Obstetrical and birth complications
The ways in which birth complications double the risk for schizophrenia are not known. But several studies show that various obstetrical and birth complications do increase risk.
A statistical review of multiple studies looking at the link between obstetric complications and schizophrenia found three groups of complications associated with the disorder:
· Complications of pregnancy, including bleeding, diabetes, Rh incompatibility, and pregnancy-induced high blood pressure
· Abnormal fetal growth and development, including low birth weight, cardiovascular congenital anomalies, and small head circumference
· Complications of delivery, including lack of uterine muscle tone, inadequate oxygen intake by the baby, and emergency cesarean section (C-section)
· Other life experiences
Although parents have been let off the hook as far as finger-pointing blame for schizophrenia goes, the current consensus is that other environmental stressors and stress in general may contribute to the onset of schizophrenia. For example, urban life, geographic migration, and poverty are all associated with increased rates of schizophrenia.
Other studies have shown that individuals with schizophrenia smoke marijuana more often than the general population. Some prospective studies now show that smoking marijuana (before the onset of psychotic symptoms) increases the likelihood of schizophrenia by two to four times. On the other hand, the overwhelming majority of people who smoke marijuana don’t develop schizophrenia.