The effects of trauma on cognitive behaviour therapy for depression and alcohol misuse

Research Doctorate - Doctor of Philosophy (PhD)Posttraumatic stress disorder (PTSD) has been found to commonly co-occur with depression and alcohol use problems (including alcohol use disorders). PTSD when present with depression and/or alcohol use problems has also been found to exacerbate the comorbid symptoms. Despite the high comorbidity with (and the impact of) PTSD on depression and alcohol use problems, people presenting to services for treatment for depression and/or alcohol use tend not to be screened or treated for PTSD. Therefore, it is unknown what the effects of having PTSD on CBT treatment for depression and/or alcohol use problems are. Therefore, this thesis identifies and discusses prevalence rates of trauma exposure and PTSD in community and treatment seeking populations for depression and alcohol misuse. The impact of experiencing different traumatic event types on posttraumatic stress symptoms (PTSS), depression, and alcohol misuse are also explored. The effects of also having PTSD and/or experiencing particular traumatic event types on cognitive behaviour therapy (CBT) for depression and/or alcohol use disorders (AUD) is further explored. Finally, assessment and treatment recommendations (that are based on the findings of this thesis) for PTSD comorbidity in non-PTSD treatment settings, are proposed. Chapter 1 provides a literature review on the prevalence of traumatic event exposure, and rates of PTSD, major depressive disorder (MDD), and AUD in community and clinical populations. Diagnostic criteria for PTSD, depression, and AUD are reviewed, along with models of how these disorders develop and are maintained. The issue of PTSD comorbidity is discussed, with a focus on the current comorbidity perspective to expand from a dual diagnosis (i.e., PTSD-MDD and PTSD-AUD) to a multiple comorbidity framework (such as PTSD-MDD-AUD). CBT therapies are identified as an evidence-based treatment for PTSD, depression, and substance/alcohol use as a single disorder. Emerging research into integrated treatments for the dual disorders of PTSD-MDD, PTSD AUD, and MDD-AUD are also reviewed. The issue of the possible effects of a three-way comorbidity of PTSD-MDD-AUD is raised as there is no available research on the effects of having PTSD when seeking CBT treatment for depression and alcohol misuse. Chapter 2 has been published in a peer reviewed paper (Bailey, Webster, Baker, & Kavanagh, 2012) and explores traumatic exposure (including dysfunctional parenting), PTSS severity and PTSD in people seeking treatment for co-existing depressive symptoms and alcohol misuse problems. We found that trauma experiences and PTSD are highly prevalent in depression and alcohol misuse populations, with most of the participants in this study reporting traumatic event exposure (71.6% n = 159), and over a third with current PTSD (38.0%, n = 84). Contrary to other studies, there were no gender differences in rates of traumatic exposure, number of traumatic events, and PTSD. More severe PTSS and PTSD were associated with: childhood neglect; earlier depression onset; more severe depression and alcohol problems; and lower general functioning. On the basis of this study it was recommended that, traumatic event exposure, PTSS severity and PTSD should be assessed and addressed among people seeking treatment for co-existing depression and alcohol problems. As this chapter has already been published and the expression ‘we’ used throughout that article, the expression ‘we’ has been retained in this thesis for continuity. However, the work contained in this thesis of solely that of the author of this thesis. Chapter 3 explored the effects of assault types (including dysfunctional parenting) on PTSS, MDD, and alcohol use misuse. We found that sexual or physical assault is more likely to be associated with more severe symptoms of depression or alcohol dependence, compared to having no trauma experiences or being involved in a serious accident or natural disaster. We also found that there may be an assault-symptom pathway that differs for sexual assault and physical assault. For sexual assaults, depression severity was predictive of alcohol dependence. For physical assault, alcohol dependence severity was predictive of depressive symptoms. The assault-symptom pathway may be further supported by the finding that depression onset reduced from 29 (no sexual assault) to 14 years when three different sexual assault types were reported. In regards to physical assault, weekly alcohol consumption levels were found to increase from 58 drinks (for no physical assault) to 139 drinks per week when three physical assault event types were reported. The recommendation from this study was that additional research is required to confirm the assault-symptom pathway proposal as well as investigate the effects of past assault exposure on non-PTSD focused treatments. Further research is required to investigate the relationships between sexual assault and experiencing maternal neglect as a child, and physical assault and experiencing paternal neglect when a child. Chapter 4 explored the effect of having severe PTSS and PTSD in a treatment-seeking population who received CBT treatment for depression and alcohol misuse. In this study most of the assessment instruments (for depression and alcohol) were administered at baseline and 3, 6, 12, 24, and 36 months post baseline. As per Chapter 2, the analysis tested for differences between the three trauma groupings of No Trauma, No PTSD, and PTSD. Differences between participants reporting Mild and Severe PTSS were also tested. All follow-up analyses were adjusted for baseline symptoms including gender, days in treatment, and antidepressant medication. This study found that participants with Severe PTSS or PTSD can respond well to treatment for depression and/or alcohol misuse. PTSS severity and rates of PTSD also significantly reduced for the PTSD group at the 3 month follow-up when compared to baseline. Therefore it is recommended that screening for PTSS severity and including trauma-focused interventions in treatment may further improve symptom reduction in people with co-existing PTSS/PTSD, depression and alcohol misuse. Chapter 5 highlighted that although exposure to sexual and physical assault is common in mental health and substance using populations, screening for assaults in treatment settings is frequently overlooked. Therefore, this study explored the effect of sexual and physical assault on PTSS, depression, alcohol misuse, and global functioning after receiving depression and/or alcohol CBT treatment. As per Chapter 4, all treatment outcomes were assessed at baseline and again at 3, 6, 12, 24, and 36 months, post baseline. We found that participants who were exposed to sexual and physical assaults can respond to MDD and/or AUD CBT interventions. We also found differences based upon the assault type the participant was exposed to. For sexual assaults, we found that participants reported similar mean changes in symptom scores and attended (on average) the same amount of treatment sessions as those participants who had not been sexually assaulted. For physical assault exposure, delays in depressive symptom improvement upon treatment completion may occur. Compared to participants who had not experienced physical assault, participants reporting physical assault were more likely to experience poorer comorbid symptom outcomes at 12 month follow-up. If two physical assault types were experienced, participants spent significantly less time in treatment, attending (on average) only two treatment sessions, and they were less likely to be prescribed antidepressant medication. Based on these findings, it is recommended that assault type and number of assault experiences be screened for and considered in treatment formulation within treatment settings. The final chapter (Chapter 6) reviewed the available treatment guidelines for PTSD, MDD, AUD, and sexual and physical assaults. In this review it was identified that these guidelines are based on evidence in the context of a single or dual disorder(s). It was also identified that the guidelines did not address multiple comorbidities (i.e., three or more disorders). To provide a rationale for addressing gaps in existing guidelines and the literature, the findings of the studies in this thesis are then summarised. Based on these findings and in conjunction with current treatment guidelines, recommendations for PTSD-MDD-AUD and assault presentations were made. The first recommendation made is for the assessment of PTSS in non-PTSD settings. The proposed assessment process would be to utilise a stepped-care approach and commences with the patient being asked one or two screening questions for PTSD. If the question(s) were answered affirmatively, then a psychometrically sound, brief PTSD screening questionnaire would follow. If PTSD symptoms are identified as moderate or severe, then further assessment and possible referral to a specialist health care worker or service is advised. Treatment recommendations are also made in the final chapter. One recommendation is for appropriate health care workers in non-PTSD (i.e., primary/health care, mental health, and alcohol and other drug) treatment settings to be trained in trauma-focused interventions. This training would also include how to identify PTSS and when to refer the patient on to more specialist health care workers and services (such as sexual assault services). Based on the findings presented in this thesis, it is further recommended that presentations of severe PTSS or PTSD with MDD-AUD should be offered integrated PTSD-MDD-AUD treatment. It is recommended that patients reporting a history of sexual assault should initially focus on PTSS and depression, while patients reporting a history of physical assaults should first focus on AUD and then PTSS. Limitations of the studies included in this thesis have been individually reviewed in Chapters 2 - 6. The limitations that are repeatedly highlighted across all the chapters include the parent study targeting treatment for depression and/or alcohol misuse populations, such that not all subjects had a history of PTSD. Therefore the results of these studies may not be reflective of a PTSD or an assault population. Small sample sizes may have also affected the findings, as some analyses were not conducted in some of the chapters (4 and 5) due to issues of power. In Chapters 3 and 5, the findings for the impact of sexual assault on symptoms and treatment may be biased by gender, due to the significantly higher proportion of females reporting sexual assault compared to males. Analysis was further restricted for paternal neglect due to large amounts of missing data (Chapter 5). Given the above limitations, the findings of this thesis thus need to be viewed with caution. Further research is required to confirm the findings of the individual studies as well as for the proposed assessment and treatment recommendations made in Chapter 6. In particular, research is strongly recommended into the effects of parental neglect on assault exposure and experiencing psychiatric symptoms when an adult. Another research area that is particularly recommended is on determining whether there is an assault-symptom pathway for sexual and physical assault, and if treatment of these assault symptoms needs to be sequenced in a particular order. Another important research area is to investigate the benefits of screening and treatment of PTSS in patients who present for treatment for depression and alcohol misuse