What Causes MND?

What causes MND is the biggest and possibly the most frequently asked question by researchers.

Most cases of MND occur for no apparent reason, in people without a family history of the disease. This is known as sporadic MND. In about 5–10% of cases however, family history of the disease indicates that inherited gene mutations cause the condition. This is called familial MND.


There are many theories about the causes of MND. These include exposure to environmental toxins and chemicals, infection by viral agents, immune-mediated damage, premature aging of motor neurons, loss of growth factors required to maintain motor neuron survival and genetic susceptibility.

Scientists believe that the randomly occurring sporadic form of MND is likely to be caused by many small contributory risk factors, including subtle genetic and environmental influences, that in combination may 'tip the balance' towards someone developing the disease.

Exposure to environmental factors that might contribute to the development of sporadic MND has been widely studied. Studies have identified possible links with prior exposure to agricultural chemicals and a variety of heavy metals, high levels of exercise and exposure to mechanical and/or electrical trauma. However, the evidence obtained in these studies has often not been convincing and there are no clear conclusions at this time.

“The evidence that exposure to pesticides is a contributory risk factor towards getting MND is stacking up and I’m sure will be the focus of future research," said Dr Belinda Cupid, Head of Research at the UK MND Association, in May 2016.

New Zealanders with MND can participate in the Massey University Research Study looking at risk factors for MND in New Zealand (see below).

Researchers worldwide continue to try and find out what causes MND with the ultimate goal of discovering how to stop, slow down or prevent the disease.

It is not yet possible to provide advice on how to reduce the risk of developing MND.

MND NZ is supporting a New Zealand research study on MND, titled Occupation and Environmental Risk Factors for MND. The study is being conducted by the Centre for Public Health Research at Massey University in Wellington.

Very little is known about the causes of MND and the study aims to investigate the relationship between MND in New Zealand and a range of known or suspected occupational and environmental exposures.

Preliminary results indicate elevated risks for those working in agriculture (in particular horticulture and fruit growing), construction, automotive fuel retailing and computer services.

The study requires a further 30 participants. If you have MND and you are interested in taking part in the study then please contact:

Grace Chen
Email: g.chen1@massey.ac.nz
Freephone: 0800 793 121

Your participation in the research requires a face-to-face or telephone interview with a trained research nurse, or the completion of a postal questionnaire by you.

Click here for more information about the Massey University MND research study.

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