Nameof Journal:Journalof Psychiatry & Neuroscience: JPN.
Journalvolume, date, and year:vol.41, August 30, 2016.
Title of experiment:Theeffect of methylphenidate intake on brain structure in adults withADHD in a placebo-controlled randomized trial
Author(s):LudgerTebartz van Elst, Simon Maier, Stefan Klöppel, Erika Graf, CarolaKillius Marthe Rump Esther Sobanski, Dieter Ebert, Mathias Berger,Andreas Warnke, Swantje Matthies, Evgeniy Perlov, and AlexandraPhilipsen.
I. Statethe Hypothesis-The hypothesis of the experiment was that long-term administration ofMPH (Methylphenidate) alters the regional or global cerebral volume.The experiment sought to prove whether the study was positive ornegative.
Intheir background to this particular study, the authors provideevidence from different animal research experiments that inform theirwork. According to the experiments done on animals, MPH is tolerated.However, debate exists in the media as well as scientific literatureregarding the safety of the treatment with MPH concerning cerebralhealth. The inadequate available evidence obtained from animalresearch has indicated that the administration of MPH to small ratsleads to an insistent lowering in the concentration of striataldopamine transporters. The outcome of the animal tests caused adiscussion in the public regarding the possible long-term damage thatMPH can cause to the basal ganglia as well as the induction of theParkinson disease symptoms. The authors mention a recent experimentdone on mice that involved the chronic administration of MPH usingthe stereological counting approaches. According to this recenttrial, a significant reduction in DA neuron quantities in thesubstantia nigra was witnessed. Equally observed was a sizableupsurge in the quantities of activated microglia in the substantianigra. A number of meta-analysis, as well as neuroimaging studiesdone in humans, had indicated that MPH exerted normalizing effects onthe brain structures in adolescents and children. The studybackground is regarded as integral in informing the purpose a well asjustification of the experiment.
b.Prolonged administration of MPH (independent variable) is likely toalter the regional or global cerebral volume (dependent variable).
c.Problem statement – Severalanimal research works had warned that using MPH, which is thefirst-line drug applied in the treatment of ADHD, could causeneurotoxic effects with potential to harm the brain. Therefore, thisstudy sought to investigate whether the application of MPH over aperiod of one year resulted in cerebral volume decrease. The researchwill help provide vital information on the treatment of ADHD and theside effects of using MPH as a first-line management option. Thestudy findings are relevant in pharmacotherapy that considers MPH andother stimulants as useful options for treating both adults as wellas children.
II.Measurement of Variables
a.Dependent Variable-The dependent variable in this experiment was the alteration(increase or decrease) of the regional or global cerebral volume. Thedependent variable was measured by acquiring structural MRIs in thedouble-blind study that compared the MPH and placebo. The regional orglobal brain volumes were assessed at baseline using thediffeomorphic registration via exponentiated Lie algebra.
b.Independent Variable-The independent variable was the prolonged administration of MPH.Participants were grouped into two cohorts (the MPH and placebo) andadministration of MPH done after 3 months as well as 12 months. Theindependent variable was measured in terms of time that involvedadministration of MPH over a period of one year. The participantsgiven MPH had initially passed the prescreening process that involvedenrolling only the patients with ADHD.
c.Control variables(s):The controlled variable or the placebo cohort comprised of 29participants who were not given the MPH.
a.Was it valid?
Thestudy design used by the researchers was experimental, which wasvalid. Given that the authors were undertaking an empirical studythat involved testing the effects of a treatment intervention on theglobal cerebral volume, the most appropriate design was the oneapplied.
b.Are there any biases?
Anassessment of the sampling procedure shows that there are no biasesin the experiment. For patients to be invited to take part in thestudy, they had to pass the prescreening stage that everyone wassubjected to thereby making it unbiased.
c.Does the design make sense?
Thedesign makes sense in the view that it included all the hallmarks ofan experimental study. These include the experimental and the controlgroup, which were provided in this research as the MPH and theplacebo cohort.
d.Is there anything that you would have done differently in thedesign?
IfI were undertaking this experiment, I would have increased the numberof participants to reduce the margin of error and collect more datafor an explicit representation of the findings. A larger number ofparticipants offer a large quantity of data that in turn reduces theerror margin.
e.Was the study sample random?
Itis evident from the methodology that the survey was random giventhose participants who had passed the prescreening process wouldstill be excluded from randomization in the event that they did notfulfill all the eligibility criteria.
f.Are there enough replicates?
Thestudy indicated that there were sufficient replicates based on thefindings.
g.Was the instrumentation used correctly for what was beingmeasured?
Theinstrumentation was used properly in the study to gauge thealteration of the regional or global cerebral volume. The researchersdepended on MRIs to measure the regional brain volume.
Thestudy can be regarded as ethical because the University MedicalCenter Freiburg’s Ethics Commission approved it. Besides, it wasundertaken following the standards outlined in the HelsinkiDeclaration. The study also obtained written informed consent fromall the individual participants prior to including them into theimaging subproject.
a.Data Analysis-An assessment of the data analysis shows that proper statistics wereemployed. The researchers included clear images, tables, graphs, aswell as flow charts that were easy to understand. The pictures usedin the study, which mainly showed the parts of the brain affected byMPH, conveyed information that the text did not have. The analysiswas also inconsistent with the hypothesis because the findings showedthat there was no evidence of grey matter volume following aprolonged administration of MPH in ADHD treatment. Therefore, thehypothesis was proved as negative.
V.Your opinion-I think that this experiment is a good one because of a number ofreasons. First, it is possible to follow the methodology and come upwith findings reflecting the margin of error suggested in the study.The results are also trusted given that the margin of error providedand the threshold is minuscule. The control or placebo used in thestudy was adequate and the sampling unbiased. However, a sample sizeof 131 appears small given that the study was undertaken over aperiod of one year. The sample may also not be a representation ofthe actual picture in the medical center. The experimental evidenceprovided supports the conclusions. I have no confidence in thefindings because they seem to contradict the outcomes of the earlierdone animal research studies. The study is significant topharmacotherapy as well as the treatment of ADHD.
Tebartzvan Elst,L., Maier,S., Klöppel,S., Graf,E., Killius,C., Rump,M., Sobanski,E., Ebert,D., Berger,M, Warnke,A.,Matthies,S., Perlov,E.,& Philipsen,A.(2016).Theeffect of methylphenidate intake on brain structure in adults withADHD in a placebo-controlled randomized trial.Journalof Psychiatry & Neuroscience, 41 (6),1-9.