There is no single deficiency that causes schizophrenia. Schizophrenia is a complex mental disorder that is believed to be caused by a combination of genetic, environmental, and neurobiological factors.
Genetic factors are thought to play a role in the development of schizophrenia, as the disorder tends to run in families. However, no specific gene has been identified as the sole cause of schizophrenia, and it is believed that multiple genes may interact with environmental factors to increase the risk of developing the disorder.
Environmental factors that have been associated with an increased risk of developing schizophrenia include exposure to viral infections, prenatal stress or malnutrition, and early childhood trauma or abuse.
Neurobiological factors that have been implicated in schizophrenia include imbalances in neurotransmitters such as dopamine and glutamate, as well as structural and functional abnormalities in brain regions involved in cognition and emotion regulation.
Overall, while there is no single deficiency that causes schizophrenia, the disorder is believed to result from a complex interplay of genetic, environmental, and neurobiological factors.