<unk>  include many genetic and environmental phenomena. The prevailing model of<unk>  is that of a special neurodevelopmental disorder with no precise boundary or single cause (i.e. arises from multiple mechanisms).<unk>  is thought to develop from very complex gene–environment interactions with vulnerability<unk> . The interactions of these<unk><unk>  are intricate, as numerous and diverse medical insults from conception to adulthood can be involved. The combination of genetic and environmental<unk>  leads to deficits in the neural circuits that affect sensory input and cognitive functions. Historically, this theory has been broadly accepted but impossible to prove given ethical limitations. The first definitive proof that<unk>  arises from multiple biological changes in the brain was recently established in human tissue grown from patient stem cells, where the complexity of disease was found to be "even more complex than currently accepted" due to cell-by-cell encoding of<unk> -related neuropathology. A genetic predisposition on its own, without superimposed environmental<unk><unk> , generally does not give rise to<unk> . Environmental<unk><unk>  are many, and include pregnancy complications, prenatal stress and nutrition, and adverse childhood experiences. An environmental<unk> <unk> may act alone or in combination with others.<unk>  typically develops between the ages of 16–30 (generally males aged 16–25 years and females 25–30 years); about 75 percent of people living with the illness developed it in these age-ranges. Childhood<unk>  (very early onset<unk>  develops before the age of 13 years and is quite rare. On average there is a somewhat earlier onset for men than women, with the possible influence of the female sex hormone estrogen being one hypothesis and socio-cultural influences another. Estrogen seems to have a dampening effect on dopamine receptors.
Risk factors of schizophrenia
Sex differences in schizophrenia
Comparison of bipolar disorder and schizophrenia
Long-term depression
Biology of depression
Prognosis of schizophrenia
types of Mood disorder
Causes and origins of Tourette syndrome