Victims with Posttraumatic Stress Disorder: a Randomized
Control Trial
Résumé
Les victimes d’agression sexuelle (VAS) sont particulièrement à risque de développer un état de stress post-traumatique (ÉSPT) et la thérapie cognitive-comportementale (TCC) centrée sur le trauma est un traitement bien appuyé par la littérature pour le traitement de cette pathologie. Cependant, elle ne cible pas directement les difficultés de sommeil, incluant les cauchemars, bien que celles-ci fassent partie intégrante du tableau clinique de l’ÉSPT. Comme les cauchemars sont particulièrement répandus chez les VAS et que les difficultés de sommeil associées à l’ÉSPT ont des conséquences importantes sur la santé, le fonctionnement et la qualité de vie, ces difficultés paraissent agir à titre de facteur de maintien des symptômes post-traumatiques. Le présent article évalue l’efficacité d’un traitement des cauchemars (par la Révision et répétition par imagerie mentale; RRIM) et d’une TCC de l’ÉSPT offerts de manière séquentielle, en comparaison à une TCC seule. Quarante-deux VAS souffrant d’un ÉSPT et de difficultés de sommeil ont été recrutées et assignées aléatoirement à l’une ou l’autre des deux conditions de traitement (RRIM+TCC ou période d’attente suivie d’une TCC seule). Une entrevue clinique, de même qu’une série de questionnaires évaluant les symptômes post-traumatiques, le fonctionnement et la qualité de vie leur ont été administrées. Les résultats supportent la supériorité de la RRIM pour traiter les symptômes post-traumatiques nocturnes des VAS, en comparaison à une période d’attente (p < .05 pour tous les effets d’interaction associés aux variables du sommeil). Les deux groupes ont montré des améliorations subséquentes de leurs symptômes post-traumatiques nocturnes (sauf la fréquence des cauchemars) et diurnes, de leur fonctionnement général et de leur santé mentale pendant la TCC (tous les p < .05). Malgré des différences de taille modérée à modérée-élevée (d de Cohen variant entre 0.45 et 0.63) observées au post-traitement entre les groupes quant aux variables du sommeil, aucune différence significative n’a été détectée. Chez les participants qui ont complété leur thérapie, des taux plus importants d’améliorations cliniquement significatives au plan du sommeil ont été notés entre le premier et le dernier temps de mesure pour les participants du groupe expérimental. Bref, bien que la supériorité de la combinaison RRIM+TCC n’ait pu être clairement établie, ces résultats paraissent prometteurs et soulèvent la possibilité d’optimiser les gains observés face au sommeil, en intégrant des stratégies les ciblant directement dans les protocoles standard de traitement de l’ÉSPT.
Abstract
Sexual assault victims (SAV) have an elevated risk of developing posttraumatic stress disorder (PTSD). Trauma-focused cognitive-behavioural therapy (CBT) is an effective treatment for this pathology. However, although sleep disturbances are a common complaint in SAV with PTSD, trauma-focused CBT does not directly address this symptom. Posttraumatic nightmares are widespread among SAV. Trauma-related sleep disturbances are associated with significant impairment in general functioning and quality of life (mental and physical health), and contribute to the maintenance of PTSD symptoms. This study evaluates the efficacy of sequential nightmare therapy (imagery rehearsal therapy; IRT) and trauma-focused CBT, in comparison to CBT alone. Forty-two SAV suffering from PTSD and sleep difficulties were recruited and randomly assigned to the experimental (IRT+CBT) or control condition (waiting period followed by CBT alone). Participants were administered a clinical interview and a series of questionnaires assessing PTSD symptoms, general functioning and quality of life. The results demonstrated that IRT yielded greater improvement in nocturnal PTSD symptoms than did the waiting period (p < .05 for all interaction effects). Both groups subsequently demonstrated significant decreases in nocturnal (except for nightmare frequency) and diurnal PTSD symptoms, as well as improvements in general functioning and mental health (p < .05). Although medium to medium-large differences between the control group and experimental group were observed on nocturnal symptoms at post-treatment (Cohen’s d from 0.45 to 0.63), the two groups did not differ significantly. Among treatment completers, participants in the experimental group demonstrated greater clinically significant improvement between initial and final assessment than did participants in the control group. Although the results of this study did not clearly establish the superiority of IRT+CBT over CBT alone, the findings are promising and imply that integrating sleep therapy strategies into traditional PTSD treatment protocols may optimize treatment outcomes.
Introduction
The prevalence of sexual assault ranges from 14% to 25% in adult women and from 0.6% to 7% in adult men (Elliott, Mok, & Briere, 2004; Koss, 1993; Tjaden & Thoennes, 2000). The prevalence rates for sexual assault prior to age 18 are higher; 12% to 35% of women and 4% to 9% of men report experiencing sexual assault as a minor (Molnar, Buka, & Kessler, 2001; Putnam, 2003). Sexual assault victims (SAV) are at an elevated risk for developing mental health problems such as anxiety (fear for personal safety, fear of the perpetrator of sexual assault, disclosure anxiety); depressive symptoms (sadness about the sexual assault, suicidal thoughts, low self-esteem, major depressive episode); paranoid ideation; personality problems (primarily borderline personality disorder); sexual difficulties; and impaired general functioning (Koss, Goodman, Browne, Fitzgerals, Keita, & Russo,1994; Maniglio, 2009; Peterson, Voller, Polusny, & Murdoch, 2011; Romano & Luca, 2001). Posttraumatic symptoms are a common complaint among SAV. Posttraumatic stress disorder (PTSD) frequently develops immediately after the assault, or months or even years later (Hornor, 2010).
The DSM-IV criteria for PTSD includes intrusion symptoms (recurrent, involuntary, and intrusive distressing memories; nightmares; flashbacks); avoidance symptoms (of thoughts, conversations and situations associated with trauma); numbing (restricted affect, detachment); and hyperarousal symptoms (hypervigilance, insomnia, exaggerated startle response) following exposure to trauma (APA, 2000). The following criteria were added in DSM-5: negative alteration in cognitions (distorted cognitions about the cause and consequences of the traumatic event) and in mood (persistent negative emotional state and decreased interest in activity) (APA, 2013).
Trauma-exposed individuals with PTSD often report sleep disturbances. Up to 70% to 87% of this population experience sleep difficulties. This figure represents a 48% to 60% greater risk for sleep problems than that observed in the general population (Maher, Rego, & Asnis, 2006). In individuals exposed to trauma, nightmares and insomnia are respectively conceptualized as intrusion and hyperarousal symptoms (APA, 2013). This common conceptualization implies that trauma-related sleep disturbances are secondary to
PTSD. However, recent findings call this classification into question and suggest that sleep disturbances may be a core feature of PTSD. Nightmares and insomnia symptoms in the aftermath of a traumatic event have been demonstrated to predict the subsequent development of PTSD (Koren, Arnon, Lavie, & Klein, 2002; Mellman, David, Bustamante, Torres, & Fins, 2001). Moreover, sleep disturbances perpetuate PTSD by exacerbating diurnal posttraumatic symptoms such as difficulty concentrating, irritability, agitation and impaired emotion regulation (Spoormaker & Montgomery, 2008).
Of all traumatic experiences, sexual assault is the type of trauma associated with the highest rate of PTSD diagnoses (Breslau et al., 1998; Hapke et al., 2006; Kessler, Sonnega, & Bromet, 1995). SAV generally report greater PTSD symptom severity and more general distress than do victims of other types of trauma (Chung & Breslau, 2008; Shakespeare- Finch & Armstrong, 2010). SAV also experience particularly frequent nightmares and insomnia symptoms (difficulty falling or staying asleep), and suffer from overall poor sleep quality (poor subjective sleep quality, longer sleep latency, shorter sleep duration, poor sleep efficiency, sleep disturbances, use of sleeping medication and daytime dysfunctions) (Duke, Allen, Rozee, & Bommaritto, 2008; Krakow et al., 2001; Krakow et al., 2002a).
According to expert consensus guidelines, trauma-focused CBT is the psychological treatment of choice for PTSD (Bisson & Andrew, 2007; Foa, Davidson, & Frances, 1999). Trauma-focused CBT is associated with significant decreases in posttraumatic symptoms, and improved quality of life and general functioning (Agency for Healthcare Research and Quality, 2013; Powers, Halpern, Ferenschak, Gillihan, & Foa, 2010). Its efficacy has been validated in sexual assault victims (Cusack et al., 2016; Ehring, Welboren, Morina, Wicherts, Freitag, & Emmelkamp, 2014), with clinical improvement maintained over time (six-year follow-up) (Resick, Williams, Suvak, & Monson, 2012). However, the vast majority of patients who receive CBT or other effective treatment for PTSD report lingering sleep difficulties post-therapy (Belleville, Guay, & Marchand, 2011; Galovski et al., 2009; Zayfert & DeViva, 2004). This finding suggests that trauma-related sleep disturbances should be directly addressed via strategies such as Imagery Rehearsal Therapy (IRT).
IRT is currently the treatment of choice for nightmares (Aurora et al., 2010). This cognitive-behavioural approach is designed to alter the conditioned association between nightmares and sleep via rehearsal of a modified dream script in daytime. Results of a recent meta-analysis indicate that IRT has a medium effect on nightmare frequency, a large effect on overall PTSD symptoms and a small effect on sleep quality (Casement & Swanson, 2012). To our knowledge, no study to date has combined IRT and trauma- focused CBT for PTSD. IRT and trauma-focused CBT are both associated with decreases in diurnal PTSD symptoms, and IRT directly and effectively treats PTSD sleep complaints.
Objective and hypothesis
The objective of this study was to evaluate the efficacy of treatment for nightmares (IRT) followed by treatment for PTSD (CBT for PTSD) for nocturnal and diurnal PTSD symptoms, general functioning and quality of life. The first hypothesis was that sequential treatment (IRT+CBT) would yield greater decreases in nightmare frequency, nightmare distress, sleep quality and disruptive nocturnal behaviours than would CBT alone. The second hypothesis was that IRT+CBT would yield greater decreases in daytime PTSD symptoms, general functioning and quality of life than would CBT alone.
Method
Participants
Sexual assault victims seeking treatment in the Quebec City (Canada) area were recruited via email announcements to Laval University students, advertisements in college campuses and referrals from rape crisis centres and mental health organizations. Inclusion criteria were: (a) over 18 years of age; (b) able to understand and speak French; (c) history of unwanted sexual experience; (d) PTSD diagnosis according to DSM-IV-TR; (e) sleep complaints, as established by Pittsburgh Sleep Quality Index score ≥ 5 and a mean of one or more NM per week for at least one month; (f) if psychotropic medication was used, (antidepressant, antianxiety, antipsychotic or hypnotic medication) stable for a minimum of three months; and (g) available for in-person assessments and therapy sessions. Exceptions were made for two participants who scored under 5 on the Pittsburgh Sleep Quality Index
but reported clinically significant sleep difficulties during the clinical interview, i.e. frequent NM, NM distress and DNB. Exceptions were also made for four participants who reported fewer than one NM/week in the past month at the time of the clinical interview, but claimed that their usual frequency was greater. The latter participants also reported clinically significant sleep difficulties including NM distress, poor sleep quality and DNB. Exclusion criteria included: (a) past or present psychotic episode, bipolar disorder or organic mental disorder (e.g. dementia); (b) substance use disorder; (c) sleep apnea diagnosis; (d) use of prazosin to treat nightmares; (e) presently in treatment for psychological difficulties; and (f) significant suicidal thoughts requiring immediate intervention.
A total of 123 telephone screening interviews were conducted; 53 individuals appeared to be eligible and were invited for a clinical assessment. Following clinical assessment, 42 participants were included in the study. Figure 1 illustrates the recruitment flowchart. With the exception of two additional participants excluded due to suicidal thoughts that required immediate intervention, we used the same sample used in a separate study that explored characteristics of traumatic assault as predictors of nocturnal and diurnal PTSD symptoms in SAV (Dubé-Frenette & Belleville, 2016).
Measures
Participants were administered the Clinician-Administered PTSD Scale (CAPS; Blake et al., 1995) to assess PTSD diagnosis. The Structured Clinical Interview for DSM-
IV Axis I disorders (SCID-IV; First, Spitzer, Gibbon, & Williams, 1996) was used to assess
axis I comorbidity. Primary measures were used to assess nocturnal PTSD symptoms. Secondary measures were used to assess diurnal PTSD symptoms, general functioning and quality of life.
The Nightmare Distress Questionnaire (NDQ; Belicki, 1992a) was used to assess nightmare distress and frequency. This questionnaire includes 13 items that assess waking distress associated with NM and interest in NM therapy. Total score ranges from 0 to 52; higher scores indicate greater distress. For the purpose of the study, total score was
calculated without the two questions assessing interest in therapy. The original NDQ has good psychometric properties, but no validated French version exists. A non-validated translation was used, with added questions assessing NM frequency (number of NM per month and number of nights per month with NM).
The Pittsburgh Sleep Quality Index (PSQI; Buysse, Reynolds, Monk, Berman, & Kupfer, 1989) was used to assess overall sleep quality (sleep latency, sleep duration, sleep disturbances, impairments in daytime functioning, subjective sleep quality, sleep efficiency and use of sleep medication). This questionnaire includes 19 items; total score ranges from 0 to 21 (clinical cut-off score of 5), with higher scores indicating poorer sleep quality. The French version of the PSQI has satisfactory psychometric properties (Blais, Gendron, Mimeault, & Morin, 1997).
The Pittsburgh Sleep Quality Index – Addendum for PTSD (PSQI-A; Germain, Hall, Krakow, Shear, & Buysse, 2005) was used to assess the frequency of DNB associated with PTSD (hot flashes, general nervousness, memories or NM of traumatic experience, severe anxiety or panic not related to traumatic memories, bad dreams not related to traumatic memories, episodes of terror or screaming during sleep without fully awakening and episodes of acting out dreams). The questionnaire includes 7 items; total score ranges from 0 to 21 (clinical cut-off score of 4), with higher scores indicating more frequent difficulties. A validated French version of the PSQI-A was used (Ait-Aoudia et al., 2013).
The Modified PTSD Symptom Scale – Self Report (MPSS – SR; Falsetti, Resnick, Resick, & Kilpatrick, 1993) was used to assess severity and frequency of daytime PTSD symptoms. This questionnaire includes 17 items that reflect DSM-IV-TR criteria for PTSD. Total score ranges from 0 to 119, with higher scores indicating more frequent and severe symptoms. For the purpose of this study, total scores excluded the two sleep-related items (recurrent distressing dreams and difficulty falling or staying asleep) in order to measure daytime symptoms exclusively and avoid overlap with other sleep measures. The French version of the MPSS has been demonstrated to have good psychometric properties (Guay, Marchand, Iucci, & Martin, 2002).
The World Health Organization Disability Assessment Schedule (WHODAS; World Health Organization, 2001) was used to assess impairment in functioning. This questionnaire evaluates six domains of functioning (cognition, mobility, self-care, getting along, life activities and community participation). Total score ranges from 0 to 100, with higher scores indicating greater difficulties. This study used the French version of the WHODAS (World Health Organization, 2001).
The Medical Outcomes Study Health Survey (SF-36; Ware & Sherbourne, 1992) was used to assess quality of life. This questionnaire evaluates eight components of health (physical functioning, role limitations due to physical problems, social functioning, body pain, general mental health, role limitations due to emotional problems, vitality and general perceptions about health). The SF-36 yields two total scores (physical health and mental health), both of which were used in the current study. Total scores were calculated using Canadian norms (M = 50, SD = 10); higher scores indicated better functioning. The French version of the SF-36 has been demonstrated to have good psychometric properties (Dauphinee, Gauthier, Gandek, Magnan, & Pierre, 1997).
Procedures
At intake, participants were administered the CAPS to assess PTSD diagnosis and the SCID-IV to assess axis I comorbidity. Participants were also asked to complete self- report questionnaires assessing daytime and nighttime posttraumatic symptoms, general functioning and quality of life. Eligible participants were randomly assigned to the experimental condition (IRT+CBT sequential treatment) or to the control condition (CBT). Randomization was done with a random number generator. Participants in the experimental group received five sessions of IRT while participants in the control group began with a five-week waiting period. The waiting period included weekly telephone calls (average duration of 5 minutes) to provide psychological support (active listening and emotional validation) and monitor suicidal thoughts as needed. A second assessment was conducted five weeks after intake, and involved completion of the questionnaire battery for a second time. Following the second assessment, all participants received 15 sessions of trauma- focused CBT. The final assessment was conducted 15 weeks after the second assessment,
and included administration of the CAPS and a third completion of the self-report questionnaires. The Laval University ethics committee accepted the study protocol. Each participant signed a consent form and consented to be videotaped (for clinical supervision and evaluation of treatment integrity).
Treatments
We used the IRT protocol published by Nappi and collaborators (2010). The protocol includes five weekly 60-minute sessions. The first session was dedicated to psychoeducation about sleep, nightmares, mental imagery and the rationale for IRT. The second session included an introduction to pleasant imagery and the third session involved an introduction to targeted nightmare rescripting. The fourth session involved a review of the rescripted dream scenario and the final session was dedicated to relapse prevention. Participants were invited to practice imagery rehearsal of the new dream between sessions.
For the CBT treatment, we used the trauma-focused CBT protocol elaborated by Marchand and Guay from the Trauma Studies Centre (Institut universitaire en santé mentale de Montréal). Adapted from Foa, Hembree and Rothbaum (2007), the protocol includes 15 weekly 60- to 90-minute sessions. The first session was dedicated to establishing the therapeutic relationship and to a review of the results of the clinical assessment. Sessions 2 and 3 involved psychoeducation about PTSD symptoms and diaphragmatic breathing. Sessions 4 to 9 were dedicated to exposure to traumatic memories via imagery. Sessions 10 to 14 involved in vivo exposure to feared objects, activities and situations. The final session was dedicated to relapse prevention.
Quality control
To ensure the validity of the clinical assessments, initial interviews were administered by trained graduate students supervised by a licensed clinical psychologist specialized in PTSD. Post-treatment assessments were conducted by an independent evaluator who was not involved with the initial assessment or with treatment. Manualized treatment was provided by supervised graduate students. Participants were offered a version of the manual adapted for non-clinicians. All therapy sessions were filmed, and
independent judges (i.e., individuals not involved in administering clinical assessments or treatment) reviewed a randomly selected 25% of the videos of completed treatments (n = 8; 4 experimental treatments and 4 control treatments) to evaluate treatment integrity. Treatment integrity was rated using charts listing therapeutic strategies meant to be included/not included during PTSD and IRT sessions, respectively. The evaluation revealed that no elements of IRT were presented in the control condition, and that all of the appropriate strategies were presented in each condition.
Data analyses
Exploratory analyses were performed to assess assumptions and identify outliers. The assumption of normal distribution was met by transformation of problematic variables (NM frequency scores, WHODAS scores and physical health dimension scores). We used the two-step approach introduced by Templeton (2011): original variables were transformed to achieve uniformity (by calculating the percentile rank of each score) and subsequently transformed from uniformity to normality (using the inverse normal distribution function). No outliers were identified. Given the extremely strong correlations observed between NM per week and nights with NM per week at all measurement points (r = .841; r = .884; and r = .947; all p < .001), only the latter variable was selected for further analyses because its boundary characteristic (0 – 7 nights) limited the range of the scores.
Mixed model analyses of variance (ANOVA) with a factorial randomized experimental design (two treatment conditions X three assessment points) were performed to investigate whether or not there were significant differences in outcome between the two treatment conditions on daytime and nighttime PTSD symptoms, general functioning and quality of life. For a discussion of the advantages of mixed model analyses in repeated measures designs with missing data, see Keselman, Algina, and Kowalchuk (2001). Treatment condition (IRT+CBT vs CBT only) was entered as a fixed effect, measurement point (intake, second and final assessments) was entered as a repeated fixed effect and participants (43) were entered as a random effect. An unstructured variance-covariance matrix was selected. When the effect of time was significant, we calculated a priori
contrasts between means for intake and second assessment (IRT treatment for experimental group, waiting period for control group) and between means for second assessment and final assessment (CBT for both groups). Time effects were considered significant if alpha was inferior to 0.05. When the Group X Time interaction was significant, contrast analyses were performed as simple effects for each group. Between-group contrasts were performed at final assessment. Given the comparison of efficacy between two active treatments