The network approach to posttraumatic stress disorder: a systematic review

Figures & data

Figure 1. PRISMA flow diagram

Table 1. Characteristics of cross-sectional network studies of PTSS

First author, year:	Armour et al., 2017	Bartels et al., 2019	Bartels et al., 2019	Benfer et al., 2018	Benfer et al., 2018	Benfer et al., 2018	Birkeland & Heir, 2017	Birkeland et al., 2017	Birkeland et al., 2017
Study participants
Type of sample	Veteran	Clinical	Clinical	Community	Community	Community	Community	Community	Community
Type of trauma	Lifetime	Lifetime	Lifetime^a	MVA	Sexual assault	Sudden death	Mass violence	Mass violence	Mass violence
Mean time since trauma	21.5 y	NA	NA	NA	NA	NA	10 m	10 m	10 m
% probable PTSD	28	38	NA	12	25	13	24	100^d	100^d
Mean age	54	13	12^a	20^b	20^b	20^b	45	NA	NA
Age range	21–89	7–17	NA	NA	NA	NA	NA	NA	NA
% females	13	66	59	100	100	100	61	0	100
Measurement
Version of DSM	DSM-5	DSM-5	DSM-5	DSM-5	DSM-5	DSM-5	DSM-IV	DSM-IV	DSM-IV
Measure used	PCL-5	CATS	CATS-caregiver	PCL-5	PCL-5	PCL-5	PCL-S	PCL-S	PCL-S
Statistics
Number of nodes	20	20	20	20	20	20	17	17	17
N	221	475	424	226	222	106	190	105	270
N/nodes	11.1	23.8	21.2	11.3	11.1	5.3	11.2	6.2	15.9
Correlation	Polychoric	NA	NA	Polychoric	Polychoric	Polychoric	Polychoric	Polychoric	Polychoric
Regularization	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO
Stability Analysis	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
CS- Betweenness	0.05	0.05	0.05	NA	NA	NA	0.05	0	0.12
CS- Closeness	0.13	0.28	0.20	NA	NA	NA	0.21	0	0.28
CS- Strength	0.36	0.67	0.52	0.10	0.10	0.07	0.28	0.12	0.52
Significance testing	Yes	Yes	Yes	Yes^c	Yes^c	Yes^c	Yes	Yes	Yes
Reproducability
Preregistration	No	No	No	No	No	No	No	No	No
Open data	Yes	No	No	No	No	No	No	matrix	matrix
Included script	Yes	No	No	No	No	No	No	Yes	Yes
Open Access	Yes	No	No	No	No	No	Yes	Yes	Yes
First author, year:	Bryant et al., 2017	Bryant et al., 2017	Cao et al., 2019	Cao et al., 2019	Epskamp et al., 2018	Fried & Cramer, 2017	Fried et al., 2018	Fried et al., 2018	Fried et al., 2018
Study participants
Type of sample	Community	Community	Community	Community	Clinical	Clinical	Clinical	Clinical	Veteran/Clinical
Type of trauma	Traumatic injury	Traumatic injury	Natural disaster	Natural disaster	Lifetime	Lifetime^f	Lifetime	Lifetime	Lifetime
Mean time since trauma	7 d	12 m	2.5 y	2.5 y	NA	NA	NA	NA	NA
% probable PTSD	0	10	41	41	80	NA	68	100	59
Mean age	38	38	13	13	39^e	NA	47	35.6	36.2
Age range	18–70	18–70	12–16	12–16	NA	NA	17–74	18–61	21–76
% females	26	26	0	100	100	100	36	72	5
Measurement
Version of DSM	DSM-IV	DSM-IV	DSM-IV	DSM-IV	DSM-IV	DSM-IV	DSM-IV	DSM-IV	DSM-IV
Measure used	CAPS	CAPS	UCLA	UCLA	PSS-SR	NA	HTQ	PSS	PCL
Statistics
Number of nodes	17	17	17	17	17	17	16	16	17
N	1138	852	373	495	359	180 and 179	526	365	926
N/node	66.9	50.1	21.9	29.1	21.1	10.6 and 10.6	32.9	22.8	54.5
Correlation	NA	NA	Polychoric	Polychoric	Polychoric	NA	Polychoric	Polychoric	Polychoric
Regularization	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO
Stability Analysis	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes
CS- Betweenness	NA	NA	NA	NA	0.05	NA	0.21	0.13	0.11
CS- Closeness	NA	NA	NA	NA	0.05	NA	0.36	0.28	0.13
CS- Strength	NA	NA	0.52	0.59	0.44	NA	0.60	0.59	0.75
Significance testing	No	No	Yes	Yes	Yes	No	Yes	Yes	Yes
Reproducability
Preregistration	No	No	No	No	No	No	No	No	No
Open data	No	No	Yes	Yes	Yes	Yes	Matrix	Matrix	Matrix
Included script	No	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Open Access	No	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
First author, year:	Fried, 2017b	McNally et al., 2017	McNally et al., 2015	Mitchell et al., 2017	Moshier et al., 2018	Moshier et al., 2018	Phillips et al., 2018	Phillips et al., 2018	Phillips et al., 2018
Study participants
Type of sample	Clinical	Clinical	Community	Veteran	Veteran	Veteran	Veteran/Clinical	Veteran/Clinical	Veteran/Clinical
Type of trauma	Lifetime	Childhood sexual abuse	Natural disaster	Combat-related	Lifetime	Lifetime	Combat/lifetime	Combat/lifetime	Combat/lifetime
Mean time since trauma	NA	NA	5.5 y	NA	301 m	301 m	NA	NA	NA
% probable PTSD	100	NA	38	63	72	72	100	0	NA
Mean age	NA	41	45	41^h	55	55	36^h	37	37
Age range	18–79	NA	18–75	NA	NA	NA	21–66	21–66	21–66
% females	42	84	74	51^h	5	5	19^h	21	24
Measurement
Version of DSM	DSM-IV	DSM-IV	DSM-IV	DSM-5/ICD11	DSM-5	DSM-5	DSM-IV	DSM-IV	DSM-IV
Measure used	HTQ	PSS. PCL-C	PCL-C	PCL-5	CAPS-5	PCL-5	DTS	DTS	DTS
Statistics
Number of nodes	17	17	17	20	20	20	17	17	17
N	965	179	362	689	378	378	138	138	639
N/node	56.8	10.5	21.3	34.4	18.9	18.9	8.1	8.1	37.6
Correlation	Polychoric	NA	NA	NA	Polychoric	Polychoric	Polychoric	Polychoric	Polychoric
Regularization	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO
Stability Analysis	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes
CS- Betweenness	0.05	0.13	NA	0.21	NA	NA	<0.50	<0.50	NA
CS- Closeness	0.13	0.05	NA	0.13	NA	NA	<0.50	<0.50	NA
CS- Strength	0.52	0.13	NA	0.44	0.52	0.60	<0.50	<0.50	NA
Significance testing	Yes	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes
Reproducability
Preregistration	No	No	No	No	No	No	No	No	No
Open data	Matrix	Yes	Yes^g	No	Matrix	Matrix	Matrix	Matrix	Matrix
Included script	Yes	Yes	Yes	No	No	No	Yes	Yes	Yes
Open Access	Yes	Yes	Yes	No	No	No	Yes	Yes	Yes
First author, year:	Phillips et al., 2018	Ross et al., 2018	Russell et al., 2017	Russell et al., 2017	Spiller et al., 2017	Sullivan et al., 2018	von Stockert et al., 2018	von Stockert et al., 2018
Study participants
Type of sample	Veteran/Clinical	Veteran/Clinical	Community	Community	Clinical	Community	Veteran	Veteran
Type of trauma	Combat/lifetime	Lifetime	Natural disaster	Natural disaster	Lifetime	Mass violence	Lifetime	Lifetime
Mean time since trauma	NA	NA	3–4 y	3–4 y	NA	3.5 m	25.7 y	28.7 y
% probable PTSD	NA	100	NA	NA	51	NA	8	9
Mean age	35	50	NA	NA	42	22	NA	62.1
Age range	21–66	22–86	8–13	14–18	NA	NA	21–91	23–94
% females	7	4	51	51	30	55	10	10
Measurement
Version of DSM	DSM-IV	DSM-5	DSM-IV	DSM-IV	DSM-5	DSM-IV	DSM-5	DSM-5
Measure used	DTS	PCL-5	UCLA	UCLA	PDS	TRQ	PCL-5	PCL-5
Statistics
Number of nodes	17	20	18	18	20	10	20	20
N	273	331	388	388	151	4639	611	611
N/node	16.1	16.6	21.6	21.6	7.6	463.9	30.6	30.6
Correlation	Polychoric	Polychoric	NA	NA	Polychoric	NA	Spearman	Spearman
Regularization	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO	gLASSO
Stability Analysis	Yes	Yes	No	No	Yes	No	Yes	Yes
CS- Betweenness	NA	0	NA	NA	0.15	NA	NA	NA
CS- Closeness	NA	0.28	NA	NA	0.25	NA	NA	NA
CS- Strength	NA	0.60	NA	NA	0.45	NA	0.75	0.75
Significance testing	Yes	Yes	No	No	Yes	No	Yes	Yes
Reproducability
Preregistration	No	No	No	No	No	No	No	No
Open data	matrix	matrix	No	No	No	No	No	No
Included script	Yes	Yes	No	No	Yes	No	No	No
Open access	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes

^aThis network is based on a sample of caregivers rating symptoms in their children, and the data refer to the children.

^bOverall mean age across all samples in the study

^cNot with ‘standard procedure’.

^dCut off for community samples is used to define PTSD.

^eNot accessible in this paper, but can be found in previous (referred) paper.

^fSample drawn from the same sample as the Epskamp et al. (2018) study.

^gAccessible, but not with initial paper.

^hIn total sample, network is computed based on a subsample.

Figure 2. Top three and bottom three nodes according to node strength. DSM-IV (left), and DSM-5 (right)

Black: Node not present in network*. Fried (2017b): In data 1 and data 2 B4 and B5 were measured as one item, in data 3 and data 4 B4 and B5 were collapsed into a mean. Notes: a = data 1, b = data 2, c = data 3, d = females, e = acute, f = longer-term, g = males, h = younger, I = older, j = subthreshold, k = low exposure, l = high exposure, m = data 4, n = full criteria, o = children, p = caregivers, q = CAPS, r = PCL-5, s = T1, t = T2. Left panel: DSM-IV: B1: recurrent thoughts of trauma, B2: recurrent dreams of trauma, B3: flashbacks, B4: psychological cue reactivity, B5: physiological cue reactivity, C1: avoidance of thoughts of trauma, C2: avoidance of reminders of trauma, C3: memory impairment, C4: diminished interest in activities, C5: feelings of detachment from others, C6: restricted range of affect,C7: sense of foreshortened future, D1: sleeping difficulties, D2: irritability or anger, D3: difficulty concentrating, D4: hypervigilance, D5: exaggerated startle response, C6_2: Numbness sad/anger. Right panel: DSM-5: B1: recurrent thoughts of trauma, B2: recurrent dreams of trauma, B3: flashbacks, B4: psychological cue reactivity, B5: physiological cue reactivity, C1: avoidance of thoughts of trauma, C2: avoidance of reminders of trauma, D1: memory impairment, D2: negative beliefs, D3: distorted blame, D4: persistent negative emotional state, D5: diminished interested in activities, D6: feelings of detachment from others, D7: inability to experience positive emotions/restricted range of affect, E1: irritability or anger, E2: reckless/self-destructive behaviour, E3: hypervigilance, E4: exaggerated startle response, E5: difficulty concentrating, E6: sleeping difficulties.

Figure 3. Number of networks finding edge-weights to be stronger than at least two-thirds of the total computed edge weights in network, DSM-IV (left), and DSM-5 (right)

Left panel: DSM-IV: B1: recurrent thoughts of trauma, B2: recurrent dreams of trauma, B3: flashbacks, B4: psychological cue reactivity, B5: physiological cue reactivity, C1: avoidance of thoughts of trauma, C2: avoidance of reminders of trauma, C3: memory impairment, C4: diminished interest in activities, C5: feelings of detachment from others, C6: restricted range of affect,C7: sense of foreshortened future, D1: sleeping difficulties, D2: irritability or anger, D3: difficulty concentrating, D4: hypervigilance, D5: exaggerated startle response, C6_2: Numbness sad/anger.Right panel: DSM-5: B1: recurrent thoughts of trauma, B2: recurrent dreams of trauma, B3: flashbacks, B4: psychological cue reactivity, B5: physiological cue reactivity, C1: avoidance of thoughts of trauma, C2: avoidance of reminders of trauma, D1: memory impairment, D2: negative beliefs, D3: distorted blame, D4: persistent negative emotional state, D5: diminished interested in activities, D6: feelings of detachment from others, D7: inability to experience positive emotions/restricted range of affect, E1: irritability or anger, E2: reckless/self-destructive behaviour, E3: hypervigilance, E4: exaggerated startle response, E5: difficulty concentrating, E6: sleeping difficulties.

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Data availability statement

The data that support the findings of this study are openly available as supplemental materials in http://osf.io/95es2.