Abnormal Psychology


The study reflects the cognitive and biological models of abnormality. The cognitive model focuses on cognitive deficiency and its relation to mental illness (Cardwell & Flanagan, 2005). Practitioners who use cognitive model health illnesses are caused by thought processes and can be treated by changing patient’s maladaptive thought patterns. The second group of participants in this study received cognitive behavioral therapy (CBT), which aims at changing patients thought patterns. Biological model associates mental illness with neuroanatomy and biochemicals that mediate psychological processes. Practitioners who use biological method use medications to treat mental health illnesses. In the study, the first group is approached using a biological model, where they are treated using antidepressants.

Researchers could have tested the behavioral model, which entails adaptive or maladaptive behaviors. Practitioners who use this model believe mental health illness can be treated using behavioral manipulation. For instance, the researcher could have used reward and punishment to enhance behavioral patterns.


Random Assignment and Random Selection

The researchers begin by randomly selecting 45 participants from a population depressed client in each mental health centers. The random selection process is based on the score of equal or less than 20% for MMPI-2-RF and the Beck Depression Inventory, and equal or less than 30% on the Beck Depression Inventory. That is wrong since it does not offer all the 285 client’s equal chances to participate in the study. The random assignment method entails assigning a treatment method to the 135 participants in the three mental health centers. Each center has three categories which represent a model, assigned to 15 participants. This does not seem right since each model is administered in different conditions – since all the centers can seldom have similar conditions. That violates the balancing criteria for randomization.

The researchers could have randomly selected participants from the lowest to the highest scores for MMPI-2-RF, the Beck Depression Inventory, and the Beck Depression Inventory using the chance mechanism. For the purpose of balance, similar conditions should have been used, such as the same practitioner for each model.


The study is moderately generalizable. First, it is focused on a fairly specific population. There are many abnormal psychologies, but the study only considers clients with depression. That way, the findings of the study are not applicable to all abnormal psychologies. Secondly, the sample size is not sufficient to make it highly generalizable. Among all the clients with depression, only those who have a score equal or less than 20% for MMPI-2-RF and the Beck Depression Inventory, and equal or less than 30% on the Beck Depression Inventory were assigned. The other portion of the population was not studied, yet it has significant characteristics. For instance, it was the largest. Nevertheless, the study is generalizable since its findings primarily reveal universal application. Results from the three mental health centers revealed similarity. Therefore, the study is generalizable, though moderately.

Generalizability is important, especially in abnormal psychology, since it helps establish interventions at minimal costs (Banerjee & Chaudhury, 2010). Notably, researchers use a sample from a population to study abnormal psychology and use the findings (if generalizable) for the whole population. While researchers can seldom achieve absolute generalization, it is even much challenging to conduct a study on the whole population. It would require a lot of resources and have huge margins of error and bias. Generalization help mitigate these shortcomings.


The independent variable for this study is the participants, and the dependent variable is the mental health outcomes of participants. The participants are grouped into three categories, which are manipulated across three models of abnormality (Flannelly et al., 2014). As such, participants are the independent variable. The results of the manipulation of models of psychology on the participants are the dependent or outcome variable, for which the best model is accessed.

Another ideal independent variable would be the models of abnormality, which would be manipulated to identify their outcomes on the period of administration – the dependent variable. For a given period of time, the mental health outcomes for each model would be accessed to identify any statistically significant results.


This study is not correlational. A correlational study is that which scientists passively observe a phenomenon, and measure the results. They are not actively involved in the processes involved. However, researchers in this study gave participants antidepressants, behavior therapy, and keeping other participants waiting to see a practitioner. Also, correlation studies do not involve the manipulation of variables. In this study, independent variables are manipulated such that three groups each is administered a model to measure their outcomes. Therefore, this study aims at finding the course and effect of the mental health illness and the outcomes for each model of abnormality. This is unlike correlation studies which only observe to identify patterns of relationships. Lastly, correlation studies have only two variables, yet, there are more than two variables in this study.


Banerjee, A., & Chaudhury, S. (2010). Statistics without tears: Populations and samples. Industrial Psychiatry Journal, 19(1), 60. https://doi.org/10.4103/0972-6748.77642

Cardwell, M., & Flanagan, C. (2005). Psychology AS. Nelson Thornes.

Flannelly, L., Flannelly, K., & Jankowski, K. (2014). Independent, Dependent, and Other Variables in Healthcare and Chaplaincy Research. Journal Of Health Care Chaplaincy, 20(4), 161-170. https://doi.org/10.1080/08854726.2014.959374