programme for veterans, with lasting symptom improvement up to 12 months after treatment.

• The 2-week programme focused primarily on individual Cognitive Processing Therapy delivered twice per day whereas the 3-week programme combined individual and group CPT and had a much larger number of adjunctive services.

Cognitive Processing Therapy (Resick et al., 2017) is a first-line evidence-based trauma-focused cognitive behavioural therapy for PTSD (Department of Veterans Affairs, 2023). Individuals who undergo CPT generally report large reductions in PTSD, depression, and co-occurring symptoms that can be maintained long-term (Resick et al., 2012). Mounting research supports its feasibility and effectiveness when delivered daily (Held, Kovacevic, et al., 2022) or as part of intensive PTSD treatment programmes (ITPs) that combine CPT with adjunctive services (e.g. psychoeducation and wellness; Bryan et al., 2022; Held, Smith, et al., 2022).

We previously reported that veteran’s PTSD and depression symptom reductions between a 2-and-3-week CPT-based ITP were non-inferior, despite a meaningful difference in clinical service hours (Held, Smith, et al., 2022), and that most veterans would have benefited equally from the 2-week programme. One distinction between the two programmes lies in their emphasis. The 2-week ITP prioritised individual CPT, offering fewer adjunctive services compared to the 3-week ITP. The lack of observed differences in outcomes between programmes may suggest a trade-off between the specificity of treatment focus and the breadth of services provided. Moreover, there were no significant outcome differences based on demographic characteristics or primary index trauma (i.e. combat vs. military sexual trauma; Held, Smith, et al., 2022). Although prior research has shown that veterans who participated in the 3-week ITP were generally able to maintain their treatment gains (Held et al., 2020), it remains unclear whether the same is true for those who completed the less comprehensive 2-week ITP.

To address questions about the longer-term maintenance of symptom reduction following ITP completion, we tested whether PTSD and depression symptoms at 3-, 6-, and 12-months following a 2-week ITP could be considered equivalent to those of a 3-week ITP. The hypothesis surrounding equivalence was based on our prior research demonstrating non-inferior symptom improvement immediately following ITP completion (Held, Smith, et al., 2022).

1. Method

1.1. Participants

Data from 638 veterans who participated in a 2-week CPT-based ITP and 496 veterans who participated in a 3-week CPT-based ITP at the Road Home Program at Rush University Medical Center in Chicago, Illinois were included in this study. Data from the 2-week ITP was collected from June 2020-September 2023 and from April 2016-March 2020 for the 3-week ITP.

Participants in the 2-week programme were on average 44.5 years old (SD = 10.0) and identified as 52.3% male and 64.1% White. Participants in the 3-week programme were on average 41.3 years old (SD = 9.4) and identified as 65.1% male and 67.4% White.¹ Additional demographic characteristics may be found in Table 1.

Table 1.

Demographic characteristics by programme and cohort type.

	2-Week ITP			3-Week ITP
Variable	n	%	M (SD)	n	%	M (SD)	p
Age	638		44.47 (10.00)	496		41.30 (9.42)	<.001
Sex
Male	334	52.35		323		65.12	<.001
Ethnicity
Not Hispanic or Latino	523	81.97		394		79.43	.215
Race							.105
American Indian/Alaskan Native	5	0.78		10	2.02
Asian	21	3.29		6	1.21
Black or African American	142	22.26		99	19.96
Native Hawaiian/Pacific Islander	9	1.41		3	0.60
Other	52	8.15		44	8.87
White	409	64.11		334	67.39
Cohort Type							<.001
Combat	333	52.19		323	65.12
MST	305	47.81		173	24.88
Military Service Branch							<.001
Air Force	78	12.26		42	8.54
Army	351	55.02		325	66.01
Coast Guard	7	1.10		3	0.61
Marines	94	14.73		76	15.45
Navy	107	16.77		46	9.35
Service Era							<.001
Post-9/11	528	82.76		496	89.91
Deployed							<.001
Yes	435	68.18		392	79.03

Note. Sex refers to biological sex.

1.2. Programme overview

Individuals with a clinician-confirmed diagnosis of PTSD were enrolled in either a combat trauma or military sexual trauma cohort based on their index trauma. Ineligibility criteria included active mania or psychosis, severe substance use or dependence, active suicidality (i.e. indicated active plan with intent) or homicidality within the past 60 days. Following treatment, all participants received referrals and were encouraged to continue care in their local area. More information regarding these treatment programmes may be found in previously published research (Held, Smith, et al., 2022).

1.2.1. 2-week. Intensive PTSD treatment program

The 2-week ITP consisted of 67 h of direct clinical care. Individuals received 16 50-minute individual CPT sessions, 4 mindfulness group sessions, 7 cognitive restructuring or emotion regulation skill-focused groups, and 5 group art therapy sessions.

1.2.2. 3-week. Intensive PTSD treatment program

The 3-week ITP consisted of 104 h of direct clinical care. Individuals received 14 50-minute individual CPT sessions, 13 90-minute group CPT sessions, 13 group mindfulness sessions, 12 group yoga sessions, 4 group art therapy sessions, and 19 additional educational classes on a variety of topics, such as communication, substance use, and sleep.

1.3. Procedures

Study procedures were approved by the Institutional Review Board with a waiver of consent as all assessments were collected as part of routine clinical care. Data was collected at baseline and on the final day of treatment as well as 3-, 6-, and 12-months after treatment. Participants received three reminders and $20 compensation for each completed follow-up survey.

1.4. Measures

1.4.1. Demographic and military characteristics

During intake, participants reported their age, biological sex, race, ethnicity, deployment history, and service era.

1.4.2. The PTSD checklist for DSM-5 (PCL-5)

The PCL-5 (Bovin et al., 2016; Weathers et al., 2013) is a 20-item self-report measure of PTSD symptom severity. Participants were asked to rate the PCL-5 based on the index trauma addressed during CPT. The PCL-5 was administered at baseline, post-treatment, and 3-, 6-, and 12-month follow-up. Baseline and follow-up assessments measured symptom severity over the past month; post-treatment symptom severity was assessed over the past week. Cronbach’s alphas in the 2-week and 3-week samples ranged from .92 to .96 and .89 to .96, respectively.

1.4.3. Patient health questionnaire (PHQ-9)

The PHQ-9 (Kroenke et al., 2001) is a 9-item self-report measure of depression symptoms over the past two weeks. The PHQ-9 was administered at baseline, post-treatment, and at 3-, 6-, and 12-month follow-up. Cronbach’s alphas in the 2-week and 3-week samples ranged from .83 to .87 and .80 to .88, respectively.

1.5. Statistical analysis

Effect sizes for outcomes across time were assessed using Gibbons’ variant of Cohen’s d for repeated measures (Gibbons et al., 1993). Comparisons of baseline demographic characteristics for those who did and did not complete follow-up surveys used multiple logistic regression predicting missingness at 12-month follow-up. To examine whether the 2-week ITP could be considered equivalent to the 3-week ITP in outcomes during follow-up, we used a Bayes factor approach (van Ravenzwaaij et al., 2019). This approach determines whether outcomes can be considered equivalent within a designated equivalence margin via computation of Bayes factors that quantify the likelihood of the hypothesis that the groups are equivalent within the specified margin relative to the hypothesis that they are not. This represents the degree to which the data support equivalence over superiority (for review see van Ravenzwaaij et al., 2019). Similar to our previous analyses of programme outcomes (Held, Smith, et al., 2022), we used conservative 5-point margins for PCL-5 scores, and 3-point margins for PHQ-9 scores. This approach was also applied to assess whether clinical outcomes at baseline and follow-up timepoints could be considered equivalent across those who did, or did not, complete later follow-up surveys. Analyses and figures were completed in R version 4.3.1 using the Tidyverse and baymedr packages.

2. Results

At 3-month follow-up, 51.05% and 50.79% of participants who completed the 2- and 3-week ITPs completed the surveys, 43.29% and 39.78% at 6-month follow-up, and 33.05% and 25.62% at 12-month follow up, respectively. Females (p = .004), married participants (p = .025), and those in the 2-week programme (p = .041) were more likely to complete 12-month follow-up surveys. Serving after 11 September 2001 (p = .365), age (p = .558), education (p = .081), race (p = .222), ethnicity (p = .747), and deployment status (p = .790) were not significantly associated with completing 12-month follow-up assessments. Equivalence testing using the Bayes factor approach indicated that the hypothesis that PTSD severity at baseline, post, and 3-month and 6-month follow-up was equivalent between those who did and did not complete 12-month follow-up surveys was between 15 and 8000 times greater than the likelihood of that either programme was higher in PTSD severity at these timepoints. Similarly, the likelihood of the hypothesis that those who did and did not complete 12-month follow-up surveys were equivalent in depression severity across programme and follow-up timepoints was true was between 470 times greater and over one million times greater than that of the hypothesis that depression severity was greater for either programme. This suggests that missingness is unlikely to be associated with severity of clinical outcomes before or after ITP completion.

Effect sizes for change in PCL-5 (d = 1.26) and PHQ-9 (d = 0.91) reflected large improvements from baseline to post-treatment, and moderate to large improvements from baseline to 12-month follow-up (d = 0.98 and d = 0.69, respectively). The percentage of veterans experiencing symptom worsening in PTSD severity from post until follow-up was 40.38% at 3-months, 44.60% at 6-months, and 46.62% at 12-months. However, effect sizes for symptom worsening from post-treatment to 12-month follow-up were small (PCL-5: d = −0.28, PHQ-9: d = −0.17), indicating treatment gains were mostly maintained (see Figures 1 and 2). Bayes factor analysis indicated that the hypothesis of equivalence of PTSD severity at 3-month follow-up was over 2,000 times more likely than that of superiority of the 3-week programme. This support for the equivalence hypothesis was true across all follow-up timepoints (see Table 2). Similarly, the hypothesis of equivalence of depression severity at 3-month follow-up was over thirty million times more likely than that of superiority of either programme and remained far more likely across all timepoints (see Table 2).

Figure 1.

PTSD symptom severity over time by programme length.

Figure 2.

Depression symptom severity over time by programme length.

Table 2.

Non-inferiority results across follow-up timepoints.

Outcome	2-week programme M (SD)	2-week programme n	3-week programme M (SD)	3-week programme n	BF*
PCL-5 3m	37.82 (19.30)	314	37.39 (17.35)	233	2.30e + 3
PCL-5 6m	39.96 (19.55)	265	40.79 (17.47)	181	466.94
PCL-5 12m	38.29 (18.94)	201	39.32 (18.05)	120	130.50
PHQ-9 3m	12.67 (6.76)	314	12.59 (6.54)	233	3.11e + 7
PHQ-9 6m	12.73 (6.71)	265	13.32 (6.56)	181	5.23e + 4
PHQ-9 12m	12.44 (6.54)	201	12.12 (6.35)	120	2.54e + 4

Note. BF = Bayes Factor. *Represents the likelihood that the data support an equivalence hypothesis relative to that of superiority of one programme.

3. Discussion

Extending previous work (Held, Smith, et al., 2022), the current study found that changes in PTSD and depression symptom severity following the 2-week ITP can be considered equivalent to the 3-week programme up to 12 months. Findings should be interpreted with some caution, however, given low follow-up survey completion rates, with 28.58% of participants completing 12-month follow-up surveys.

Participation in both programmes was associated with large symptom reductions from baseline to 12-month follow-up, highlighting that veterans appear to be able to generally maintain the gains they make during shorter treatment programmes. It is possible that the 2-week programme’s emphasis on individual CPT may expedite time taken to work through traumas and achieve comparable longer-term PTSD and depression symptom reductions. However, the 3-week programme’s broader approach may offer benefits in other areas, such as quality of life, which were not assessed in this study. The findings reported here are comparable to those observed in ITPs utilising other evidence-based PTSD treatments, such as Prolonged Exposure, Eye Movement Desensitisation and Reprocessing, and their combination (e.g. Van Woudenberg et al., 2018; Voorendonk et al., 2020). Although effect sizes reported in these studies are slightly larger compared to the present study, it is important to note the present study focused on veterans, which have been shown to respond less favourably to evidence-based PTSD treatments (Straud et al., 2019).

Immediately following the completion of both ITPs, participants reported small symptom increases of approximately three and one points on the PCL-5 and PHQ-9, respectively, which may be associated with readjustment to their home environments (Held et al., 2020). Following this relatively small increase, symptom severity remained largely stable. The nearly identical patterns of improvement during and following two distinct ITPs lend support that some minimal symptom worsening is to be expected prior to symptom stabilisation, as has been observed in other non-CPT ITPs (Yasinski et al., 2022). It is important to note that all individuals were referred to relevant aftercare services (e.g. continued individual therapy) regardless of the progress made during treatment, which may have supported further integration and utilisation of acquired skills.

This study has several limitations. The two ITPs took place over different time periods, impacting the comparability. Given that the sample was drawn from a routine clinical programme rather than a research trial, follow-up survey completion was variable, with rates as low as 28.58% at the 12-month timepoint. As is common in routine clinical care, individuals were provided with general resources and referral information, but the programme did not systematically follow-up with participants to evaluate whether, and to what extent, they made use of the resources. This also prevented us from determining the extent to which the reported symptoms during follow-up may have been associated with variables such as engagement in trauma-focused aftercare services versus ITP participation. Relatedly, we were unable to determine the extent to which CPT alone contributed to individual symptom improvement and maintenance of gains. It is possible that adjunctive services may have been beneficial for improving areas not assessed in this study, such as quality of life or functioning, which future research should examine. Finally, differences in missingness were found at follow-up, indicating that missingness was not completely at random (MCAR). This raises the possibility that missingness could be associated with unmeasured variables or outcomes of interest. However, results indicate that missingness at final follow-up measurements was unlikely to be associated with outcomes, as outcomes were demonstrated to be equivalent within the equivalence margins selected irrespective of final assessment completion.

Overall, this study supports the longer-term effectiveness of CPT (Resick et al., 2012) by demonstrating that participation in ITPs, may facilitate lasting PTSD and depression symptom reductions. Importantly, ITP length and composition did not influence long-term outcomes; the amount of individual CPT may be an important factor for symptom change and maintenance of gains, which aligns with prior research (Bryan et al., 2022; Resick et al., 2012). Findings suggest that a focus on individual CPT may permit the reduction in adjunctive services and group CPT without losing effectiveness. Future research needs to replicate these findings using studies with better follow-up data. Moreover, studies that rigorously evaluate the role of aftercare are needed; it will be critical to study not only whether aftercare is needed, but also whether specific types of aftercare may better maximise benefits for certain individuals.

Funding Statement

Philip Held receives grant support from Wounded Warrior Project®, the Department of Defense [grant number W81XWH-22-1-0739], and the Agency for Healthcare Research and Quality [grant number R21 HS028511] and the Justice Advisory Council of Cook County, IL. Brian Klassen receives grant support from Wounded Warrior Project®; The content is solely the responsibility of the authors and does not necessarily represent the official views of Wounded Warrior Project®, the Department of Defense, the Agency for Healthcare Research and Quality, or any other funding agency. All other authors declare that they have no competing interests.

Data availability statement

The datasets used in the current study are not publicly available. Datasets can be obtained from the corresponding author upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).