Due to intense ATP-consuming processes in the brain, a high level of brain energy supply is required. A popular hypothesis regarding the pathogenesis and pathophysiology of schizophrenia postulates hypofunction of neuronal circuits in the prefrontal and limbic-temporal areas. An emerging body of data suggests that impaired energy metabolism due to mitochondrial dysfunction plays a role in the pathophysiology of schizophrenia.

Under normal conditions cellular metabolic rate, i.e. oxygen and glucose consumption, increases proportionally with any increase in neuronal activity. The impaired energy metabolism due to mitochondrial dysfunction and frontal lobe hypofunction might be improved by increasing O2 supply to the brain. Oxygen-enriched air inhalation has been shown to increase brain oxygen supply. Hyperoxia therapy is a useful tool in the treatment of neurological and neurotrauma deficits.

We therefore suggest a randomized double blind cross-over study of enriched inspired O2 partial pressure in schizophrenia.

It is surprising given the numerous findings on reduced energy metabolism in schizophrenia that simple treatment with inspired enriched oxygen has not been studied.

Inclusion Criteria:

• 18-45 years old
• 2 years of illness
• PANSS more than 60

Exclusion Criteria:

• unstable or serious physical illness
• suicidality
• drug abuse
• BMI above 30
• taking anti-hypertension medication