As part of this literature review, literature that focuses on the effectiveness of cognitive behavioral therapy (CBT) as a treatment for Depression and anxiety will be examined and evaluated. Firstly, it is important that CBT is defined and understood as a “structured, goal-directed and collaborative intervention strategy” (Clark, 2014 cited by Mothersill, 2016) to work towards the exploration and understanding of psychological disorders of an individual (Mothersill, 2016). This is important as it should be recognized individually compared to other therapeutic methods in counseling. It is also important that when evaluating the effectiveness of CBT you are specific in what you hope to achieve through the use of this therapy. For example, CBT may treat a certain disorder but not another. This means that it is important to specify what you want CBT to cover. As part of this literature review, research on the effectiveness of CBT in the treatment of depression and anxiety will be critically examined. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Many forms of research use self-report as an experimental design, this can be seen as a strength or weakness. A weakness of research using self-report is that people may not respond truthfully and therefore the results become invalid, furthermore this can influence the definition of cause and effect within the research. For example, Norell-Clarke et al (2015) studied the effectiveness of CBT and relaxation training (RT) on participants with depression. Norell-Clarke et al (2015) recruited 64 participants via advertisement to receive CBT or RT to treat insomnia and depression, as the two diagnoses are closely linked. Norell-Clarke et al (2015) then assessed their participants using the Insomnia Severity Index and the BDI-11, pre-treatment, post-treatment and six-month follow-up self-reports. They also asked participants to keep a sleep diary one week before treatment and for the duration of treatment. Norell-Clarke et al (2015) found that CBT was more effective in treating insomnia and depression than RT. However, CBT had a higher readmission rate than RT. Norell-Clarke et al (2015) rely completely on self-report methods to confirm their findings, therefore the results may be biased and invalid, as participants may be making up their answers. Norell-Clarke et al. (2015) should have used a more reliable method of data collection to improve the credibility of their research. Therefore, this literature is not very helpful in predicting the effectiveness of CBT as a treatment for depression. Conversely, self-report can be a useful data collection method. This is because self-report allows researchers to examine a large number of variables, and they can ask participants to reveal information about their behavior in a specific real-world situation. Additionally, self-assessment is a much cheaper way of collecting data than many other methods. Anderson, Watson, and Davidson (2008), evaluated whether the use of CBT was effective in reducing anxiety symptoms in a hospital setting. They collected data from structured interviews with patients and analyzed pre- and post-intervention anxiety and depression scores. Anderson, Watson, and Davidson (2008) concluded that CBT was effective in hospitals for patients with mild to moderate anxiety or depression. The useof self-assessment allowed Anderson, Watson, and Davidson (2008) to draw this conclusion. Even with the use of self-report, if the pool of participants is selected randomly and sufficiently large it is possible to generalize the research findings, which increases the value of this research. The research by Anderson, Watson, and Davidson (2008) can therefore be considered a useful piece of research literature on the effectiveness of CBT as a treatment for anxiety and depression. Another strength of the literature evaluating the effectiveness of CBT in treating depression and anxiety is whether researchers use meta-analyses. This is a strength as it brings together more research in order to create a larger pool of participants and allow for precision. Research conducted by Twomey, O'Reilly, and Byrne (2014) used a meta-analysis focusing on CBT and randomized controlled trials to evaluate the effect of CBT on the relief of anxiety and depression symptoms. Twomey, O'Reilly, and Byrne (2014) reviewed 29 randomized, controlled trials and found that multimodal CBT is effective in reviving symptoms of anxiety and depression, within a primary care setting. Using such a large amount of research means that a more definitive conclusion can be reached, individual research findings are often inconclusive, and meta-analysis helps remove this problem. On the other hand, the use of meta-analysis can be considered as a big deal as it simply uses other people's research and reanalyzes it to determine the results. The research analyzed may be biased and unreliable. An example of an article that uses meta-analysis and is a systematic review is the article by Bird et al (2010) who reviewed previous research to find the effectiveness of early intervention and CBT on early psychosis such as depressive psychosis. Bird et al (2010) carried out a systematic review and meta-analysis of randomized controlled trials. They found that CBT was helpful in reducing the severity of symptoms, but did not prevent hospitalization or reduce relapse rates. While this may appear to be a useful finding, there is no certainty that the research assessed by Bird et al (2010) is valid and therefore it may mean that the Bird et al (2010) literature does not measure what it was originally intended to do. A strength, however, of literature research on the effectiveness of CBT as a treatment for depression and anxiety is the fact that researchers in this field often perform follow-up evaluations. Follow-up assessments are useful for research because they allow the researcher to see whether CBT was effective over the long term, not just immediately after participants received therapy. If the researcher can see that CBT is effective in the long term, it is worth investing money in future use of the therapy. An example of research consistently tracking depression and anxiety in participants with Parkinson's disease is Troeung, Egan, and Gasson (2014). 18 adults suffering from Parkinson's disease, depression and/or anxiety participated in this research. Participants were randomly assigned to the eight-week CBT intervention or the waitlist. Troeung, Egan, and Gasson (2014) then followed CBT progress before treatment, after treatment, one month, and six months after treatment. This is useful in research as they can tell if adults found CBT beneficial, they also had a control group they could use to compare the effectiveness of CBT for this type of mental health disorder. The use of follow-up assessments increases the value of research into the effectiveness of CBT as a treatment fordepression and anxiety. A weakness of the literature evaluating the effectiveness of CBT as a treatment for anxiety and depression, on the other hand, is that much of the research struggles to find a sufficient sample size. This is because participant requirements are quite specific, which limits the number of individuals researchers can use in their experiments. Urao et al. (2016), conducted a quasi-experiment in Japan, which involved a CBT anxiety intervention group of thirteen participants, recruited using advertising posters, and a control group of sixteen participants. As part of the research, the child and parent reported symptoms of anxiety within the Spence Children's Anxiety Scale. Urao et al. (2016) found that CBT was partially effective based on parent ratings. The use of 29 participants represents an extremely small sample size and means that the researchers were unable to generalize their findings to all children in Japan. A small sample size may also be the reason why research findings were relatively inconclusive, claiming that CBT was only "partially" effective. Therefore, using a small group of participants negatively impacts the usefulness of research on the effectiveness of research on CBT as a treatment for anxiety and depression. The literature evaluating the effectiveness of CBT as a treatment for anxiety and depression is extremely specific in its participant selection process. This is beneficial to the validity of the research as it means that the findings and conclusions can be more easily generalized to the entire population of that specific group. For example, Chorpita et al. (2004) selected eleven participants, all had to be between the ages of seven and seventeen, all had been referred for CBT at the University of Hawaii, all had to have a DSM diagnosis of anxiety. The specific needs of the participants in this research mean that in general everyone is experiencing the same situations, for example school, homework, learning new skills, etc. This means that researchers were more easily able to generalize the findings to children aged seven to seventeen. Chorpita et al. (2004) found that at the post-CBT assessment all children were absent from anxiety symptoms, the same was true at the six-month follow-up assessment. Therefore, Chorpita et al. (2004) concluded that “there is initial support for the use of…CBT for anxiety disorders in young people” this ability to generalize to “young people” is only possible due to the small sample while eleven individuals of all ages they would not have been so generalizable. This benefits the research literature on the effectiveness of CBT as a treatment for anxiety and depression. Much of the research conducted in this field does not recognize any confounding and extraneous variables. Extraneous variables can have a considerable effect on the collected results and therefore should be controlled. For example, Scott (1992) took eight in patients who met diagnostic criteria for depression and prescribed CBT for twelve weeks. Every three weeks Scott (1992) measured patients using the Hamilton Depression Rating Scale, the Beck Depression Inventory, self-rating of mood, and the Nurse Observation Scale for patient assessment. Scott (1992) found statistically significant evidence of reduction in depression, however, much of the symptoms and morbid thoughts continued. Scott (1992) did not consider any extraneous variables that might influence the extent to which patients are.