It's a scary thought that one could develop a debilitating mental illness such as schizophrenia as easily as catching a cold. Well, it's more complicated than that, say advocates of the so-called infectious hypothesis, which states that viral and possibly bacterial infections occurring at critical points in brain development could increase the risk of mental illness. Everything from influenza to herpes simplex viruses to Toxoplasma gondii has been implicated in elevating risk for schizophrenia, perhaps indirectly through immunological reactions that change brain chemistry or wiring at key developmental stages. Raised, ridiculed, retracted, and rewrought, the hypothesis has morphed for nearly a century.
Its current permutation may be gaining ground, though. With better epidemiological studies and animal work emerging, some former scoffers are beginning to accept the notion that, while not a direct cause, infections may factor into schizophrenia's complex gene/environment formula that dictates one's chances for landing somewhere among the ...
