Something sad and a piece of evidence about the genetic link to schizophrenia

From
http://schizophreniabulletin.oxfordjournals.org/cgi/reprint/2/3/360.pdf
A critical review of recent adoption, twin, and family studies of schizophrenia: Behavioral genetics perspectives
II Gottesman, J Shields - Schizophrenia Bulletin, 1976

This is from a long paper critically assessing the evidence from 30 years ago. It notes the twin studies at the time may have been methodologically flawed. The main criticism of this sort of basic genetics research is that it can't differentiate between the complex effects of environment and genes with suitable rigour such that it can't be criticised. At the moment I'm looking for an adopted twin study. This should be a powerful instrument to separate out as many of the environmental factors as possible.

Here's the interesting and saddening text
"
It was against this background that Heston (1966)
reported a higher prevalence of schizophrenia and other
disorders in the children borne by hospitalized, chronic
schizophrenic mothers, separated from them within the
first 3 days of life, and reared in institutions or foster
homes without contact with their mothers or their
mothers' families. There was no schizophrenia and
significantly less other psychopathology in a control
group with nonpsychotic parentage and matched for
type of rearing. Heston's study was followed by the
elegantly designed adoption studies from Denmark
(Kety et al. 1968 and Rosenthal et al. 1968), in which
every effort was made to eliminate the possibility that
knowledge of the diagnosis of one family member might
influence the diagnosis of another (contaminated
diagnosis).
"

It's sad what happens to people.