What is meant by double-blind, randomized controlled trial? Explain why such trials are used in psychological research with reference to one specific, published psychological experiment.
Randomized controlled trials are considered the gold level standard of proof of many research techniques where treatments and therapies are concerned by the scientific community. A study in which participants are allocated at random to receive one of several treatments testing the effectiveness of psychological interventions or pharmacotherapy is known as a randomized controlled trial. This is a scientific study which is conducted by double-blind experiments. In a double-blind experiment neither the researcher nor the participants know who belongs to the control group and who belongs to the experiment group. This helps to eliminate conscious and unconscious bias by experimenter and participants. One variable is manipulated to get a true experiment while other variables are held constant. These trials establish the efficiency of a treatment as well as learn about its side effects. Administering this treatment has been proven to have powerful psychological effects on the participant which is known as placebo effect. Though randomized controlled trials are criticised by some experts these trials are used in psychological research as a means to establish results effects and side effects of a treatment as analysed in a report Psychotherapy and the placebo effect (Rosenthal, D and Frank ,J. D).
Randomized controlled trial is designed to make decisions that address questions like if we have disorder X is treatment A or treatment B going to be effect to treat the disorder? There is always a need to know if there is an alternative treatment and randomized trials help to make a decision the treatment is effective or not. It has been found that placebos are as effective as other ingredients in the reduction of symptoms and distress. In a study of cold vaccines by Diehl, Baker and Cowan (1940 there was a 55 percent reduction in yearly colds among those who received the vaccine and 61 percent among those who injections of isotonic sodium chloride solution. In another study by Jellinek 60 percent of 199 subjects with chronic headaches received relief from a placebo on one or more occasions. Although placebos have no medical benefits they have been proven to reduce anxiety, pain and depression and as result therapists need information about comparative treatments that are efficient and randomized trials are able to give answers to these questions.
It is essential for therapists to have knowledge of the results of randomized controlled trials the pharmacotherapy and the psychotherapy. Knowing the outcome of an active agent in treatments enhances physicians ability to relieve their symptoms as well as improve patients way of life as well. Harmful treatment may be administered without trials to provide efficient treatment information. Therapists will have information on treatment options or alternatives to offer patients as randomized controlled trials scientifically back their recommendations. Randomized trials help to show that therapy is better than no treatment. It is therapists ethical responsibility to inform patients of findings and treatments available.
Randomized trials reduce bias as the participants are randomly selected and do not know which group they belong to during a trial. In an experiment of mephenesin versus placebo over a four two week period, the first two weeks showed a decrease in distress following placebos in the first two weeks. A slight increase in distress occurred , statistically insignificant but the effect of placebo was great as after two weeks at the end of the eight weeks. Clinical trials enable these comparisons to be carried out to observe changes, strengths and the qualitative measure of effects of the therapy scientifically and unbiased. Validation of statistical tests of significance is...
References: Rosenthal, D, & Frank, J.D. Psychotherapy and the placebo effect. Psychological bulletin, 1956,53 : 294-300.
Diehl, H.S, Baker, A.B., & Cowan, D. W. Cold vaccines, further evaluation. Journal of American Medicine Association, 1940, 115: 593-594
Jellienker, E.M. Clinical tests on comparative effectiveness of analgesic drugs. Biometrics Bulletin, 1946, 2: 87
Wolf, S.,& Pinksy, R.H. Effects of placebo administration and occurrence of toxic reactions. Journal of American Medical Association, 1954, 155 : 339-341
Goldfried, M.R., & Wolfe. B. Psychotherapy practice and research: Repairing a strained alliance. American Psychologist, 51 : 1007-1015
Rothman, K.J., & Michels, K.B. The continuing unethical use of placebo controls. New England Journal of Medicine, 331: 394-398
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