The Efficacy of Transcranial Magnetic Stimulation - Essay Example

?Evaluating the Efficacy of Transcranial Magnetic Stimulation For The Treatment Of Patients with Major Depressive Disorder: A Mulicentric Analysis Background of the Study Major depressive disorder (MDD) is perhaps the most widely experienced of psychiatric disorders. It can dramatically affect how functionally people can navigate their lives (e.g., perform daily activities, hold steady employment). MDD also can strain relationships with friends, family, and significant others. Major Depressive Disorders are comorbid in nature. The main conditions found in comorbidity to MDD includes Obsessive Compulsive disorder,Post Traumatic Stress Disorder and the Panic Disorders. (Kessler,1996) Currently the treatment of MDD is centred around the selective serotonin reuptake receptor inhibitors (SSRI). This is based on the fact the main mood elevator neurotransmitter of our body and found at synaptic junctions are actively reuptake so the availibilty of serotonin at the synapse decreases, reducing the mood and causing depression. SSRIs inhibits this uptake by inhibiting the reuptake receptors of serotonin in the presynaptic regions found in the nucleus accumbens and ventral tegmentum area and hence causing mood elevations. Although antidepressant medications are often prescribed to people with MDD, it is estimated that 20-40% of depressed people do not benefit from taking medication ( Kirsch 2008,Hays,1995)).Apart from the efficacy these medications can also cause side effects like drying of mouth, insomnia and others amongst the few. Thus, researchers are developing other possible ways to reduce depressive symptoms. One such depression treatment alternative to medication is the transcranial magnetic stimulation or TMS. Briefly, TMS treatment involves placing a coil on the scalp surface and passing a current through it (the exact details of the strength and rate of the current are beyond our purposes). When the current passes into neural tissue it affects the way the neurons operate, in a therapeutic way. Objective and Aim of the Study We wanted to analyze whether the TMS approach is effective in reduction of the episodes of depression from the baseline levels at the end of week 4 in the major depressive disorder patients. Methodology The study was conducted across multiple sites but the procedures were the same across locations. The sites involved were Florida, Oregon, and Washington. Across locations, participants with a history of antidepressant-resistant MDD were randomly assigned to either an active or a sham TMS condition. In the active condition, participants were actually given the TMS treatment. In the sham condition, participants were not given the TMS treatment but went through a similar procedure in each session (e.g., they came in for sessions in which a coil was placed on their heads but no current was run through it). So the sham condition was considered to be a type of placebo treatment. This was done to minimize the treatment limited bias of the study. The study was run double-blind so that neither the participant nor the assistant running the session was aware of which condition the participant was in. Thus the experimental design of the study was a randomized, multicentric, placebo controlled double blind study. This design definitely was important to give the way for a powerful analysis. The MADRS scores which is the set of scores that signifies the extent of depression of various parameters were analyzed to give a final depression score. The convention is, more the MADRS scores more is the depression and vice versa. Thus the results were analyzed by comparing the MADRS scores at baseline and at 4 weeks after the TMS treatments were implemented to see the effect of that approach on MDD patients. Statistical analysis was carried out through SPSS software and paired sample t test was carried to find out the levels of significance. P values less than 0.05 were considered statistically significant. Results We analyzed findings on 4 questions to reach a conclusion. Q1.Ignoring the TMS condition and site for the moment, were depression scores significantly lower, on average, four weeks into the study compared to at the beginning of the study? Fig1: The above findings was used for the first question which represented the mean MADRS scores Yes the depression scores were lower significantly on four weeks into the study (28.3) versus at the beginning of the study(35.7).There was a mean difference of 7.43 and the results were statistically significant as the p values were less than 0.05( it was 0.0001) which means this observation of happening due to chance is even less than 1in 100 observations and thus 99 observations suggests that the mean depression scores are less into 4 weeks of treatment in 99% of the patients. The graph below describes the finding Fig 2: Comparison between mean MADRS scores at baseline and at 4 weeks after TMS approach. Q2. Focusing only on depression scores at week 4, were depression scores significantly lower, on average, for people who were in the active compared to the sham TMS condition? Fig 3: The above findings was used for the first question which represented the mean MADRS scores between sham conditions and active treatment with TMS conditions Yes, depression scores were significantly lower in active group (22.16) versus the sham TMS condition(34.18) on the fourth week as seen from the p values of 0.0001 which is less than 0.05 that means the null hypothesis of happening due to chance was rejected which means this observation of happening due to chance is even less than 1in 100 observations and thus 99 observations suggests that the mean depression scores are less into 4 weeks of treatment in 99% of the patients and there was significant difference in 99 observations of active group than the sham TMS condition which were lower than the sham TMS conditions. This means that the TMS technology was significantly better than the placebo approach justifying the efficacy of TMS. Fig 4: Compares the mean MADRS scores between sham conditions and active treatment with TMS conditions Q3. The location of the study (3 levels) and TMS condition (2 levels) creates 6 different groups of participants. Focusing again on depression scores at week 4, were there any differences in depression levels among these 6 groups? There was significant differences in week 4 when isolated the TMS conditions were considered (p values 0.0001 which is less than 0.05 that means the null hypothesis of happening due to chance was rejected and also in case of significant differences occurred when only Sites were being considered p values 0.0001 which is less than 0.05 that means the null hypothesis of happening due to chance was rejected. This means at some centres patients responded to the TMS approach significantly better than the other centres and even in some sites the results were superior. But when the total TMS conditions along with the various sites were being considered then there was no significant difference (p=0.215 so the p value was >0.05) and in this case the null hypothesis could not be rejected and this signifies based on the different conditions irrespective of the sites the treatment protocol was universally implemented. Fig 5: Data set for question 3 and 4. Q4. Regardless of whether or not the answer to question 3 was significant, report on the interactive effect of sites and TMS condition on depression scores at week 4. The interactive effects of site and TMS indicated that based on the different conditions (TMS conditions) and irrespective of the sites the treatment protocol was universally implemented and the results were quite similar(p value was 0.215) meaning 88% of the cases similar results occurred and the null hypothesis was not rejected. Discussion and Conclusion From the above findings we can certainly infer that the application of TMS therapy caused significant reduction of MADRS scores or depression scores and it was evident when all sites and conditions were taken in a totality indicating the success for the approach universally, It was noted that on week 4 depression scores were less in the active group than in the sham TMS group. References Hays RD, Wells KB, Sherbourne CD(1995). Functioning and well-being outcomes of patients with depression compared with chronic general medical illnesses. Archives of General Psychiatry.;52(1):11–19 Kirsch I, Deacon BJ, Huedo-Medina TB, Scoboria A, Moore TJ, Johnson BT (2008). "Initial severity and antidepressant benefits: a meta-analysis of data submitted to the Food and Drug Administration". PLoS Med. 5 (2): e45. Kessler RC, Nelson C, McGonagle KA(1996). Comorbidity of DSM-III-R major depressive disorder in the general population: results from the US National Comorbidity Survey. British Journal of Psychiatry;168(suppl 30):17–30. Read More