euro-cognitive effects of tyrosine supplementation in older adults

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 28

Inclusion Criteria

Inclusion criteria (zie sectie 4.2 op pagina 12 van het protocol)
In order to be eligible to participate in this study, subjects must meet all of these criteria:
- Age: 60-75 years old
- Proficient knowledge of the Dutch language
- Right-handed
- Willing to perform tasks in the MRI scanner, to come to the centre on three occasions, consuming tyrosine or a placebo and willing to fast the night before the two test sessions.

Exclusion Criteria

Exclusion criteria (see section 4.3 on page 12 of the protocol)
A potential subject who meets any of the following criteria will be excluded from participation in this study (for a checklist see F1 Intake Questionnaires and Checklists):
- Mini Mental State Examination score < 24
- HADS score > 11
- Estimated IQ < 85 (based on Nederlandse Leestest voor Volwassenen (NLV) -score)
- (History of) clinically significant psychiatric disorder
- (History of) clinically significant neurological disorder, such as brain infarct, Parkinson*s Disease, chronic migraine, Diabetes Mellitus
- First degree family history of schizophrenia, bipolar disorder or major depressive disorder
- Thyroid problems and low-protein diet
- Daily use of beta blockers
- Using medication that can interfere with tyrosine*s action; monoamine oxidase inhibitors and other antidepressants, sympathomimetic amines, and opioids
- General medical conditions, such as repetitive strain injury (RSI) or sensori-motor handicaps, blindness or colorblindness, as judged by the investigator
- (History of) abuse of drugs or alcohol
- Habitual smoking, i.e. more than a pack of cigarettes per week
- Participation, current or within the past twelve months, in a specific cognitive training study
- Contra-indications for MRI:
o Metal objects or fragments in the body that cannot be taken out
o Active implants in the body
o Using medical plasters
o Epilepsy
o Previous head surgery
o Claustrophobia

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>We will assess the effect of the intervention on BOLD signal measured with<br /><br>functional magnetic resonance imaging (fMRI) and response times and accuracy on<br /><br>the computerized tasks during fMRI. </p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Secondarily, effects on paper and pencil neuropsychological tasks will be<br /><br>assessed. Also, intervention effects on subjective measurements (e.g.<br /><br>self-report questionnaires, visual analogue scales), on catecholamine and<br /><br>serotonin metabolites (MVA - metanefrine, HVA - normetinefrine, HVA - 3-MT and<br /><br>5-HIAA) in urine samples, and on physiological recordings (blood pressure,<br /><br>heart rate) will be measured. </p><br>