What is the Mood Disorder Appraisal (MDA)?

The Bio Concepts Mood Disorder Appraisal (MDA) assists you with determining potential chemical imbalances in your patients. It is designed as a tool to help practitioners identify which neurotransmitter pathways may benefit from support, through a simple questionnaire which can be emailed directly to the patient. This allows the patient to complete the questions in their own time.

The 66 multiple choice questions take around 15-30 minutes to answer. Once completed, patients can simply click 'submit' and the appraisal results will be emailed immediately to the practitioner for interpretation.

The results are displayed in a colour coded bar graph which highlights potential deficiencies from most to least deficient. This graph simplifies the identification of pathways and nutrients required to support these pathways. The patient's responses are included below the analysis and recommendations, and can offer additional insights for the case.

The questions in the MDA screen a patient’s health status, particularly focussed on mood, behaviours, stress and neurotransmitter balance. This format can support your consultation flow, preparation and prescription, and the MDA can be completed either in clinic or sent directly to patients to complete at home. This tool is available to all registered practitioners for free.






How was the MDA developed?

The Mood Disorder Appraisal (MDA) was first developed in 2004 by Bio Concepts staff in conjunction with a statistician attached to the QUT School of Mathematical Sciences. The questions were developed by assessing the available scientific literature to ascertain the core signs and symptoms associated with neurotransmitter deficiencies with only high quality human studies included.

Empirical data formed the basis for the MDA question development with updates occurring alongside with advancements in the research. The signs and symptoms of each deficiency are given weighting as to how probable a person with that deficiency is to manifest particular symptoms.

Validity of the MDA

The MDA is a questionnaire, so it is very subjective and, as such, can have issues with both reliability and validity. It is not a validated tool. The MDA is, however, a generally reliable clinical assessment and demonstrates that people with similar symptom pictures tend to present with the same deficiencies, even when symptoms can be caused by several neurotransmitters.

When first launched, a number of tests were done to compare the deficiencies identified in the MDA with pathology, ie. neuroendocrine metabolites and blood histamine levels. The results did coincide and the neurotransmitters that were found to be deficient, were measurably deficient.

Additionally, the use of nutritional and herbal medicine to positively influence specific neurotransmitter levels, when prescribed using the MDA, frequently result in improved symptom pictures.


How to access the MDA


Log into


Select your name in the top right hand corner


Click 'Manage Patients' and then select 'New patient + Appraisal'

Key features


Colour-coded & easy-to-read results format


Patient-friendly language inclusions


Additional practitioner information & learning tools


How to set up your patients

This short video offers a guide on how to set up your patients to use the MDA.





How to interpret the MDA

This in-depth video is a guide for interpreting the results of the MDA after your patient has completed the appraisal.




Related Resource

The revamped Neurotransmitter Chart can be used in conjunction with the Mood Disorder Appraisal to assist with interpretation of results.

Download pdf

My patient is already registered under another practitioner. How can I set them up as a patient with myself?

You can try setting up your patient using an alternative email address or if this is not possible please ask your patient to email our very helpful Customer Service Team requesting to be deactivated from their pre-existing practitioner's account:

Is the questionnaire validated?

The MDA is subjective and not a validated tool. There are other tests available which work well in conjunction with the MDA. Consider an amino acid profile, neuroendocrine metabolite profile and histamine testing.

Why are questions repetitive?

Questions are carefully designed to ask questions in different ways so that one or all may apply to your patient.

Can the MDA be adapted for children?

The level of neurotransmitters in the brains of children differ greatly to those in adults. We would not recommend that the MDA be used on children to assess their neurotransmitter balance.

The results indicate that the patient’s neurotransmitters are all deficient. How do I treat the patient?

This suggests that the patient’s problem may be due to insufficient gastric function or poor protein (amino acid) intake or assimilation. A faulty digestive process can result in the malabsorption of key nutrients essential for maintaining healthy mood patterns and overall feeling of well-being. Amino acids are the building blocks of protein and are crucial to the production of important brain neurotransmitters. Poor protein status and inefficient digestive function may be the underlying cause to many mood disorders and it would be wise to assess both digestive function and protein intake in conjunction with their presenting signs and symptoms as part of the initial treatment. 

My patient presents with poor sleep; however, their MDA results indicate they are not deficient in serotonin or melatonin. How do I treat their insomnia?

Understanding the biochemistry of sleep is the important factor when addressing insomnia. Melatonin is indeed one of the main neurotransmitters involved in the sleep cycle, however it is important to assess if the patient has trouble initiating sleep or maintaining sleep. Adenosine may be indicated in assisting the patient to initiate sleep as it is an inhibitory neuromodulator and increases the urge to sleep. It is also important to address GABA status as GABA has also been shown to reduce the firing of neurotransmitters involved in wakefulness (histamine, norepinephrine, serotonin, hypocretin and glutamate) by neurons. Other factors which may disturb their circadian balance such as a diet rich in tyramine containing foods, increased stimulant use, poor lifestyle habits (ie smoking, alcohol or recreational drug use) poor sleeping position, poor sleep hygiene (phones, screens, working), irregular sleeping times (shift work), inflammatory or acidic conditions and stress may also interfere with sleep patterns. 

How often is it recommended the patient repeat the MDA?

We recommend no less than six weeks between the initial MDA and a follow up. The MDA will provide the option to chart their progress between appraisals. Once the patient has stabilised, completing the questionnaire every six months should be sufficient.


How are serotonin and melatonin related?

Serotonin is the immediate precursor to melatonin. It involves a methyl-dependent enzyme reaction for this conversion. If the patient has adequate serotonin, but not enough melatonin and is complaining of poor sleep, it may indicate that they require more methyl donating nutrients such as SAMe or methionine to up-regulate this conversion. 

Why is my patient’s iron status important to their neurotransmitter balance?

Iron is an important cofactor for many functions within the body. The mechanism by which iron deficiency may affect mental health is unknown, however iron has important roles in the functioning of several neurotransmitters, including dopamine, serotonin and catecholamines. Iron is a co-factor for tyrosine hydroxylase, tryptophan hydroxylase, xanthine oxidase and ribonucleoside reductase. Thus, one would expect that a deficiency in iron would lead to decreased activity of these enzymes.

If you still have any questions about how to use the mood disorder appraisal, please feel free to send your questions to our Education Centre team at