A recent article in Discover links the development of schizophrenia with a human endogenous retrovirus, HERV-W. The article follows the work of E. Fuller Torrey and others in exploring a viral basis for schizophrenia.

Endogenous retroviruses are the remains of viral infections that occurred in past generations and that became encoded within the genome. In the case of HERV-W, this encoding may have taken place millions of years ago in an early primate ancestor. The HERV-W is one of several ancient viruses that have left their imprint upon the human genome.

It is currently believed that in most cases these viral remnants in our DNA are not expressed and have no effect upon humans. There is some evidence, though, that HERV-W may play a role in the development of both multiple sclerosis and schizophrenia. The suggested pathway involves early infections that trigger the virus, leading to an immune reaction that damages our nervous system and that can eventually cause either of these conditions. Later infections may also play a role.

This is a line of research that could offer future ways of helping to prevent or to treat schizophrenia. As such it is an important endeavour. However, it is a common error to argue for a single cause for a complex, multi-factorial process. The Discover article falls into that trap, as shown by its title: ‘The Insanity Virus’. Even if the theories of Torrey and others prove to be correct, what they give us is a description of one factor in the development of schizophrenia. Other factors, including the individual’s environment, are also likely to play a role. The suggested pathway involves the human immune system, which has been shown to be heavily influenced by psychological factors such as stress. For that reason our early emotional life may play a crucial role in the development of schizophrenia, even within the causal model proposed by Torrey.

Torrey and other writers looking for a purely biological explanation for mental disorders discount the importance of the infant’s early experience of their world. This ignores the intimate ways in which our mind and body interact and effect each other’s development. It is an approach to human beings that is as one sided as the purely psychological. It is also a view that ignores the healing potential of therapeutic relationships.