The Heterogeneity of Posttraumatic Stress Disorder in DSM-5

Abstract

This diagnostic study reports patterns of DSM-5 posttraumatic stress disorder diagnostic presentations from multiple cohorts.

Posttraumatic stress disorder (PTSD) is defined in DSM-5 as the presence of at least 6 of 20 symptoms across reexperiencing, avoidance, alternations in mood and cognition, and hyperarousal categories. This definition results in 636 120 potential clinical presentations of PTSD,¹ which contrasts with nearly all other diagnoses that have much less heterogeneity. The DSM-5 definition has attracted criticism because its expansion from fear-based symptoms may weaken the relevance of exposure-based treatments for PTSD.² Further, research to identify mechanisms and treatments of PTSD is potentially hampered by this heterogeneity. Although the mathematical possibility exists for substantial heterogeneity of PTSD, it is important to determine actual patterns of PTSD to ascertain if concerns about the diversity of PTSD presentations are justified. Accordingly, to our knowledge, this diagnostic study reports the first large-scale investigation of patterns of DSM-5 PTSD diagnostic presentations.

Methods

The sample was derived from multiple cohorts from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS³) and analyzed using R version 4.2 (R Foundation for Statistical Computing) and SPSS version 28 (IBM). Data were collected between October 2012 and June 2019 and analyzed from April to August 2022. This analysis focused on the Pre-Post Deployment Study (PPDS) because it measured DSM-5 diagnoses of PTSD and relied on data collected at 3 and 12 months after troops returned from Afghanistan. It also used data from the Army STARRS Longitudinal Study, which comprised further waves of Army STARSS cohorts. Ethical approval was provided by the Humans Subjects Committees of the Uniformed Services University of the Health Sciences. Following informed consent, participants completed a traumatic events checklist, and then 30-day PTSD symptoms were assessed using the PTSD Checklist–Civilian Version (PCL-C) that was modified to measure the DSM-5 items.⁴ The PCL-C is validated relative to structured clinical interview in Army STARRS.⁵ Endorsement of each symptom was defined as being at least moderate (score ≥2 on a 0-4 rating). This study followed the RECORD reporting guideline.

Results

Of 10 965 participants (mean [SD] age, 31.2 [7.4] years; predominantly male [83.3%] and of White race [73.3%]) across the 4 data sets, there were 17 260 sets of complete PCL data. Of these, 4843 sets of responses yielded a diagnosis of PTSD, derived from 3511 participants. Of the 3511 participants with a PTSD diagnosis on at least 1 assessment, analyses focused on the initial PTSD diagnosis received by each participant. Of the 3511 participants with a PTSD diagnosis, there were 2181 different patterns of symptoms; 1935 (88.7%) occurred only once. That is, 1935 participants (55.1%) who met criteria for PTSD had a unique pattern of symptoms, 8.2% occurred across 2 people, and 2.9% occurred across 3 people (Figure). The most salient symptom pattern for PTSD was global endorsement of all symptoms (13.4%) (Table). The following most common patterns comprised satisfying each of the B cluster (reexperiencing) and C (active avoidance) symptoms, with different symptoms being endorsed in the D (alterations in mood and cognition) and E (arousal) clusters. Notably, 2898 respondents (82.5%) reported intrusive memories, 2378 (67.7%) reported nightmares, and 2004 (57.1%) reported flashbacks; 3190 (95.7%) reported either intrusive memories, nightmares, or flashbacks.

Figure. Proportion of Participants Sharing Their PTSD Profile With Other Participants.

Table. The 20 Most Common Permutations of Symptoms of Participants With PTSD.

Rank	Pattern of endorsed symptomsa																				No. (%)b
	B cluster (1-5)					C cluster (1-2)		D cluster (1-7)							E cluster (1-6)
1	B1	B2	B3	B4	B5	C1	C2	D1	D2	D3	D4	D5	D6	D7	E1	E2	E3	E4	E5	E6	472 (13.4)
2	B1	B2	B3	B4	B5	C1	C2	D1	D2	D3	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	127 (3.6)
3	B1	B2	B3	B4	B5	C1	C2	NP	D2	D3	D4	D5	D6	D7	E1	E2	E3	E4	E5	E6	60 (1.7)
4	B1	B2	B3	B4	B5	C1	C2	NP	D2	D3	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	43 (1.2)
5	B1	B2	B3	B4	B5	C1	C2	D1	D2	NP	D4	D5	D6	D7	E1	E2	E3	E4	E5	E6	27 (0.8)
6	B1	B2	B3	B4	B5	C1	C2	D1	D2	NP	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	26 (0.7)
7	B1	B2	NP	B4	B5	C1	C2	D1	D2	D3	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	16 (0.5)
8	B1	B2	B3	B4	B5	C1	C2	D1	D2	D3	D4	D5	D6	D7	NP	NP	E3	E4	E5	E6	15 (0.4)
9	B1	B2	B3	B4	B5	C1	C2	NP	D2	NP	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	15 (0.4)
10	B1	B2	NP	B4	B5	C1	C2	D1	D2	D3	D4	D5	D6	D7	E1	E2	E3	E4	E5	E6	14 (0.4)
11	B1	B2	B3	B4	B5	C1	C2	D1	D2	D3	D4	NP	NP	NP	E1	E2	E3	E4	E5	E6	13 (0.4)
12	B1	B2	B3	B4	B5	C1	C2	NP	D2	NP	D4	D5	D6	D7	E1	E2	E3	E4	E5	E6	13 (0.4)
13	B1	B2	B3	B4	B5	C1	C2	D1	NP	D3	D4	D5	D6	D7	E1	E2	E3	E4	E5	E6	11 (0.3)
14	B1	B2	NP	B4	B5	C1	C2	NP	D2	D3	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	11 (0.3)
15	B1	B2	B3	B4	B5	C1	C2	D1	NP	D3	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	10 (0.3)
16	B1	B2	B3	B4	B5	C1	C2	NP	D2	D3	D4	D5	D6	D7	E1	NP	E3	NP	E5	E6	10 (0.3)
17	B1	NP	NP	B4	B5	C1	C2	D1	D2	D3	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	10 (0.3)
18	B1	B2	B3	B4	B5	C1	C2	D1	NP	NP	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	9 (0.3)
19	B1	B2	B3	B4	B5	C1	C2	NP	NP	D3	D4	D5	D6	D7	E1	NP	E3	E4	E5	E6	9 (0.3)
20	B1	NP	B3	B4	B5	C1	C2	D1	D2	D3	D4	D5	D6	D7	E1	E2	E3	E4	E5	E6	9 (0.3)

Abbreviations: NP, not present; PTSD, posttraumatic stress disorder.

^a The following most common patterns comprised satisfying each of the B cluster (reexperiencing, with B1 indicating recurrent and intrusive recollections; B2, nightmares; B3, flashbacks; B4, psychological distress to reminders; and B5, physiological reactivity to reminders) and C cluster (active avoidance, with C1 indicating cognitive avoidance and C2, behavioral avoidance) symptoms, with different symptoms being endorsed in the D cluster (alterations in mood and cognition, with D1 indicating dissociative amnesia; D2, persistent negative beliefs about the self or world; D3, excessive self-blame; D4, persistent negative emotional state; D5, diminished interest; D6, detachment; and D7, emotional numbing), and E cluster (arousal, with E1 indicating irritable behavior; E2, reckless behavior; E3, hypervigilance; E4, exaggerated startle; E5, concentration problems; and E6, sleep disturbance).

^b Percentage value based on total number of 3511 participants.

Discussion

This study assessed the proposition that the DSM-5 diagnosis may result in marked heterogeneity of PTSD,¹ with more than half of personnel having a unique PTSD profile. The finding that 95.7% of participants reported either intrusive memories, nightmares, or flashbacks supports propositions of the centrality of reexperiencing symptoms in PTSD⁶ and addresses concerns of the relevance of the evidence of exposure-based therapies in the DSM-5 definition.² We note the most common symptom combination was global endorsement of all symptoms, which may reflect exaggeration of symptoms. This study's conclusions are limited by the absence of structured clinical interviews for PTSD. Future research needs to recognize that the PTSD diagnosis does not reflect a uniform phenotype, and this recognition has important implications for understanding mechanisms that underpin the disorder and the treatments to remediate posttraumatic responses.

Supplement.

Data Sharing Statement