The Effects of a Single Dose of Methylphenidate on Motor Performance

The Effects of a Single Dose of Methylphenidate on Motor Performance

Aim: To evaluate the effects of MPH on young adults diagnosed with ADHD on different exercise performance tests.

Hypothesis: MPH will have positive effects on motor tests requiring concentration.

Methods: 200 healthy physical education students, 100 participants diagnosed with ADHD will serve as the treatment group and 100 non-ADHD diagnosed will serve as a control group. The study will be divided into two sub studies (100 participants each), in which, two motor tests will be evaluated (two agility tests, two motor accuracy tests and balance).

All participants will arrive for two sessions, and will perform two motor tests in each session. In the second session, half of the participants with ADHD (25 participants) will undergo another session of the same motor tests with their usual treatment (treatment group) and another half (25 participants) without their treatment (ADHD control group). The non-ADHD control group (50 participants) will perform the second session without medications - to assess a learning effect.

Note, the investigators are not planning on giving the medication to the participant, rather he/she will consume their own prescribed MPH by them self. Control treatment for ADHD participants will consist of not taking their medication before the motor test.

For evaluation of physiological responses and perception of effort, heart rate, temperature, blood pressure and RPE before and after motor tests, will be measured.

200 healthy physical education students and Mechina from the Academic College at Wingate, males and females, will be recruited to the study. 100 participants diagnosed with ADHD will serve as the treatment group and 100 non-ADHD diagnosed will serve as a control group.

Recruitment procedure will consist of emails to all students in college or by entering classes or zoom meetings. Volunteers answering the mail or providing their contact details will be regarded as giving consent to be addressed by the research assistant by a phone call. A research assistant will call volunteers and will briefly explain the study procedures and invite them to the first session in which they will sign an informed consent form approved by the institutional review board (Helsinki). Next, all participants will fill a general background questionnaire and an ADHD self-report scale questionnaire.

The second and third sessions will consist of motor tests, at least one week apart. In one of the sessions, ADHD volunteers will kindly be asked to arrive to the session before they took their stimulant medication or to come to the session after consuming their usual treatment (1 hour before the session begins). The order of sessions with or without treatment will be randomly decided. The investigators point out that the patient takes his own treatment himself when assigned to the ADHD treatment group. The non-ADHD control group (50 participants) will perform the two sessions without medications - to assess a learning effect.

The background questionnaire consists of general information relevant for the study. This includes name, gender, anthropometrical characteristics, chronic illness, regular medication consumption, etc. In addition, the participant will answer questions regarding diagnosis of ADHD, MPH consumption and physical activity participation.

The participants will fill the Adult ADHD Self Report Screen (ASRS) in Hebrew. This form was shown to be valid, reliable and had good internal consistence. This screen will be used for correlation analysis oh ADHD severity and exercise performance. The form is attached in this proposal.

The treatment will include taking the patient's own medication by the patient himself in the treatment session 60-180 minutes before the beginning of the tests, according to their prescription given by their own physician. Participants must have consumed this medication at least 3 months before the first session as their regular treatment for ADHD. Note, the investigators are not planning on giving the medication to the participant, rather he/she will consume their own prescribed MPH by them self.

Control treatment for ADHD participants will consist of not taking their medication before the motor test. Since there may be participant who needs to take the medication every day, they will be instructed to consume their medication at the end of the session. In this case, session meeting will be performed at morning time.

Motor tests Balance test One-leg blind balance test will be performed. The maximum number of seconds a participant is able to stand without toppling or putting a foot down will be noted. Participants will stand on both legs with eyes open, facing forward, and then lift one leg with eyes closed, facing forward on a marked site. Time recording will be stopped when participants will begin to teeter; put the foot on the floor or open their eyes. Two attempts (one for each leg) will be made, and the higher value of these two attempts will be used.

Agility tests Two agility tests will be performed twice, the best time of each test will be recorded. Calculation of the ratio of zigzag test without the ball and with the ball will be conducted on a sports hall. These two agility tests were evaluated and validated elsewhere.

Zigzag test- Running agility test. Participant is required to run a course in the shortest possible time A zigzag course consists of a rectangle 3 X 5 meters set out at 100º angles by four cones placed on the corners, with one more cone placed in the center (Fig 1). Overall there are 6 segments numbered from 1-6 according to their order in the test. This test measures rapid acceleration, deceleration and balance control

Fig 1. Schematic representation of the Zigzag Test. Noted the start and stop points. The pathways are indicated as arrows and are numbered according to their order in the test. Triangles indicates cones.

Zigzag with a ball- The same as the former test (fig 1), but with a ball. Participants will be instructed to run as fast as possible with the ball. This test measures rapid acceleration, deceleration and balance control as well as controlling the ball.

Accuracy motor tests The stationary free throw shooting test- Each participant will perform three series of ten free-throw shots (two throws in five different positions) with a 3-minute rest period between the series. Two participants will be positioned below the hoop and they will pass the ball to the testee. After the participant completes ten shots, another participant will come to the free throw line and will perform the same task. The average scores of the all three trials will be used for analysis.

Fig 2. Schematic representation of the stationary free throw shooting test. Arrows indicate shooting positions. Order of the throwing positions are numbered.

The dynamic 60-second free throw shooting test- For easier organization of the testing a volleyball court will be used as illustrated in Figure 1. Each participant will perform five series of two free throws with sprinting between the series. Each series will be completed in 12 seconds. Each participant will start the test with an 18-meter sprint (volleyball court sideline), then will turn around a cone and run to the free throw line. After performing two free throws the participant will run to another cone where he will wait for a sound signal to start the next series. One tester will use a stopwatch to measure 12 seconds, and to give a signal to the participant. Another tester will count the number of free throws made. Two other participants will pass the balls to the testee. The participants will perform the three dynamic tests with a five-minute recovery between each. The average scores of all three trials will be used for analysis.

Fig 2. The dynamic 60-second free throw shooting test.

Measurements Blood pressure- blood pressure will be measured at the beginning of each session. Peak BP will be measured at the end of the last motor test at each session. BP will be measured by using a mercury sphygmomanometer.

Body temperature- body temperature will be measured sublingually at the beginning of each session. Peak BP will be measured at the end of the last motor test at each session. Temperature will be measured by using an electronic thermometer.

Heart rate- resting heart rates will be recorded at the beginning of each session, and at the end of the last motor test. HR will be measured by a polar watch (Polar heart rate monitor S 710).

RPE scale- To measure subjective sense of effort the Borg rate of perceived exertion (RPE) scale (ranges from 6 to 20) will be used at the end of the last motor test at each session.

Inclusion Criteria:

Students age 18-45 years old studying at the academic college at Wingate. For the treatment group we will recruit students who were previously diagnosed by a neurologist or psychiatrist or other ADHD physician specialist as having ADHD, and are treated with a methylphenidate (Ritalin; Ritalin SR; Ritalin LA; Concerta) at least 3 months before the first session. Control group will consist of students without ADHD.

Exclusion Criteria:

any chronic illness other than ADHD (e.g. asthma, gastrointestinal, depression, anxiety, etc.), taking chronic medications apart from stimulant therapy.