The Effect of Various Doses of SSRI on the Severity of Depression - Research Proposal

The current study is aimed at investigating the effect of various doses of SSRI (low, medium, and high doses) on the severity of depression. The sample for the study comprised 200 participants picked through simple random sampling and divided into three independent groups, which were then administered different doses of SSRI. The severity of depression was measured using Beck Depression Inventory II scale. A one-way analysis of variance was conducted to explore the impact of various doses of SSRI on the severity of depression. Results of this analysis showed that participants administered low doses of SSRI had the highest BDI-II depression scores (M = 41.60, SD = 6.91), those given high doses of SSRI had the lowest BDI-II depression scores (M = 22.23, SD = 9.46), while those treated with medium doses of SSRI reported average BDI-II depression scores (M = 25.84, SD = 10.49). This shows that in clinical treatment of depression, effective treatment can be achieved if higher doses of SSRI are used. Overall, the results of data analysis revealed that there was a statistically significant difference at the p < .000 level in BDI-II depression scores for three age groups F (2, 197) = 85.98, p < .005.

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Introduction

Depression is a common disorder which, globally, affects more than 300 million people (World Health Organization, 2017). When long-lasting, with severe or moderate intensity, it can have adverse health consequences on the affected individual. Some of the effects of depression include poor employee performance and suicide. Currently, there exist effective treatments for depression, such as selective serotonin reuptake inhibitors (SSRIs) antidepressant medication (Green & Muskin, 2013). SSRIs lower depression through increased concentration of serotonin, a neurotransmitter that transmits impulses between brain cells (Davey, 2011). The mode of action of SSRIs involve blockage of serotonin reabsorption of serotonin, thus increasing its concentration in the brain (Hemat, 2004). Other treatment options for depression include interpersonal psychotherapy and cognitive behavioral therapy (Young & Mufson, 2011).

Many studies have been conducted to investigate the effectiveness of SSRIs in the treatment of depression. For instance, a study carried out by Andersen, Vestergaard, and Lauritzen (1994) aimed at investigating the efficacy and safety of SSRI, citalopram, in the treatment of post-stroke depression, found out that patients treated with SSRI registered a high degree of recovery. Conversely, individuals who were administered placebo reported infrequent recovery. The effectiveness of different doses of SSRI can be measured using Beck Depression Inventory II scale (BDI-II). BDI-II is one of the most widely used self-report instruments for assessing the severity of depression and also for depression screening in clinical practice and the general population (Lee, Lee, Hwang, Hong, & Kim, 2017). In this study, the effect of various doses of SSRI (low, medium, and high doses) on the severity of depression as assessed using BDI-II scale was examined. Results of this study have important clinical applications in the treatment of depression.

Hypothesis

The following hypotheses guided the study:

Null hypothesis: There will be no statistically significant difference in the Beck Depression Inventory-II scores of participants administered low, medium, and high doses of SSRI.

Alternative hypothesis: There will be a statistically significant difference in the Beck Depression Inventory-II scores of participants administered low, medium, and high doses of SSRI.

Methods

Design

A quasi-experimental research design was employed in this study. A quasi-experiment resembles a true experiment but lacks one critical element random assignment (Suter, 2012). Specifically, a simple pretest-posttest design was used. Even though the pretest-posttest design was chosen due to its simplicity, it has several threats to internal validity such as testing, instrumentation, maturation, history, and attrition (Weiner, et al., 2013) which limit the generalizability of findings (Hersen, 2005).

Participants severity of depression was measured using the Beck Depression Inventory-II (BDI-II) before the subjects were administered various doses of SSRI. To determine if SSRI treatments had an impact on participants depression, participants severity of depression was measured using the BDI-II scale after the subjects were administered various doses of SSRI. The BDI-II scores obtained on the second occasion was used as the dependent variable scores.

Participants

The researcher recruited 200 participants through simple random sampling. This sample of 200 subjects was divided into three independent groups. The first group, consisting of 67 participants, were administered a low dosage of SSRI. The second group, comprised of 67 participants, were administered a medium dosage of SSRI. Lastly, the third group, composed of 66 participants, were administered a high dosage of SSRI.

Materials

This study included 200 subjects with major depressive disorder. The aim of the research was outlined to the participants, and their written informed consent obtained from them. The level of depression was measured in the participants using BDI-II scale. BDI-II is a 21-item self-report instrument authored by Aaron T. Beck, Robert A. Steer, and Gregory K. Brown, with each of the items in the scale relating to a specific symptom of depression. The instrument is used to assess both severity and presence of depression in both adolescents and adults (Steer, Ball, Ranieri, & Beck, 1999). BDI-II is a 4-point scale, with each item on the scale rated on a 3-point scale (0 to 3). The scores of all the items are summed to give a composite score, with a total score of 29-63 being considered severe, 20-28 considered moderate, while 0-13 is the minimal range. The instrument has been found to have high reliability of .93 and validity of .93. It is self-scored, and takes 5- 10 minutes to complete, it but can take a considerably longer time in patients with severe depression (Sellers, n.d.).

Participants who showed symptoms of depression based on DSM-IV-TR criteria were included in the final sample. The exclusion criteria in this study included those individuals with drug/alcohol dependence, borderline personality disorder, and sleep disturbance secondary to other factors, such as mental illness. Data analysis was conducted using SPSS V 20.0. One-way ANOVA was carried out to determine whether a relationship exists between SSRI dose (low, medium, and high), the independent variable, and BDI-II scores, the dependent variable.

Procedures

First, the participants were explained the need for the research study. Before various doses of SSRI were administered to participants, the researcher measured the severity of depression using BDI-II, a self-report scale. After that, different doses of SSRI were given to three groups of participants. After completion of the treatments, the participants severity of depression was measured using BDI-II scale so as to find out if treatments decreased the severity of depression or not.

Ethics

Ethical practices of research were followed when conducting this study. First, a consent form was developed and approved by the universitys Research Ethics Board (REB). After the proposal for the current study was reviewed by REB, and permission to conduct the study was granted. Moreover, the researcher maintained confidentiality and anonymity of the participants.

Results

200 subjects with depression were included in the present study. The participants were categorized into three groups and administered low, medium, and high doses of SSRI. A one-way analysis of variance was conducted to explore the impact of various doses of SSRI on participants severity of depression as evaluated using BDI-II and to test the null hypothesis. A one-way ANOVA is used to investigate whether statistically significant differences exist between three or more conditions of the same independent variable (Coolican, 2014). For one-way ANOVA to be conducted in SPSS, the data should meet the following assumptions: homogeneity of variance across the independent groups, the dependent variable should be normally distributed and should also be measured on at least an interval scale or ratio level of measurement (Coolican, 2014).

Results of one-way ANOVA analysis showed that the mean scores for participants given low doses of SSRI had the highest BDI-II depression scores (M = 41.60, SD = 6.91) while subjects given high doses of SSRI had the lowest BDI-II depression scores (M = 22.23, SD = 9.46). Lastly, subjects treated with medium doses of SSRI reported average BDI-II depression scores, M = 25.84, SD = 10.49 (See Appendix A).

Appendix B shows SPSS output reports of assumption of homogeneity of variance (Levenes test). From Appendix B, it can be seen that the assumption of homogeneity of variance has been met, the significance is 0.07, which is larger than 0.05. Appendix C shows that there was a statistically significant difference at the p < .000 level in BDI-II depression scores for three age groups F (2, 197) = 85.98, p < .005. Therefore, the null hypothesis was rejected.

Discussion

The primary objective of this study was to examine the effects of various doses of SSRI (low, medium, and high doses) on the severity of depression as assessed using BDI-II scale. The findings showed that increasing SSRI doses led to decreased severity of depression as indicated by reduced BDI-II scores. Specifically, participants administered high doses had the lowest BDI-II scores, while those who received the lowest dose had the highest BDI-II scores. Similarly, a study carried out by Wiese (2011) reported that if the elderly individuals are unresponsive to low doses of SSRI, higher doses may be needed to achieve a therapeutic effect. This implies that in clinical treatment of depression, effective treatment can be achieved if higher doses of SSRI are used. Also, there was a statistically significant difference at the p < .000 level in BDI-II depression scores for three age groups F (2, 197) = 85.98, p < .005. This shows that different doses of SSRI have different effects on severity of depression.

References

Andersen, G., Vestergaard, K., & Lauritzen, L. (1994). Effective treatment of poststroke depression with the selective serotonin reuptake inhibitor citalopram. Stroke, 25(6), 1099-1104. doi:10.1161/01.str.25.6.1099

Davey, G. (2011). Applied psychology. Chichester: BPS Blackwell.

Green, M. W., & Muskin, P. R. (2013). The Neuropsychiatry of Headache. Cambridge: Cambridge University Press

Hemat, R. A. (2004). Principles of orthomolecularism. Dublin: Urotext.

Hersen, M. (2005). Encyclopedia of behavior modification and cognitive behavior therapy. Adult clinical applications. Thousand Oaks, CA: Sage publications.

Lee, E., Lee, S., Hwang, S., Hong, S., & Kim, J. (2017). Reliability and validity of the Beck Depression Inventory-II among Korean adolescents. Psychiatry Investigation, 14(1), 30. doi:10.4306/pi.2017.14.1.30

Sellers, P. A. (n.d.). Beck depression inventory - 2nd edition. Retrieved from http://www.cps.nova.edu/~cpphelp/BDI2.html

Steer, R. A., Ball, R., Ranieri, W. F., & Beck, A. T. (1999). Dimensions of the Beck depression inventory-II in clinically depressed outpatients. Journal of Clinical Psychology, 55(1), 117-128.

Suter, W. N. (2012). Introduction to educational research: a critical thinking approach. Los Angeles, CA: SAGE.

Weiner, I. B., Freedheim, D. K., Schinka, J. A., Velicer, W. F., Nelson, R. J., Healy, A. F., Mizumori, S. J. (2013). Handbook of psychology. Research methods in psychology. Hoboken, NJ: Wiley.