Article Review: Attention Deficit Hyperactivity Disorder

Introduction

Understanding the theoretical framework, research design, methodological approach, and statistical analyses of a given study is pivotal to evaluating its validity and applicability to a particular research topic. Similarly, consideration must also be given to the type and quality of the journal in which the study is published. Therefore, the purpose of this paper is to critically analyze the scientific rigor of a recent study within the field of biology. An overview of the journal in which the study is published is first provided, followed by a detailed critique of the article itself. Consideration will then be given to the degree to which this article adhered to the journal's requirements. Finally, a reflection on personal lessons learned in conducting this critique will be provided. This paper concludes with a brief summary and an outline of key points.

Overview of the Journal

The study in question was published in ADHD Attention Deficit and Hyperactivity Disorders, a journal oriented toward the investigation of ADHD. According to its mission statement, this journal seeks to publish contemporary research from multiple disciplines to provide a holistic depiction of the causes, symptoms, pathophysiology, and treatment of ADHD in human subjects. ADHD Attention Deficit and Hyperactivity Disorders draws from biological, psychological and clinical research in an attempt to further the "understanding, diagnosis and treatment of all psychiatric syndromes in which attention-deficit disorder (ADHD) may be a feature" (Springer, n.d., para. 2).

Upon scouring several recent editions of the journal, it appears that the editors to not favor a particular academic discipline, instead encouraging researchers from all relevant fields to contribute. For example, Dittman, Wehmeier, Schacht, Lehmann, and Lehmkuhl (2009), a group of psychiatrists, recently published a study in the journal that sought to consider the psychometric properties of an instrument designed to assess self-esteem in patients with ADHD. Conversely, Johnson and colleagues (2012) recently evaluated the role of fatty acids in the perpetuation of ADHD symptoms. Therefore, it is apparent the ADHD Attention Deficit and Hyperactivity Disorders seeks to encourage participation from several independent disciplines.

In addition to original research papers, ADHD Attention Deficit and Hyperactivity Disorders publishers critical reviews and meta-analyses, independent case studies, communications and reactions to research, and letters to the chief Editor (i.e., M. Gerlach). According to its webpage, this journal is currently only available in English and favors an academic, scientific linguistic style (Springer, n.d.). As mentioned on the page, all original research papers within this journal follow a similar academic writing style and structure, including an abstract, introduction, methods, results, discussion, and references section. Each section provides relevant information as its title suggests. For example, the abstract provides a summary and overview of the purpose of the study, design, results, and conclusions. Similarly, the introduction highlights the significance of the study and reviews literature specific to the topic of interest. The methods section outlines the theoretical framework, research design, participants, procedures, materials, and instruments of measurement. The results section includes data analyses, tables, and figures that help summarize answers obtained for each research question. The discussion section provides an interpretation and implications for each of the major findings of the study. Future directions and implications for practitioners are also included in most studies published within ADHD Attention Deficit and Hyperactivity Disorders.

Overview of the Article

The current study being reviewed is titled, "Effects of DSP4 and methylphenidate on the spatial memory performance in rats," and was authored by Sontag, Hauser, Tucha, and Lange (2011), a group of experimental and clinical psychologists from Europe. The specific qualifications of the authors are not listed, although a quick review of the literature shows that the lead author has published or co-authored numerous previous studies in this field. Specifically, Sontag has conducted previous studies regarding the impact of DSP4 on spatial memories in rats, as well as the efficacy of relying on animal models in the investigation of ADHD. Using animal models to explore human psychological issues is obviously associated with some potential confounds, and Sontag reflects on several of these in a critical review of literature in this area. Having published studies in this area previously, Sontag appears to be an expert on ADHD in both animal and human models.

In this study, Sontag and colleagues (2011) sought to examine the "spatial memory performance of rats following a central noradrenaline depletion induced by three different doses of the neurotoxin N-(2-chloroethyl)-N-ethyl-2-brombenzylamine (DSP4)" (p. 351). Additionally, these researchers examined the same outcome following the provision of three doses of methylphenidate (MPH). As previous research has revealed the connection between heightened motor activity and the presence of ADHD symptoms, as well as the potential connection between psychostimulants and an increase in neurotransmitters that help alleviate such attentional disruptions, these researchers sought to more fully understand dose-specific responses to these chemicals in more detail. The academic and practical implications of understanding the impact of various doses of these aforementioned psychostimulants are obvious and may lead to more efficacious prescriptions in human subjects. While research has expansively explored the neurochemicals involved in ADHD, there is less information as to the precise dosages needed for various human subjects. The information gained from this study helps shed light on this gap in research.

Based on the significance of this study in promoting more efficacious medication dosage, this study clearly matches the scope and requirements of ADHD Attention Deficit and Hyperactivity Disorders. Specifically, this study cites several works previously published within the same journal, illustrating the theoretical and conceptual continuity advocated by the Chief Editor. This study utilizes the same academic linguistic approach used by nearly all previous works published within ADHD Attention Deficit and Hyperactivity Disorders. The structure of this article follows that described above, including an abstract, introduction, materials and methods, results, discussion, and reference section. Each section follows a similar pattern to those of previous studies. For example, the abstract outlines the purpose, procedures, results, and conclusions drawn from the study. Specifically, Sontag and colleagues (2011) summarize their study hypotheses and describe the three levels of DSP4 used in their animal models. Furthermore, these researchers use the abstract as an opportunity to highlight the potential implications of this study for biologists, psychologists, and clinicians.

The introduction section defines the significance and necessity of the study, as well as gaps in previous research related to this topic. In this section, Sontag and colleagues (2011) discuss the role psychostimulants play in the perpetuation of ADHD symptoms, as well as highlight several gaps in research on this topic. For example, Sontag and colleagues (2011) indicate that there is a relative paucity of information regarding how to effectively increase catecholaminergic activity in human subjects, and how varying levels of psychostimulants can help alleviate the symptoms of ADHD. Finally, the significance of the study is presented in the introduction section, which Sontag and colleagues (2011) assert is to provide further insight into how to ultimately increase noradrenaline within the prefrontal cortex.

The material and methods section defines the study sample, methods of instrumentation, and procedures followed. In this study, Sontag and colleagues (2011) utilized 48 male rats within a laboratory setting to evaluate the impact of varying levels of DSP4 in the amelioration of ADHD symptoms. These researchers divided the rats into four groups of 12, including the three treatment groups and one control. Sontag and colleagues (2011) tested the three different levels of DSP4 over the course of two weeks, consisting of 10 separate trials. In this section, these researchers further described their consideration of extraneous variables, such as feeding schedules and weight. Finally, the intended statistical procedures were outlined, including the use of a series of non-parametric Wilcoxon tests.

The results describe the major findings of the study, including figures and tables that help readers visually conceptualize the main outcomes. The main outcome of this study was that DSP4 did not have a significant impact on cognitive abilities (i.e., spatial memory). Furthermore, these researchers found that none of the DSP4 dosages produced significant changes in the noradrenergic system, indicating that solely changing these dosages is not likely to alleviate ADHD symptoms in human subjects. Additionally, these researchers found that the administration of DSP4 did not significantly impact feeding schedules.

The discussion section provides an interpretation for each finding, as well as possible theoretical and practical underpinnings. Previous research was cited throughout in order to paint a picture as to how the current findings fit in with the larger body of knowledge related to the role of neurotransmitters in the perpetuation of ADHD. Interestingly, these findings conflict with some previous research on this topic, and Sontag and colleagues (2011) provide several explanations as to why this was the case. Specifically, other studies have shown that DSP4 does have an impact on various cognitive abilities in animal models. However, Sontag and colleagues (2011) were among the first to explore the effect of varying dosages on spatial memory. One novel finding was that MPH appeared to raise levels of impulsivity and motor activity in rats, illustrating the possible connection between this chemical and two of the most common symptoms of ADHD (Sontag et al. (2011). Directions for future research are also provided in the discussion section. The reference section provides information needed to locate all works cited in the study.

Adherence to the Journal's Purpose

Upon reviewing the methods, results, and conclusions drawn from Sontag and colleagues' (2011) study, it is apparent that this research clearly fits within the scope and purpose of ADHD Attention Deficit and Hyperactivity Disorders. As the purpose of this journal is to present contemporary research that may be useful in understanding and treating ADHD, the results from Sontag and colleagues' (2011) research effectively fulfill ADHD Attention Deficit and Hyperactivity Disorders' stated intentions of bringing together "biological, clinical and psychological research" related to ADHD. Furthermore, these authors appear to provide implications for each of these academic disciplines. The physiological underpinnings of the neurotransmitter responses to different doses of psychostimulants used in this study are particularly beneficial to biologists seeking to establish a more detailed pathophysiological understanding of ADHD. Additionally, the conclusion that a reduction in noradrenaline and an increase of dopamine would likely increase ADHD symptoms is useful for clinicians and psychologists who work directly with children with this disorder. While the rat and human brains differ in numerous ways, this study seems to provide direct evidence of the impact of certain psychostimulants on cognitive functions such as spatial memory.

Lessons Learned

In conducting this brief review article and journal, I have learned several lessons about researching, writing, and publishing within my field. First, I have learned the value of exploring different journals prior to publishing a study. Various journals have different scopes and purposes, and understanding these factors is helpful in ensuring that a potential study achieves publication. Additionally, understanding the manuscript requirements and language used within a particular journal can help both researchers and editors avoid time-consuming editing and review processes.

Second, I have learned that understanding the qualifications and previous works of authors is an important step in evaluating the validity and applicability of a particular study. While previous accomplishments should not be the only evaluation criterion when critiquing the rigor of a study, this information can be helpful in determining the credibility of some authors. One would not lend as much credence to a study published by a group of authors with just baccalaureate degrees, for instance, as he or she would to a group with doctorates. Similarly, one might be inclined to place greater value in research conducted by a well-established author within a given field, as opposed to one who is relatively new to the subject.

Finally, the importance of carefully reviewing the content of a study, including the significance, methodology, and statistical approach, cannot be overestimated. Even in mainstream journals, most studies are rife with potential biases and sources of error. An in-depth understanding of these potential drawbacks can help the reader better assess the merit of a particular study.

Conclusion

The purpose of this paper was to critically review a recent study related to ADHD. An overview of the journal in which the study was published was first provided, followed by a critical analysis of the contents of the study itself. The degree to which this study adhered to the journal's requirements was then considered, followed by a description of personal lessons learned in performing this review. Based on the information gathered from conducting this review, it is evident that a detailed understanding of a particular journal's requirements, scope, and purpose are important in evaluating the validity of an original piece of research published within one of its volumes. Additionally, carefully reviewing the contents of the study is essential in determining its scientific merit.

References

Dittman, R. W., Wehmeier, P. M., Schacht, A., Lehmann, M., & Lehmkuhl, G. (2009). Self- esteem in adolescent patients with attention-deficit/hyperactivity disorder during open-labelatomoxetine treatment: psychometric evaluation of the Rosenberg Self-Esteem Scale and clinical findings. ADHD Attention Deficit Hyperactivity Disorders, 1(2), 187-200.

Johnson, M., Mansson, J.-E., Ostlund, S., Fransson, G., Areskoug, B., Hjalmarsson, K., ... (2012). Fatty acids in ADHD: plasma profiles in a placebo-controlled study of Omega 3/6 fatty acids in children and adolescents. ADHD Attention Deficit and Hyperactivity Disorders, 4(4), 199-204.

Springer (n.d.). ADHD Attention Deficit and Hyperactivity Disorders. Retrieved from: http://www.springer.com/medicine/psychiatry/journal/12402. Accessed 7 October 2013.

Sontag, T. A., Hauser, J., Tucha, O., & Lange, K. W. (2011). Effects of DSP4 and methylphenidateon spatial memory performance in rats. ADHD Attention Deficit and Hyperactivity Disorders, 3, 351-358.