DSM-5 Trauma and Stress-Related Disorders: Implications for Screening for Cancer-Related Stress

DSM-5: TrauMa anD STreSS-relaTeD DiSorDerS In DSM‐5, disorders which are precipitated by specific stressful and potentially trau‐ matic events are included in a new diag‐ nostic category, “Trauma and Stress‐Related Disorders,” which includes both Adjustment Disorders (ADs) and PTSD (5). Friedman and his colleagues (6) assert that there is heuristic value in grouping this set of dis‐ orders in a specific stress‐related category as it enables clinicians to differentiate between normal (non‐pathological) distress, from acute, diffuse clinically elevated stress reactions indicative of AD, to more severe and chronic psychopathology (including PTSD). This heuristic framework also has potential utility for delineating psychologi‐ cal disturbances arising from cancer‐related stress. It brings to the forefront the impor‐ tance of carefully differentiating whether a patient’s stress reactions pertaining to their cancer experience are acute, yet interfering with functioning, indicative of AD, or more severe psychopathology such as PTSD. Although ADs have been documented to be highly prevalent in cancer patients rang‐ ing up to 35% (7, 8), they have tended to be overlooked in studies specifically investi‐ gating the prevalence and characteristics of ca‐PTSD. Since the publication of DSM‐IV, from the studies which have examined the incidence or prevalence of ca‐PTSD utiliz‐ ing clinical diagnostic interviews, only a handful have differentially evaluated the occurrence of partial/sub‐threshold PTSD symptoms relative to AD or other anxiety or mood disorders [e.g., Ref. (9–11)]. From this small cohort of studies, the prevalence inTroDucTion It is well documented that being diagnosed and treated for cancer is understandably, a challenging experience associated with heightened distress. To this end, in 2009, the International Psycho‐Oncology Society endorsed distress as the sixth vital sign in cancer care (1). Indeed, cancer‐related dis‐ tress is common at pivotal periods in the prototypical trajectory of a cancer patients’ experience (including the diagnostic, treat‐ ment, recovery, and recurrence phases); and ranges on a continuum from normal, acute responses which may comprise ini‐ tial fear post‐diagnosis, to more severe, potentially chronic stress reactions that adversely impact functionality and general well‐being. Therefore, in the Fourth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV), being diag‐ nosed with a life‐threatening illness such as cancer was included for the first time as a potential traumatic event that could induce posttraumatic stress disorder (PTSD) (2). Since 1994, there has been a proliferation of studies investigating the prevalence and characteristics of cancer‐related PTSD (ca‐ PTSD) [see reviews, (3, 4)]. The majority of research has been based on self‐report questionnaires which has tended to inflate the rates of ca‐PTSD (with prevalence rates as high as 55%) compared to studies that have used the gold‐standard assessment method of structured, clinical diagnostic interviews (4). In fact, the prevalence rate for ca‐PTSD has been documented to be considerably lower when utilizing the lat‐ ter approach, ranging from 0 to 22% (3). With the Fifth Edition of DSM [DSM‐5; (5)], there are some notable changes to screening for stress‐related disorders and which have important implications for screening cancer patients and survivors. The purpose of this paper is to evaluate of ca‐PTSD compared to AD has been quite variable. Whereas some studies have found a much higher prevalence of AD relative to ca‐PTSD [e.g., 20 vs. 2% (11); 7 vs. 2% (12)], other studies have found ca‐PTSD is more prevalent than AD [e.g., 5 vs. 2% (13)]. These mixed outcomes may in part be due to differences in the timing of the assessment (i.e., time elapsed since cancer diagnosis and treatment completion), as well as in diagnostic approaches utilized to screen for ca‐PTSD relative to AD and other types of anxiety and mood disorders. A close inspection of the ca‐PTSD lit‐ erature indicates that a greater proportion of patients meet sub‐threshold symptoms for PTSD rather than full diagnostic cri‐ teria [e.g., 33 vs. 5% full‐PTSD (14); 13.6 vs. 0% full‐PTSD (15); 20.3 vs. 16.2% full‐ PTSD (16)]. In accordance with DSM‐IV (2) and DSM‐5 criteria (5), an AD diagno‐ sis should be considered for persons who only meet partial criteria for PTSD, and if these symptoms are not better accounted by another type of anxiety or depressive disor‐ der. However, the majority of cancer studies which have assessed PTSD symptoms, have not considered whether AD, or even another anxiety or mood disorder may better repre‐ sent the symptom profile for at least some cancer patients who elicit persistent distress for more than one month. To this end, the changes to some core criteria for PTSD in DSM‐5 will necessitate a more differential approach to assessing the symptom profile of stress reactions in cancer patients.