Increased breath ethane and pentane concentrations in currently unmedicated patients with schizophrenia

Schizophrenia is a common and debilitating mental illness. The disorder is thought to be developmental in origin, with oxidative stress being implicated as possible pathophysiological mechanism. Breath alkanes provide a non-invasive means to assess oxidative stress, with ethane levels reportedly increased in medicated patients with schizophrenia. It is possible, however, that the psychotropic medications used to treat the disorder result in elevated breath ethane levels. We have therefore measured the concentration of ethane and pentane, markers of oxidative stress, in the breath of currently unmedicated patients with schizophrenia. Alveolar breath samples were collected, applied to thermal desorption tubes, and analyzed using a combination of two-stage thermal desorption, gas chromatography and mass spectrometry. Compared to healthy controls ethane and pentane levels were found to be elevated in patients with schizophrenia, while levels of butane were normal. Our data support the notion that oxidative stress is increased in schizophrenia and that this is unlikely to be a consequence of antipsychotic medications. In addition, breath alkane analysis may represent a rapid and non-invasive means to monitor oxidative stress occurring in schizophrenia.