A recent study draws a clear developmental link between autism and schizophrenia, suggesting that the same inborn irregularities in early fetal development may be responsible for these and other neurological disorders.

A series of unrelated experiments concerning the regulatory functions of fruit flies revealed that certain mutations to a receptor for glutamate, an amino acid substance found in most of our foods that plays an active role in various internal regulatory processes, prevents the neuro-regulator enzyme phosphoinositide 3-kinase (PI3K) from working properly. In its standard capacity, this enzyme controls the excitability levels of all passing neurons. If the enzyme cannot do its job, the movement of various neurons cannot be effectively controlled – and chronic irregularities (most often disorders like neurofibromatosis, a genetic condition in which neural endings spawn small tumors) result.

The study grew more significant as researchers realized that the same receptor mutations occur in humans. Glutamate, which is consumed and released by the body according to a level of need determined by the supervisory neurons, feeds back on itself when its receptors don’t work properly. The body, unable to properly process the glutamate it needs, ultimately produces less of this crucial substance, and its internal balance suffers. A developing brain affected by such mutations will develop in irregular ways from the start. The prime symptom of this mutation is a chain of extremely excitable neurons that grow overactive because they cannot perform their duties properly. A list of chronic mental health problems caused by neuronal “excitability” includes autism, schizophrenia and epilepsy.  

The most interesting element of this (very technical) report is the fact that the same mutations can be observed in all these chronic disorder. What does it mean to the layman whose grasp of the related bodily functions and chemicals is, at best, tentative? It means that, in many or even most cases, autism and schizophrenia share a developmental root – the chain of events that creates these disorders begins with a slight genetic irregularity that may be an evolutionary accident but is clearly present from birth. A simultaneous and very different study came to a similar conclusion, noting that many of the physical irregularities (protruding ears, large heads, misshapen toes) common to autistic individuals also occur in schizophrenics and theorizing that the cause of these shared mutations is a single genetic deformity.

This conclusion is unlikely to bring comfort to those hoping for some kind of treatment to reverse the symptoms of these conditions. But it certainly serves to make the experience more universal. These divergent disorders, each with its own set of personal and medical trauma, are not so different. They may, in fact, spring from the same microscopic imperfection. And the more we learn about their roots, the closer we come to more effective forms of treatment.