Psychiatry Investig Search


Psychiatry Investig > Volume 20(6); 2023 > Article
Seong, Cho, and Na: Prevalence and Correlates of Comorbid Posttraumatic Stress Disorder in Schizophrenia-Spectrum Disorder: A Systematic Review and Meta-Analysis



Schizophrenia-spectrum disorders and posttraumatic stress disorder (PTSD) share common clinical manifestations, genetic vulnerability, and environmental risk factors. We aimed to conduct a systematic review and meta-analysis of the comorbid prevalence of PTSD among schizophrenia-spectrum disorders.


We performed a meta-analysis to identify possible contributing factors to the heterogeneity among these studies. We systematically searched electronic databases with no restrictions on language of articles.


We extracted 24 samples (18 for current prevalence and 6 for lifetime prevalence) from 22 studies and used a random effects model to estimate the pooled prevalence of PTSD among schizophrenia-spectrum disorders. The current and life prevalence of comorbid PTSD was 10.6% (95% confidence interval [CI]=6.3%-17.3%) and 13.0% (95% CI=5.3%-28.6%), respectively. Studies assessing psychotic experiences/involuntary admission reported the highest prevalence of comorbid PTSD (57.1%, 95% CI=43.6%-59.7%), whereas those assessing various anxiety disorders reported the lowest prevalence (1.1%, 95% CI=1.0%-5.5%). Heterogeneities of the subgroup analysis by similar objectives were largely homogeneous (I2=7.1-34.1). In the qualitative assessment, only two studies (9.1%) were evaluated as having a low risk of bias.


Our results showed that a careful approach with particular attention to assessing PTSD is essential to reliably estimate the prevalence of PTSD comorbid with schizophrenia-spectrum disorders. The reason for the wide discrepancy in the prevalence of comorbid PTSD among the four groups of studies should be addressed in future research.


Schizophrenia is a mental disorder characterized by positive, negative, and cognitive symptoms and often marked by chronic deterioration [1]. Like most other mental disorders, schizophrenia occurs as a result of gene-environment interactions [2-4]. Although a genetic predisposition is considered to play a substantial role in the onset and prognosis of schizophrenia [5], early-life adversity, such as traumatic experiences, influences the ultimate expression of the genetic factors [6,7].
Indeed, patients with schizophrenia commonly report having experienced traumatic events. Previous research indicates that approximately 40% to 80% of patients report a history of traumatic childhood experiences [8]. Traumatic experiences are associated with severe positive, negative, and cognitive symptoms in patients with schizophrenia [8-10], along with an absence of insight into their disease [11]. Patients also experience increased suicidal risk [12], impaired sensory gating [13], and disturbances in brain activity [14]. Posttraumatic stress disorder (PTSD) and schizophrenia also share genetic predispositions; schizophrenia has a small but significantly overlapping polygenetic score with PTSD [15].
However, the relationship between schizophrenia and PTSD may be bidirectional. Prior research has suggested that psychosis, such as that caused by schizophrenia, can result in the onset of PTSD [16,17]. Indeed, psychotic symptoms such as auditory hallucinations with commanding voices could threaten patients who experience them [18,19]. When people first experience psychotic symptoms, they perceive that they are losing control over themselves, and that they are “crazy” and may be forced to be hospitalized involuntarily [18].
Given the possible bidirectional association of traumatic experiences and schizophrenia, it is likely that co-occurring PTSD is common in schizophrenia. As comorbid psychiatric disorders contribute to a poor prognosis of the illness for patients with schizophrenia [20], evaluating the prevalence of comorbid PTSD in schizophrenia is an important priority.
Systematic reviews and meta-analyses conducted to date have not been able to accurately identify the prevalence of PTSD and its correlates in patients with schizophrenia. A meta-analysis first reported that the pooled prevalence of comorbid PTSD in schizophrenia was 12.4% (95% confidence interval [CI]=4.0%-20.8%) [21]. However, there was significant heterogeneity (χ2=294.1, p<0.001) among the included individual studies. As PTSD was not the primary focus of that meta-analysis, possible contributing factors for the heterogeneity were not reported. Two recent systematic reviews have focused on the prevalence of PTSD in schizophrenia [22,23]; however, several aspects of these reviews limit our ability to draw definitive conclusions. For instance, the two systematic reviews included studies that used only self-report instruments for diagnosing PTSD. In addition, there were no considerations for recruitment methods (e.g., consecutive, randomized) and the primary objective of the studies (e.g., measuring the prevalence of various anxiety disorders, specifically focused on PTSD).
In this meta-analysis, we aimed to investigate: 1) the pooled prevalence of comorbid PTSD in schizophrenia-spectrum disorders and 2) potential demographic and clinical moderators that influence the prevalence of PTSD. Given the substantial heterogeneity of the previous studies [21], we hypothesized that the pooled prevalence of comorbid PTSD in schizophrenia-spectrum disorders would depend on the demographic and clinical moderators.


We conducted a meta-analysis and systematic review according to both the Meta-analysis of Observational Studies in Epidemiology guidelines [24] and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines [25].

Inclusion and exclusion criteria

We included observational, cross-sectional, and cohort studies that measured the prevalence of PTSD among patients with schizophrenia. As schizophrenia and PTSD share essential symptoms such as hallucinations, anxiety, and intense fear, distinguishing these disorders requires a cautious approach [26]. Hence, we rigorously set the inclusion and exclusion criteria. First, the proportion of the sample with schizophrenia-spectrum disorders (schizophrenia, schizoaffective disorder, and schizophreniform disorder) was above 70%. When possible, the subpopulation of participants with schizophrenia-spectrum disorder was extracted and used for meta-analysis. Second, all participants were 18 years old or above. Third, only studies that used validated diagnostic and clinical interviewing instruments were included. We excluded studies that assessed participants without validated interviewer-rated diagnostic tools for PTSD. We also excluded studies that included patients at risk for PTSD (e.g., veterans, patients with comorbid substance use disorder).

Literature search strategy

We conducted a systematic literature search of electronic databases (i.e., MEDLINE, Embase, CINAHL, and PsycINFO).
We set the search period to retrieve articles published before February 28, 2022. The search strategy was “posttraumatic stress disorder AND schizophrenia.” There were no language restrictions. We selectively searched the literature cited in the identified articles, along with systematic reviews and relevant news articles.

Study selection

We uploaded the final set of article to Covidence (, an Internet-based program that enables a systematic selection of literature and facilitates independent reviews.
Two authors, KSN and AS, independently screened the titles and abstracts of the literature. KSN and AS obtained full texts for all studies that appeared to be eligible according to the predetermined criteria mentioned above. Potentially eligible studies were also assessed. When there were discrepancies between the two authors, a third author (SEC) resolved any disagreements about the relevance of the literature. If the information contained within a study was insufficient, or there was some uncertainty, one author (SEC) contacted the corresponding author of the study for clarification. If duplicate data were suspected, the study with the larger sample size was selected.

Data extraction

We extracted the number of patients with PTSD comorbid with schizophrenia in each study. If only the percentage of study participants with PTSD was available, we calculated the number of patients with PTSD by multiplying the total sample size by the percentage given. We separately estimated the lifetime and current prevalence of PTSD.

Risk of bias of individual studies

We assessed the risk of bias using instruments developed for the systematic review and meta-analysis of prevalence studies [27].

Data synthesis

We estimated the prevalence of PTSD comorbid with schizophrenia by using an odds ratio with a 95% CI. We used a random effects model to estimate the pooled prevalence. We conducted a test for heterogeneity by using the Q-statistic and I2. Generally, an I2 of 0% indicates no observed heterogeneity, 25% represents low, 50% moderate, and 75% high heterogeneity [28]. In this study, an I2 of ≥50% was considered heterogeneous.
We conducted a subgroup analysis to identify factors contributing to heterogeneity. We conducted a meta-regression to identify the contributing factors for the results of the meta-analysis. Subgroup analysis and meta-regression were conducted on the primary objective, interviewing instruments, diagnostic criteria, and recruitment methods. All meta-analysis processes were conducted using Comprehensive Meta-Analysis software version 3 (Biostat Inc., Englewood, NJ, USA).

Publication bias

Publication bias was visually inspected through a funnel plot. We also statistically estimated the degree of publication bias using Egger’s method [29].

Ethical considerations

The secondary data was collected from databases following clear systemic review guidelines. No personal information was collected and all data was stored electronically in accordance with the Gil Medical Center’s data protection policy. All research was conducted in accordance with Gil Medical Center’s Research Ethics Committee.


Literature search and selection

Figure 1 is a PRISMA diagram showing the process from literature identification to inclusion. Thirty studies underwent a full-text review. One study was excluded because the proportion of patients with schizophrenia-spectrum disorders was less than 70% [30]. Two were excluded because they did not use a structured clinical interview for diagnosing PTSD [31,32]. One was excluded because it included patients under 18 years of age [33]. Two studies were excluded because they only measured non-affective psychotic disorder [34,35]. One study was excluded because a validated structured interview tool was not used for diagnosing psychiatric disorders [36]. One study was excluded because only self-report instruments for diagnosing PTSD were used [37]. Ultimately, 22 studies were included in the meta-analysis and systematic review.

Study characteristics

Table 1 shows the characteristics of the studies included in the systematic review and meta-analysis. Out of 22 studies, 18 studies measured current prevalence and six studies measured lifetime prevalence. Two studies measured both current and lifetime prevalence. Most studies focused on the prevalence of PTSD (n=11), followed by various anxiety disorders (n=5), various psychiatric disorders (n=4), and psychotic experiences/involuntary admission (n=2). Approximately half of the studies (n=12) consecutively recruited participants, whereas half of the studies (n=10) did not mention the recruitment methods. Most studies (n=16) diagnosed PTSD according to DSM-IV criteria [58].

Qualitative assessment

Table 2 presents the qualitative scores of the studies. In the summary item on the overall risk of study bias, only two studies (9.1%) were evaluated as having a low risk of bias, seven (31.8%) were moderate, and 13 (59.1%) were assessed as high risk. Except for one study, Item 10 was largely met (95.4%). Eighteen studies (81.8%) evaluated the study instrument that measured the parameter of interest as valid and reliable (Item 7), and 16 (72.7%) were evaluated as using an acceptable case definition (Item 6). However, only one study included a target population that was a close representation of the national population (Item 1). In addition, only one study reported a response rate (Item 4).


The current prevalence of PTSD comorbid with schizophrenia-spectrum disorder was 10.6% (95% CI=6.3%-17.3%) (Figure 2). The heterogeneity was substantially high (Q=148.9, I2=88.6). The funnel plot of standard error by logit event rate showed that there were substantial small study effects, which means that the results from the small sample size studies unduly influenced the pooled prevalence rate (Figure 3). The funnel plot shows that seven studies were needed to adjust for publication bias.
Six studies examined the lifetime prevalence of PTSD. The lifetime prevalence of PTSD was 13.0% (95% CI=5.3%-28.6%), with substantial heterogeneity (Q=96.0, I2=94.8).

Subgroup analysis and meta-regression

The subgroup analysis for current prevalence of PTSD is presented in Table 3. Unlike the results for the total sample, subgroup analysis shows that studies grouped by similar objectives were largely homogeneous. The I2 statistics were zero in the groups of studies of psychotic experiences/involuntary admission and various anxiety disorder groups. The groups of studies of PTSD (I2=7.1) and various psychiatric disorders (I2=34.1) also had low heterogeneity. The current prevalence of PTSD was widely varied across the four subgroups. Subgroup of psychotic experiences/involuntary admission reported the highest prevalence (57.1%, 95% CI=43.6%-59.7%), which was followed by PTSD (16.9%, 95% CI=14.2%-19.9%), various psychiatric disorders (2.3%, 95% CI=1.0%-5.5%), and various anxiety disorders (1.1%, 95% CI=0.3%-3.3%).
The meta-regression model, which evaluated the impact of the objective of the study (psychotic experiences/involuntary admission, various anxiety disorders, various psychiatric disorders, and PTSD) showed an R2 of 1.0, which means that these variables explain 100% of the total variance in true effects. Recruitment type (R2=0.0), clinical interview conducted (R2=0.42), and diagnostic criteria used (R2=0.45) did not adequately explain the total variance.
Due to the small number of individual studies, subgroup analysis and meta-regression were not conducted for lifetime prevalence of PTSD.


In this study, we conducted a systematic review and meta-analysis of the comorbid prevalence of PTSD among schizophrenia-spectrum disorders. The pooled prevalence of current comorbid PTSD, 10.6% (95% CI=6.3%-17.3%), is slightly lower than that estimated 10 years ago, 12.4% (95% CI=4.5%-20.8%). In contrast with the previous meta-analysis, which estimated the combined lifetime and current prevalence of PTSD [21], we estimated it separately since lifetime prevalence is usually higher than current prevalence. There were no meaningful differences between the two types of prevalence in both previous research and the current results. We suggest that the imbalanced proportion of studies targeting various anxiety or psychiatric disorders caused the non-discrepant results between lifetime and current prevalence. Only one out of eight (12.5%) studies of various anxiety or psychiatric disorders were included in the lifetime prevalence group, but seven out of eight (87.5%) studies of various anxiety or psychiatric disorders were included in the current prevalence group. Hence, the lifetime prevalence of PTSD may have been diluted by studies targeting various psychiatric disorders.
Heterogeneity among studies was high in previous research [21] and in this meta-analysis. Whereas the previous meta-analysis did not report which factors contributed to such high heterogeneity [21], we aimed to identify these factors via subgroup analysis and meta-regression. Our results showed that the prevalence of comorbid PTSD was mostly dependent on the objective of the studies. Studies that estimated the prevalence of various anxiety disorders and psychiatric disorders beyond solely PTSD showed the lowest prevalence (1.1%, 95% CI=0.3%-3.3%), whereas studies that investigated the possible role of psychotic experiences and involuntary admission had the highest prevalence, 51.7% (95% CI=43.6%-59.7%) [16,17]. Studies that focused solely on the prevalence of PTSD reported a prevalence of 16.9% (95% CI=14.2%-19.9%), which is similar to the pooled prevalence rate in the total sample. In the subgroup analysis based on the primary objective of the individual studies, heterogeneity was not revealed to be more prominent. This result means that the prevalence of comorbid PTSD in schizophrenia-spectrum disorder is highly dependent on the primary focus of the individual studies.
There are several reasons for the apparent discrepancy in the prevalence of comorbid PTSD among the four groups of studies. The extremely low prevalence reported among studies of various psychiatric disorders and various anxiety disorders may have arisen from a lack of specific focus on PTSD. Indeed, no studies paid particular attention to the etiology or correlates of the prevalence of PTSD. Because PTSD and schizophrenia often have common etiological factors (e.g., early-life adversity) and clinical symptoms (e.g., hallucinations) [26], the diagnosis of PTSD comorbid with schizophrenia is not merely adding one disease to another. Careful attention is needed to detect PTSD in patients with a schizophrenia-spectrum disorder. Such efforts usually include the use of additional diagnostic tools such as the Impact of Event Scale-Revised [59] and the Harvard Trauma Questionnaire [60] for traumatic experiences and PTSD. However, no studies to date have used any additional instruments specifically designed to assess PTSD [38-44]. Without sufficient information on traumatic experiences and PTSD symptoms, those studies appeared to conclude that there was no comorbid PTSD.
On the other hand, two studies reported a relatively high prevalence of comorbid PTSD (51.7%, 95% CI=43.6%-59.7%) [16,17]. These studies both assessed external factors impacting the prevalence of PTSD, such as traumatic experiences or psychiatric admission. However, this is the only similarity between the two studies. Priebe et al. [16] and Shaw et al. [17] used PTSD-specific diagnostic instruments such as the Clinician-Administered PTSD Scale [61] and PTSD interview [62], respectively. Other factors, such as the recruitment method, diagnostic criteria, and diagnostic tool, could not explain why only these two studies reported a substantial prevalence of comorbid PTSD. However, as shown in one study [16], the severity of PTSD correlated with the severity of psychopathology. As Priebe et al. [16] described, it might be challenging to distinguish symptoms of PTSD from those of schizophrenia. Although psychotic experiences and involuntary admission to a psychiatric ward could induce intense anxiety and fear, which consequently may have led to the onset of PTSD, an excessively high prevalence than other types of traumatic experiences could not be easily understood. Subsequent studies with similar objectives and design should be conducted to confirm the high prevalence of PTSD reported in these two studies.
Unlike previous systematic reviews [22,23], we applied rigorous criteria to exclude risk groups for PTSD, such as those with substance use disorder [63] and veterans [64]. As these populations are prone to PTSD, estimating the prevalence of PTSD among those groups may have led to an overestimation of PTSD in those reviews.
This study has several limitations which should be noted. First, variables related to traumatic events of PTSD, such as type and onset of trauma, were not systematically collected in most of studies. Second, subgroup analysis and meta-regression for the lifetime prevalence of comorbid PTSD could not be measured due to small numbers of individual studies. Third, most of the individual studies were conducted in the Western countries such as the United States and Europe, whereas only three studies were conducted in the Eastern countries (one in India and two in Singapore). Given the cross-cultural sensitivity to the traumatic response [65], more studies from the East Asian countries are needed.
Our meta-analysis has several implications of note. First, studies should primarily focus on PTSD rather than merely including PTSD as one of the various anxiety disorders. Second, studies should obtain supplemental information about PTSD symptoms and history beyond the use of a structured diagnostic interview. For example, a lifetime history of traumatic events should be collected and PTSD-specific rating instruments should be used. Third, transparent reporting of recruitment of participants is recommended for future studies. Only half of all studies (12 out of 24) consecutively recruited participants, whereas others did not mention how they recruited participants.
In conclusion, we showed that the prevalence of PTSD among patients with schizophrenia-spectrum disorders is highly dependent on the objective of the studies. Thus, solely estimating the prevalence of PTSD in schizophrenia-spectrum disorders might lead to a biased conclusion. Before amalgamating the results of individual studies, it is necessary to categorize studies according to the appropriate criteria. Future studies are needed to accurately estimate the prevalence of PTSD among patients with schizophrenia.


Availability of Data and Material

The datasets generated or analyzed during the suty are available from the corresponding author on reasonable request.

Conflicts of Interest

The authors have no potential conflicts of interest to disclose.

Author Contributions

Conceptualization: Anna Seong, Kyoung-Sae Na. Data curation: Anna Seong, Kyoung-Sae Na. Formal analysis: Kyoung-Sae Na. Investigation: all authors. Methodology: all authors. Project administration: Kyoung-Sae Na. Software: Kyoung-Sae Na. Supervision: Kyoung-Sae Na. Validation: Kyoung-Sae Na. Visualization: Kyoung-Sae Na. Writing—original draft: all authors. Writing—review & editing: all authors.

Funding Statement


Figure 1.
Flow doagram of study selection process by PRISMA.
Figure 2.
Forest plot of the prevalence of PTSD among patients with schizophrenia-spectrum disorder.
Figure 3.
Publication bias assessment for the prevalence of PTSD among patients with schizophrenia-spectrum disorder. The white circles represent the actual studies. The black circles represent the imputed studies, which were assumed to have been present if the funnel plot had been symmetrical. The vertical line indicates the pooled log of the relative risk after adjustment for publication bias.
Table 1.
Characteristics of the studies included in the systematic review and meta-analysis
Study Country Objective Recruitment Total N PTSD N Interview Diagnosis Prevalence
Braga et al. [38] (2005) Brazil Various anxiety disorders Consecutive 53 2 SCID DSM-IV Lifetime
Ciapparelli et al. [39] (2007) Italy Various anxiety disorders N/A 98 0 SCID DSM-IV Current
DeTore et al. [45] (2021) United States PTSD N/A 404 20 SCID DSM-IV Lifetime
Halász et al. [46] (2013) Hungary PTSD N/A 125 21 SCID DSM-IV Current
Karatzias et al. [42] (2007) United Kingdom Various psychiatric disorders Consecutive 136 1 SCID DSM-IV Current
Kiran and Chaudhury [47] (2016) India Various anxiety disorders Consecutive 93 1 MINI ICD-10 Current
Neria et al. [48] (2002) United States PTSD N/A 170 17 SCID DSM-III-R Lifetime
Newman et al. [49] (2010) United States PTSD Consecutive 52 22 SCID DSM-IV Lifetime
9 Current
Pallanti et al. [50] (2004) Italy Various anxiety disorders Consecutive 80 1 SCID DSM-IV Current
Peleikis et al. [51] (2013) Norway PTSD Consecutive 292 21 SCID DSM-IV Lifetime
Priebe et al. [16] (1998) Germany Involuntary admission N/A 105 54 PTSD-I DSM-III-R Current
Resnick et al. [52] (2003) United States PTSD N/A 47 6 CAPS DSM-IV Current
Sarkar et al. [53] (2005) United Kingdom PTSD N/A 55 22 PSS-I DSM-IV Lifetime
15 Current
Schäfer et al. [54] (2015) Germany PTSD Consecutive 121 14 SCID DSM-IV Current
Seedat et al. [41] (2007) South Africa Various psychiatric disorders Consecutive 70 3 MINI DSM-IV Current
Shaw et al. [17] (2002) Australia Psychotic experiences Consecutive 42 22 CAPS DSM-III-R Current
Sim et al. [44] (2006) Singapore Various psychiatric disorders Consecutive 142 0 SCID DSM-IV Current
Sin et al. [57] (2010) Singapore PTSD N/A 45 7 CAPS DSM-IV-TR Current
Steel et al. [55] (2011) United Kingdom PTSD N/A 165 30 CAPS DSM-IV Current
Strakowski et al. [40] (1993) United States Various psychiatric disorders Consecutive 10 0 SCID DSM-III-R Current
Tibbo et al. [43] (2003) Canada Various anxiety disorders N/A 30 0 MINI DSM-IV Current
Vogel et al. [56] (2009) Germany PTSD Consecutive 74 11 SCID DSM-III-R Current

PTSD, posttraumatic stress disorder; N, number; N/A, not available; DSM, Diagnostic and Statistical Manual; SCID, Structured Clinical Interview for DSM Disorders; MINI, Mini International Neuropsychiatric Interview; ICD-10, International Classification of Diseases, 10th revision; CAPS, Clinician-Administered PTSD Scale; PTSD-I, PTSD Interview; PSS-I, PTSD Symptom Scale-Interview

Table 2.
Risk of bias of included studies
Study 1. Was the study’s target population a close representation of the national population in relation to relevant variables? 2. Was the sampling frame a true or close representation of the target population? 3. Was some form of random selection used to select the sample, OR was a census 4. Was the likelihood of nonresponse bias minimal? 5. Were data collected directly from the subjects (as opposed to a proxy)? 6. Was an acceptable case definition used in the study? 7. Was the study instrument that measured the parameter of interest shown to have validity and reliability? 8. Was the same mode of data collection used for all 9. Was the length of the shortest prevalence period for the parameter of interest appropriate? 10. Were the numerator(s) and denominator(s) for the parameter of interest 11. Summary item on the overall risk of study bias
Braga et al. [38] (2005) No No No No Yes Yes Yes Yes No Yes High
Ciapparelli et al. [39] (2007) No No Yes No Yes Yes No Yes Yes Yes Moderate
DeTore et al. [45] (2021) Yes Yes Yes No Yes Yes Yes Yes No Yes Low
Halász et al. [46] (2013) No No No No Yes No Yes Yes Yes No High
Karatzias et al. [42] (2007) No No Yes No No Yes Yes No Yes Yes High
Kiran and Chaudhury [47] (2016) No No No No Yes No Yes No Yes Yes High
Neria et al. [48] (2002) No No No No No No No No No Yes High
Newman et al. [49] (2010) No No No No No Yes Yes No No Yes High
Pallanti et al. [50] (2004) No No No No Yes No No No Yes Yes High
Peleikis et al. [51] (2013) No Yes Yes No Yes Yes Yes Yes No Yes Moderate
Priebe et al. [16] (1998) No No No No No Yes Yes Yes Yes Yes High
Resnick et al. [52] (2003) No No No No Yes Yes Yes No Yes Yes High
Sarkar et al. [53] (2005) No No No No Yes Yes Yes Yes No Yes High
Schäfer et al. [54] (2015) No No Yes No Yes Yes Yes Yes Yes Yes Moderate
Seedat et al. [41] (2007) No No No No Yes Yes Yes No Yes Yes High
Shaw et al. [17] (2002) No No Yes No Yes Yes Yes Yes Yes Yes Moderate
Sim et al. [44] (2006) No No Yes No Yes Yes Yes No Yes Yes Moderate
Sin et al. [57] (2010) No No No No Yes Yes Yes Yes Yes Yes Moderate
Steel et al. [55] (2011) No No Yes No Yes Yes Yes Yes Yes Yes Moderate
Strakowski et al. [40] (1993) No No Yes No Yes No No Yes Yes Yes High
Tibbo et al. [43] (2003) No No No No Yes No Yes Yes Yes Yes High
Vogel et al. [56] (2009) No No Yes Yes Yes Yes Yes Yes Yes Yes Low
Table 3.
Subgroup analysis of the prevalence of current PTSD among patients with schizophrenia
Variables N Mean prevalence (%) 95% CI (%) p Q I2
Psychosis/involuntary admission 2 51.7 43.6-59.7 0.917 0.0 0.0
PTSD 8 16.9 14.2-19.9 0.375 7.5 7.1
Various anxiety disorders 4 1.1 0.3-3.3 0.941 0.4 0.0
Various psychiatric disorders 4 2.3 1.0-5.5 0.207 4.5 34.1
Consecutive 10 6.1 2.4-14.4 <0.001 74.7 87.9
Not reported 8 17.2 9.3-29.7 <0.001 62.3 88.8
Diagnostic criteria
DSM-III-R 4 31.8 13.8-57.5 <0.001 28.1 89.3
DSM-IV 13 9.6 6.1-14.9 <0.001 48.2 75.1
ICD-10 1 1.1 0.2-7.2 >0.999 0.0 0.0
Diagnostic interview
CAPS 4 22.6 10.6-41.6 <0.001 24.0 87.5
MINI 3 2.8 1.1-6.9 0.437 1.6 0.0
SCID 9 7.0 3.6-13.0 <0.001 31.1 74.3
PSS-I 1 27.3 17.2-40.4 >0.999 0.0 0.0
PTSD-I 1 51.4 41.9-60.8 >0.999 0.0 0.0

N, number; CI, confidence interval; PTSD, posttraumatic stress disorder; DSM, Diagnostic and Statistical Manual; ICD-10, International Classification of Diseases, 10th Revision; CAPS, Clinician-Administered PTSD Scale; MINI, Mini International Neuropsychiatric Interview; SCID, Structured Clinical Interview for DSM Disorders; PSS-I, PTSD Symptom Scale-Interview; PTSD-I, PTSD Interview


1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: American Psychiatric Association; 2013.

2. Punzi G, Bharadwaj R, Ursini G. Neuroepigenetics of schizophrenia. Prog Mol Biol Transl Sci 2018;158:195-226.
crossref pmid
3. Stilo SA, Murray RM. Non-genetic factors in schizophrenia. Curr Psychiatry Rep 2019;21:100
crossref pmid pmc pdf
4. Lieslehto J, Kiviniemi VJ, Nordström T, Barnett JH, Murray GK, Jones PB, et al. Polygenic risk score for schizophrenia and face-processing network in young adulthood. Schizophr Bull 2019;45:835-845.
crossref pmid
5. Henriksen MG, Nordgaard J, Jansson LB. Genetics of schizophrenia: overview of methods, findings and limitations. Front Hum Neurosci 2017;11:322
crossref pmid pmc
6. Husted JA, Ahmed R, Chow EW, Brzustowicz LM, Bassett AS. Early environmental exposures influence schizophrenia expression even in the presence of strong genetic predisposition. Schizophr Res 2012;137:166-168.
crossref pmid pmc
7. van Os J, Kenis G, Rutten BP. The environment and schizophrenia. Nature 2010;468:203-212.
crossref pmid pdf
8. Hacioglu Yildirim M, Yildirim EA, Kaser M, Guduk M, Fistikci N, Cinar O, et al. The relationship between adulthood traumatic experiences and psychotic symptoms in female patients with schizophrenia. Compr Psychiatry 2014;55:1847-1854.
crossref pmid
9. Popovic D, Schmitt A, Kaurani L, Senner F, Papiol S, Malchow B, et al. Childhood trauma in schizophrenia: current findings and research perspectives. Front Neurosci 2019;13:274
crossref pmid pmc
10. Dauvermann MR, Donohoe G. The role of childhood trauma in cognitive performance in schizophrenia and bipolar disorder - A systematic review. Schizophr Res Cogn 2019;16:1-11.
crossref pmid
11. Pignon B, Lajnef M, Godin O, Geoffray MM, Rey R, Mallet J, et al. Relationship between childhood trauma and level of insight in schizophrenia: a path-analysis in the national FACE-SZ dataset. Schizophr Res 2019;208:90-96.
crossref pmid
12. Mohammadzadeh A, Azadi S, King S, Khosravani V, Sharifi Bastan F. Childhood trauma and the likelihood of increased suicidal risk in schizophrenia. Psychiatry Res 2019;275:100-107.
crossref pmid
13. Li XB, Bo QJ, Tian Q, Yang NB, Mao Z, Zheng W, et al. Impact of childhood trauma on sensory gating in patients with first-episode schizophrenia. BMC Psychiatry 2018;18:258
crossref pmid pmc pdf
14. Quidé Y, Ong XH, Mohnke S, Schnell K, Walter H, Carr VJ, et al. Childhood trauma-related alterations in brain function during a Theory-ofMind task in schizophrenia. Schizophr Res 2017;189:162-168.
crossref pmid
15. Sumner JA, Duncan L, Ratanatharathorn A, Roberts AL, Koenen KC. PTSD has shared polygenic contributions with bipolar disorder and schizophrenia in women. Psychol Med 2016;46:669-671.
crossref pmid
16. Priebe S, Bröker M, Gunkel S. Involuntary admission and posttraumatic stress disorder symptoms in schizophrenia patients. Compr Psychiatry 1998;39:220-224.
crossref pmid
17. Shaw K, McFarlane AC, Bookless C, Air T. The aetiology of postpsychotic posttraumatic stress disorder following a psychotic episode. J Trauma Stress 2002;15:39-47.
crossref pmid
18. Dunkley JE, Bates GW, Findlay BM. Understanding the trauma of first-episode psychosis. Early Interv Psychiatry 2015;9:211-220.
crossref pmid
19. Berry K, Ford S, Jellicoe-Jones L, Haddock G. PTSD symptoms associated with the experiences of psychosis and hospitalisation: a review of the literature. Clin Psychol Rev 2013;33:526-538.
crossref pmid
20. Buckley PF, Miller BJ, Lehrer DS, Castle DJ. Psychiatric comorbidities and schizophrenia. Schizophr Bull 2009;35:383-402.
crossref pmid
21. Achim AM, Maziade M, Raymond E, Olivier D, Mérette C, Roy MA. How prevalent are anxiety disorders in schizophrenia? A meta-analysis and critical review on a significant association. Schizophr Bull 2011;37:811-821.
crossref pmid pmc
22. Dallel S, Cancel A, Fakra E. Prevalence of posttraumatic stress disorder in schizophrenia spectrum disorders: a systematic review. Neuropsychiatry 2018;8:1027-1037.
23. Seow LSE, Ong C, Mahesh MV, Sagayadevan V, Shafie S, Chong SA, et al. A systematic review on comorbid post-traumatic stress disorder in schizophrenia. Schizophr Res 2016;176:441-451.
crossref pmid
24. Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, et al. Meta-analysis of observational studies in epidemiology: a proposal for reporting. JAMA 2000;283:2008-2012.
crossref pmid
25. Moher D, Liberati A, Tetzlaff J, Altman DG, PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg 2010;8:336-341.
crossref pmid
26. OConghaile A, DeLisi LE. Distinguishing schizophrenia from posttraumatic stress disorder with psychosis. Curr Opin Psychiatry 2015;28:249-255.
crossref pmid
27. Hoy D, Brooks P, Woolf A, Blyth F, March L, Bain C, et al. Assessing risk of bias in prevalence studies: modification of an existing tool and evidence of interrater agreement. J Clin Epidemiol 2012;65:934-939.
crossref pmid
28. Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ 2003;327:557-560.
crossref pmid pmc
29. Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ 1997;315:629-634.
crossref pmid pmc
30. Meyer H, Taiminen T, Vuori T, Aijälä A, Helenius H. Posttraumatic stress disorder symptoms related to psychosis and acute involuntary hospitalization in schizophrenic and delusional patients. J Nerv Ment Dis 1999;187:343-352.
crossref pmid
31. Mueser KT, Goodman LB, Trumbetta SL, Rosenberg SD, Osher fC, Vidaver R, et al. Trauma and posttraumatic stress disorder in severe mental illness. J Consult Clin Psychol 1998;66:493-499.
crossref pmid
32. Ng LC, Petruzzi LJ, Greene MC, Mueser KT, Borba CP, Henderson DC. Posttraumatic stress disorder symptoms and social and occupational functioning of people with schizophrenia. J Nerv Ment Dis 2016;204:590-598.
crossref pmid pmc
33. Strakowski SM, Keck PE Jr, McElroy SL, Lonczak HS, West SA. Chronology of comorbid and principal syndromes in first-episode psychosis. Compr Psychiatry 1995;36:106-112.
crossref pmid
34. Kessler RC, Birnbaum H, Demler O, Falloon IR, Gagnon E, Guyer M, et al. The prevalence and correlates of nonaffective psychosis in the National Comorbidity Survey Replication (NCS-R). Biol Psychiatry 2005;58:668-676.
crossref pmid pmc
35. Kendler KS, Gallagher TJ, Abelson JM, Kessler RC. Lifetime prevalence, demographic risk factors, and diagnostic validity of nonaffective psychosis as assessed in a US community sample. The national comorbidity survey. Arch Gen Psychiatry 1996;53:1022-1031.
36. Garvey M, Noyes R Jr, Anderson D, Cook B. Examination of comorbid anxiety in psychiatric inpatients. Compr Psychiatry 1991;32:277-282.
crossref pmid
37. Vogel M, Spitzer C, Barnow S, Freyberger HJ, Grabe HJ. The role of trauma and PTSD-related symptoms for dissociation and psychopathological distress in inpatients with schizophrenia. Psychopathology 2006;39:236-242.
crossref pmid pdf
38. Braga RJ, Mendlowicz MV, Marrocos RP, Figueira IL. Anxiety disorders in outpatients with schizophrenia: prevalence and impact on the subjective quality of life. J Psychiatr Res 2005;39:409-414.
crossref pmid
39. Ciapparelli A, Paggini R, Marazziti D, Carmassi C, Bianchi M, Taponecco C, et al. Comorbidity with axis I anxiety disorders in remitted psychotic patients 1 year after hospitalization. CNS Spectr 2007;12:913-919.
crossref pmid
40. Strakowski SM, Tohen M, Stoll AL, Faedda GL, Mayer PV, Kolbrener ML, et al. Comorbidity in psychosis at first hospitalization. Am J Psychiatry 1993;150:752-757.
crossref pmid
41. Seedat S, Fritelli V, Oosthuizen P, Emsley RA, Stein DJ. Measuring anxiety in patients with schizophrenia. J Nerv Ment Dis 2007;195:320-324.
crossref pmid
42. Karatzias T, Gumley A, Power K, O’Grady M. Illness appraisals and self-esteem as correlates of anxiety and affective comorbid disorders in schizophrenia. Compr Psychiatry 2007;48:371-375.
crossref pmid
43. Tibbo P, Swainson J, Chue P, LeMelledo JM. Prevalence and relationship to delusions and hallucinations of anxiety disorders in schizophrenia. Depress Anxiety 2003;17:65-72.
crossref pmid
44. Sim K, Chua TH, Chan YH, Mahendran R, Chong SA. Psychiatric comorbidity in first episode schizophrenia: a 2 year, longitudinal outcome study. J Psychiatr Res 2006;40:656-663.
crossref pmid
45. DeTore NR, Gottlieb JD, Mueser KT. Prevalence and correlates of PTSD in first episode psychosis: Findings from the RAISE-ETP study. Psychol Serv 2021;18:147-153.
crossref pmid
46. Halász I, Levy-Gigi E, Kelemen O, Benedek G, Kéri S. Neuropsychological functions and visual contrast sensitivity in schizophrenia: the potential impact of comorbid posttraumatic stress disorder (PTSD). Front Psychol 2013;4:136
crossref pmid pmc
47. Kiran C, Chaudhury S. Prevalence of comorbid anxiety disorders in schizophrenia. Ind Psychiatry J 2016;25:35-40.
crossref pmid pmc
48. Neria Y, Bromet EJ, Sievers S, Lavelle J, Fochtmann LJ. Trauma exposure and posttraumatic stress disorder in psychosis: findings from a first-admission cohort. J Consult Clin Psychol 2002;70:246-251.
crossref pmid
49. Newman JM, Turnbull A, Berman BA, Rodrigues S, Serper MR. Impact of traumatic and violent victimization experiences in individuals with schizophrenia and schizoaffective disorder. J Nerv Ment Dis 2010;198:708-714.
crossref pmid
50. Pallanti S, Quercioli L, Hollander E. Social anxiety in outpatients with schizophrenia: a relevant cause of disability. Am J Psychiatry 2004;161:53-58.
crossref pmid
51. Peleikis DE, Varga M, Sundet K, Lorentzen S, Agartz I, Andreassen OA. Schizophrenia patients with and without post-traumatic stress disorder (PTSD) have different mood symptom levels but same cognitive functioning. Acta Psychiatr Scand 2013;127:455-463.
crossref pmid
52. Resnick SG, Bond GR, Mueser KT. Trauma and posttraumatic stress disorder in people with schizophrenia. J Abnorm Psychol 2003;112:415-423.
crossref pmid
53. Sarkar J, Mezey G, Cohen A, Singh SP Olumoroti O. Comorbidity of post traumatic stress disorder and paranoid schizophrenia: a comparison of offender and non-offender patients. J Forens Psychiatry Psychol 2005;16:660-670.
54. Schäfer I, Eiroa-Orosa FJ, Schroeder T, Aderhold V. [Posttraumatic disorders in patients with schizophrenia spectrum disorders]. Nervenarzt 2015;86:818-825. German.
crossref pmid pdf
55. Steel C, Haddock G, Tarrier N, Picken A, Barrowclough C. Auditory hallucinations and posttraumatic stress disorder within schizophrenia and substance abuse. J Nerv Ment Dis 2011;199:709-711.
crossref pmid
56. Vogel M, Schatz D, Spitzer C, Kuwert P, Moller B, Freyberger HJ, et al. A more proximal impact of dissociation than of trauma and posttraumatic stress disorder on schneiderian symptoms in patients diagnosed with schizophrenia. Compr Psychiatry 2009;50:128-134.
crossref pmid
57. Sin GL, Abdin E, Lee J, Poon LY, Verma S, Chong SA. Prevalence of post-traumatic stress disorder in first-episode psychosis. Early Interv Psychiatry 2010;4:299-304.
crossref pmid
58. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM-IV). Washington, DC: American Psychiatric Association; 1994.

59. Weiss DS, Marmar CR. The impact of event scale: revised. In: Wilson JP, Keane TM, editor. Assessing psychological trauma and PTSD. New York: Guilford Press, 1996, p. 399-411.

60. Mollica RF, Caspi-Yavin Y, Bollini P, Truong T, Tor S, Lavelle J. The Harvard trauma questionnaire. Validating a cross-cultural instrument for measuring torture, trauma, and posttraumatic stress disorder in Indochinese refugees. J Nerv Ment Dis 1992;180:111-116.
61. Blake DD, Weathers FW, Nagy LM, Kaloupek DG, Gusman FD, Charney DS, et al. The development of a Clinician-Administered PTSD Scale. J Trauma Stress 1995;8:75-90.
crossref pmid
62. Watson CG, Juba MP, Manifold V, Kucala T, Anderson PE. The PTSD interview: rationale, description, reliability, and concurrent validity of a DSM-III-based technique. J Clin Psychol 1991;47:179-188.
crossref pmid
63. Picken A, Tarrier N. Trauma and comorbid posttraumatic stress disorder in individuals with schizophrenia and substance abuse. Compr Psychiatry 2011;52:490-497.
crossref pmid
64. Calhoun PS, Stechuchak KM, Strauss J, Bosworth HB, Marx CE, Butterfield MI. Interpersonal trauma, war zone exposure, and posttraumatic stress disorder among veterans with schizophrenia. Schizophr Res 2007;91:210-216.
crossref pmid
65. Patel AR, Hall BJ. Beyond the DSM-5 diagnoses: a cross-cultural approach to assessing trauma reactions. Focus (Am Psychiatr Publ) 2021;19:197-203.
crossref pmid pmc


Browse all articles >

Editorial Office
#522, 27, Seochojungang-ro 24-gil, Seocho-gu, Seoul 06601, Korea
Tel: +82-2-717-0892    E-mail:                

Copyright © 2023 by Korean Neuropsychiatric Association.

Developed in M2PI

Close layer
prev next