The lifetime prevalence of PTSD ranges from 5 to 10%, according to studies of PTSD conducted among the general population of the United States and Europe (1, 2), with women are more likely to develop PTSD than men (3). Serious mental illnesses (SMIs) are mental, behavioral, or emotional disorders that result in serious functional impairment, i.e., that affect an individual's ability to perform major life activities such as working, maintaining social relationships, or taking care of oneself (4) (the most common SMIs include, but are not limited to, schizophrenia, schizoaffective disorder, bipolar disorder, and major depression). Research supports that trauma and SMI are intertwined in two ways: (1) individuals can develop SMI after being exposed to trauma in their childhood (5, 6), and (2) individuals who develop SMI also have a higher risk of experiencing violent victimization (7). As a result, exposure to multiple traumas is nearly universal for individuals with SMI (8), and people with SMI have higher rates trauma exposure than individuals without SMI (9–12). Further, the prevalence of PTSD has been reported as 25–48% among people with SMI (9), almost ten times that of the general population (2). Research indicates that co-occurring PTSD can worsen the course of SMI, leading to more severe symptoms, (including psychosis, anxiety, and depression), psychosocial impairment, lower quality of life, poorer physical health and greater use of psychiatric and emergency services (13–15). In addition, studies have shown gender difference on cumulative impact of trauma on psychosis: childhood physical abuse was experienced more frequently by males with psychosis, while childhood sexual abuse and recent traumatic life experiences were more prevalent in females with psychosis (16). All together, SMI patients exposed to childhood trauma had poor clinical outcomes compared to those not exposed to childhood trauma, such as increased negative cognitions as well as dysfunctional metacognitive beliefs, and more severe psychiatric symptoms (16–19).

Consistent with findings among the general population (20), sudden death was reported to be the leading cause of PTSD in a study among persons with SMI (10) and was experienced by nearly 80% of the participants. The high frequency of sudden death of a loved one, including violent death in this sample of clients with SMI, and its association with PTSD, raises the question of the related syndrome of Prolonged Grief Disorder [PGD; (21)], which can follow the sudden, unexpected death of a loved one (22). PGD is marked by disabling separation, distress and grief-specific symptoms, such as yearning for the deceased, difficulties accepting the death, and difficulties moving on in life, that are distinct from both PTSD and depression (23, 24). Prevalence rates of PGD are estimated to range from 7 to 20% after a person experiences bereavement (24, 25). Persons with PGD are more likely to develop health complications, die by suicide, and be diagnosed with an affective or anxiety disorder (26, 27). As research indicates that the unexpected death of a loved one is the most commonly reported trauma among participants receiving public mental health treatment (10, 11), it is plausible that the combination of trauma and PGD may contribute to multi-morbidity for persons with SMI (28, 29). The notion of multi-morbidity, or two or more chronic conditions, is a relatively new conceptualization of medical complexity in medicine, including psychiatry, and is associated with increased disability, mortality, and decreased quality of life (28, 30). SMI clients with PTSD and PGD may present a subset of multi-morbidity, which may lead to increased disability (31).

Despite significant overlap between PTSD and PGD (32, 33), to date, there has been little research examining PTSD and PGD and associated outcomes among SMI clients. The aims of the present study were: (1) to assess the rates of both PTSD and PGD in one sample of SMI clients (Study 1); (2) to report on the clinical correlates of PTSD and PGD (Study 2). We hypothesized that, consistent with multi-morbidity theory (28, 30), SMI clients with PTSD and PGD would have worse symptoms and more impairment compared to those with PTSD only. Toward this end, the present study reports findings from a multi-site comprehensive screening of SMI clients (Study 1). We also report on the clinical and functional correlates of combined PTSD and PGD among a smaller sample of individuals found to meet criteria DSM-5 criteria for PTSD (Study 2).

Findings reported here were drawn from a larger randomized control trial (RCT) comparing a 12-week group cognitive behavioral treatment (CBT) for PTSD program with treatment as usual (TAU) in community mental health programs, serving clients with SMI, operated in three Northeastern states (Lu et al., unpublished¹). The study protocol, consent, and all study-related materials were reviewed and approved by the university Institutional Review Board. Study participants were people with SMI (schizophrenia, major depression, bipolar disorder, etc.) receiving vocational services at 10 community mental health programs. The study sites were located in urban, suburban and rural communities. Additionally, the community mental health programs were all part of larger mental health agencies that provided an array of services including; pharmacological treatment, psychological treatment, supportive housing, partial care, medication management, counseling, peer support, assertive community treatment, and other case management programs. In order to facilitate referrals for the RCT (Study 2), trauma history and PTSD screening were implemented at these sites (Study 1). Participants who were screened for PTSD for the RCT comprised Study 1. Study 2 consisted of those who met criteria for PTSD and were enrolled in the RCT.

In study 1, program and study staff were trained to conduct PTSD and PGD screening and coordinated to choose dates for screenings at their respective programs. Staff then notified the program clients of the opportunity to be screened for PTSD, and the dates the study staff would conduct the screenings at the agency. Agency staff posted flyers in the office as well as made personal calls to clients informing them of the day of the screening (note that the invitation to participate was open to all clients at the recruitment sites). Individuals who were interested came to the program on the day of the screening and met with study personnel who explained the screening process. If the individual agreed, study personnel and staff conducted a comprehensive screening of trauma exposure and PTSD and PGD symptoms. Participants first completed a trauma screening measure, and if they indicated “yes” on sudden death of a loved one were asked to complete PGD measure. Participants who agreed then completed a permission to contact form, Authorization of Release of Protected Health Information form, and a consent form to have the results of the screening provided to the research team. Additionally, an eligibility checklist was filled out by participants who included self-reported diagnoses. Sex was recorded as noted by the interviewers. Participants were paid $10 for completing the screening.

Upon completion of the trauma screening in Study 1, participants were then asked if they were willing to have their screening data provided to the research team for possible participation in a treatment study of CBT for PTSD (Study 2). Participants indicated whether they would be interested in being contacted by the research team if they met preliminary eligibility criteria for the study. For Study 2, inclusion criteria were the following: (1) age ≥ 18; (2) currently receiving SE services within the past 24 months; (3) history of treatment for mental illness; (4) current diagnosis of PTSD; (5) no current diagnosis of alcohol or drug dependence as described in chart; (6) no hospitalization or suicide attempt in the past 2 months; and (7) willingness to provide informed consent to participate in the study. Potentially eligible and interested clients were contacted by a team member, who described the study and obtained informed consent. Once consent was obtained, the completion of a baseline interview would confirm the eligibility of participation. Participants were paid $30 for the completion of the baseline interview.

This is the first study, to our knowledge, to examine the rates and correlates of PTSD and probable PGD among SMI clients. The findings are generally consistent with previous findings in indicating that trauma exposure is highly prevalent among persons with SMIs (9). Compared to other studies that used the TLEQ to assess trauma exposure in different populations (10, 39, 44), participants in the current study had higher rates of witnessing family violence and childhood sexual abuse but similar or lower levels of exposure to other types of traumatic events listed on TLEQ compared to 129 clients receiving opioid dependence treatment. Participants in this study reported higher rates of domestic violence, adult sexual assault, and childhood sexual abuse but reported lower rates of exposure to other types of trauma such as warfare and stranger assault compared to 207 male military veterans self-identified as having PTSD (39). In addition, the direction of sex differences on trauma exposure is consistent with those found in the general population and in the population of persons with SMIs (10, 45). Participants in this study reported lower rates of trauma exposure to each category of trauma listed on TLEQ compared to CMHC clients pre-selected for probable PTSD in Lu et al. (10). The finding is consistent with the fact that this study utilized trauma screening applied to all interested participants receiving vocational services at CMHCs, and did not preselect those with PTSD. The total trauma exposure reported in this study was around six types of trauma events which was significantly lower than seven types among CMHC participants preselected with probable PTSD in Lu et al. (10), and nine types among military veterans with self-identified PTSD described by Weathers et al. (39). Also, time interval since the most distressing trauma was approximately 18 years ago, similar to that of CMHC participants with probable PTSD described by Lu et al. (10), indicating that the most distressing event typically happened early on in life.

Regarding the relationship between PTSD and PGD, we found that nearly half of participants met criteria for PTSD, while roughly 15% met criteria for probable PGD, whereas, roughly 12% met the criteria for both PTSD and probable PGD. Further, having probable PGD increased the odds of having PTSD by nearly 5 times. The combination of PTSD and probable PGD also appeared to have a clinical impact, as participants who met criteria for PTSD and probable PGD had higher PTSD symptom severity. This is consistent with previous findings among veterans with combat-related PTSD that those with PGD had greater severity of PTSD (46). SMI clients who have experienced grief and loss may experience particular challenges that may require additional support. O'Hare and Sherrer (47) suggest that clients with SMIs may benefit from grief counseling; research is needed for such an intervention for this population. Clients with both PTSD and PGD present as a group with a higher service need, which is consistent with the conceptualization of multimorbidity in recent literature (28, 29). While there are some evidence-based practices for PGD (48, 49), there has not been efficacy studies on treatment of traumatic loss (50), future efficacy studies are needed which integrate both PTSD and grief treatment interventions to provide trauma-informed services for SMI clients among whom, multi-morbidity is common. The finding that being African American was associated with increased likelihood of having both PTSD and probable PGD is consistent with the social and cultural determinants of traumatic loss/grief (51), in which determinants such as cultural, social factors related to loss may facilitate or complicate the grieving process and therefore call for culturally sensitive care for traumatic grief.

Some limitations of the present study should be noted. Diagnoses of PTSD in Study 1 were based on self-report and therefore may be less reliable than research-based diagnoses conducted using CAPS-5. Furthermore, the last item in PG-13 was omitted, lending less certainty to the reliability of the diagnosis of PGD. Research has indicated that using a measure such as Inventory of Complicated Grief (52) may result in a higher percentage of people meeting criteria for PGD than using PG-13 (53, 54). In study 1, diagnoses of PTSD and PGD were based on self-report. PGD was only assessed in participants indicating “sudden loss of a loved one”, thus participants with PGD following non-sudden death of a loved one were not assessed for PGD, possibly leading to under-estimation of PGD. Furthermore, because TLEQ data were collected in a dichotomous format, while it provided a sense of the range of exposure to different types of trauma which participants experienced, the number of traumatic experiences which participants had was undetermined (e.g., repeated experience of multiple traumatic events of the same type), thus precluding analysis of dose-response relationships between trauma load and PTSD severity. Moreover, the TLEQ did not distinguish sudden death from violent or accidental death. Therefore, those who reported their most distressing event as sudden death of loved ones might not have qualified for a criterion A event under the DSM-5, thus enabling a probable PTSD diagnosis made following sudden, non-violent death. Additionally, it is plausible that participants self-selected into the study possibly based on prior trauma, leading to an overestimate of the rate of trauma related disorders.

Future research needs to be conducted to more accurately assess the relationship between psychiatric symptoms and clinical outcomes for SMI clients with both PTSD and PGD. Future studies need to specify the types of sudden death as accidental or violent in the TLEQ. Further, participants were limited to those receiving vocational services at the community mental health agencies, therefore findings may not be generalizable to all SMI clients. A 2014 survey of mental health facilities serving clients with SMI reported that vocational services were offered at 20% of community mental health facilities in the US (55). PTSD and PGD therefore needs to be examined in a variety of clinical programs serving clients with SMI. In particular, PGD is now proposed for inclusion in DSM 5-TR which opens the door to new understandings of how trauma and loss collectively influence the course of SMI. As our findings suggest, many individuals living with the multi-morbidity of SMI, PTSD and PGD would benefit from specialized intervention.

The datasets presented in this article are not readily available because at the time of data collection (2014–2018), the informed consent did not include languages to allow participants to consent to having the data deposited to a data repository, so unfortunately, we will not be able to make the dataset available to the public. However after 2018, the funding agency NIDILRR has made a requirement for all funding projects to include languages in the consent form to allow the possibility of having the data made publicly available through data repository mechanisms. Requests to access the datasets should be directed to Weili Lu, luwe1@shp.rutgers.edu.

The studies involving human participants were reviewed and approved by Newark Health Sciences Institutional Review Board. The patients/participants provided their written informed consent to participate in this study.

WL was the PI for this project, designed the project, supervised the operation of the project and data collection, data entry, data analysis, and contributed to the conception and the writing of the manuscript. PY was the co-investigator of the project, supervised the project, and contributed to the conceptualization and writing. WW was the co-PI for the project, supervised the project, and contributed to the writing. CG and CB contributed to the data collection and data analysis. GG was the coinvestigator of the project, supervised data collection, and also did data entry. KG was the co-investigator and contributed to data analysis and writing. DB contributed to data cleaning, data analysis, editorial assistance, and the composition of the tables. HP provided study instruments for PGD and contributed to conceptualization and writing. All authors contributed to the article and approved the submitted version.

This research was funded by National Institute on Disability, Independent Living, and Rehabilitation Research [NIDILRR Grant #90IF0074 (formerly H133G140147)].

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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