The Effects of 12 Weeks Supplementation With a B-vitamin and Herbal Supplement on Neurocognitive Function and Mood

Participants respond with a right button press to the appearance of a single white square at the centre of the screen. Thirty targets are presented with a randomized inter-stimulus interval (ISI) to avoid anticipation effects.

Participants respond with a left (blue) or right (red) button press to the appearance of a blue triangle or red square respectively. Presentation order and ISI are randomized to avoid anticipation effects.

Participants are asked to study a series of 40 abstract images presented serially in the centre of the screen for 3-seconds each with no ISI. On completion, another series of images are presented, half of which were from the studied series and half that are new (Immediate condition). Participants indicate with a right (yes) or left (no) button press whether or not they recognized the image from the studied series. This task is repeated at the end of the testing session with the remaining 20 images from the studied series and another 20 new images (Delayed condition).

he test consists of two congruent and two incongruent trials, presented alternately. Stimulus words are randomly presented (RED, BLUE, GREEN, YELLOW) in either congruent or incongruent colours for 1.7-seconds, with an ISI of 0.5-seconds. Participants responded by pressing one of four buttons corresponding to the colour of the word, irrespective of what the word read. This task is used as a measure of executive function and more specifically inhibition; participants have to inhibit the automatic reading response.

A series of 20 everyday images are presented at the top/bottom/left/right of the screen for 3-seconds each with no ISI. On completion of the series the same images are displayed again in randomized order in the centre of the screen for 2-seconds each with no ISI. Participantsrespond with a top/bottom/left/right button press to indicate the original location of each image. The task requires participants to recall the spatial context of the original presentation and was used as a measure of episodic memory.

The participant is required to count backwards in threes from a random starting number between 800 and 999. The starting number is presented on the computer screen, and then is cleared by the first response. Participants are instructed to respond as quickly and as accurately as possible using computer keyboard keys. The participant completes the task over a period of two minutes.

The participant is required to count backwards in sevens from a random starting number between 800 and 999. The starting number is presented on the computer screen, and then is cleared by the first response. Participants are instructed to respond as quickly and as accurately as possible using computer keyboard keys. The participant completes the task over a period of two minutes.

A series of digits are presented in the centre of the screen at the rate of 100 per minute. The participant is required to detect three consecutive ascending odd or three consecutive ascending even digits. The participant responds to the detection of a target string by pressing the 'space bar'. The task is continuous for five minutes, with eight target strings presented each minute. This task is used as a measure of processing speed.

The PSS measures the extent to which respondents have perceived events in their life as stressful over the last month. There are 14 items, each scored on a 5-point scale ranging from 'never' to 'very often'. Seven of these items are positively stated items, and therefore they are reverse scored. Higher scores on the PSS are associated with higher levels of perceived stress.

The POMS requires participants to indicate the degree to which they have identified with 65 mood-related adjectives over the past week. Each item is on a 5-point scale from 'not at all' to 'extremely'. Items are summed into six factors; Tensio n-Anxiety, Confusion-Bewilderment, Anger-Hostilit y, Depressio n-Dejection, Fatigue-Inertia and Vigor-Activit y.A Total Mood Disturbance (TMD) score is computed as the sum of the first 5 factors minus Vigor-Activity. High scores indicate greater mood disturbance on all scales except Vigor-Activity.

The DASS measures comprises of 21 items that pertain to affect- related symptoms for three sub-factors: depression, anxiety and stress. Participants must respond to each item to reflect their experiences over the past week. Each item is on a 4-point scale fro m 0 to 3, with a total range of scores from 0 to 63. Higher scores indicate a higher degree of dysfunction and less desirable affect experience. A score of zero does not indicate positive mood, but rather the lack of presence of negative mood state symptoms. The DASS is considered relevant for both clinical and non-clinical populations as some experience of such symptoms is considered normal in day to day life.

The State-Trait Anxiety Inventory (STAI) contains two subscales; one that measures the transient experiences of anxiety (STAI-S) and the other measures the more stable personality characteristic (STAI-T). The state subscale (STAI-S) contains 20 items, asking participants about to respond with how they are feeling 'right now', ranging from 'not at all' to 'very much so'. The total range of scores is from 20 to 80, with higher scores indicating higher levels of anxiety.

This task comprises of 16 100mm lines anchored at either end by antonyms. Participants must mark their current subjective state between the antonyms on each line, bearing in mind that each end of the scale represents an extreme. Each line is scored as millimetres to the mark from the negative antonym. From the scores, a factor analysis can isolate three factors; 'alertness', 'calmness' and 'contentedness'. Scores for each factor represent the unweighted average number of millimetres from the negative antonym for the individual scales contributing to the factor.

The following scales will ask the participant to rate their subjective experiences of stress, fatigue, concentration and stamina in the present moment. In each case, participants will rate their subjective feeling on a 100mm visual analogue scale, and be required to mark the line as a response to reflect their current subjective state: Stress, anxiety, mental fatigue, concentration, mental stamina.

The PRMQ is a self-rated measure of prospective and retrospective memory slips in everyday life. It consists of sixteen statements, half which relate to prospective memory failures, and the other half relate to retrospective failures. The participant must respond with how often each statement applies to them. Items are scored in a likert format with response options from 'very often' to 'never'.

The CFS is a self-rated measure of fatigue severity over the past week. The scale consists of 14 items, eight relating to physical symptoms and six questions relating to mental fat igue. Items are scored in a likert format with response options ranging from 'better than usual' to 'much worse than usual'.

At the end of the study, participants will be asked the following qualitative questions: 1.While taking part in this study, have you experienced any positive changes in your physical or mental health (mood, stress, brain function) that you don't know the cause of or you think may be caused by the study tablets? 2.While taking part in this study, have you experienced any negative changes in your physical or mental health (mood, stress, brain function) that you don't know the cause of or you think may be caused by the study tablets? 3.While taking part in this study have you experienced any unusual changes (not necessarily good or bad) in your physical or mental health (mood, stress, brain function) that you don't know the cause of or you think may be caused by the study tablets? These questions are designed to capture any additional changes to cognition or mood that may not be picked up using the other questionnaires.

Participants will have fasting blood samples taken at the participant's baseline (V1) visit and their final (V2) visit. Blood samples will be collected by a qualified venepuncture technician or research nurse at the Centre for Human Psychopharmacology and securely stored in a freezer. All blood samples (with the exception of blood for essential fatty acid panel analysis) will sent to an Australian Clinical Labs pathology lab in Melbourne to be analysed. Samples used for essential fatty acid panel analysis will be sent to the University of Adelaide pathology lab to be analysed.

Samples will be tested for: Vitamin B1, B2, B6, B12, Red Cell Folate and Homocysteine, high-sensitivity C-reactive protein, electrolytes, renal function, liver function and cholesterol.

A medical investigator will assess the clinical significance of any abnormal values.

Participants who are consented for additional neuroimaging will undergo the following: functional magnetic resonance imaging, arterial spin labelling and diffusion tensor imaging.