proposed, they have yet to be proven. for instance, some scientists believe that damage to a specific region of the brain, the amygdala, may be linked to asd, while others are examining the possibility that a viral infection may trigger the disorder. there has been some controversy regarding whether vaccines can cause asd, but numerous studies have shown that there is no evidence of a link between vaccines and asd. major medical and government organizations have also confirmed this finding. the increase in asd diagnoses in recent years may be attributed to better awareness and more comprehensive definitions of the disorder. treatment for asd involves a highly structured schedule of constructive activities that build on the child's interests and various techniques. it is important to avoid unproven treatments and seek advice from asd specialists. schizophrenia large-scale famines offer insights into the effects prenatal malnutrition has on developing fetuses. a team led by dr. mingqing xu investigated this possible connection between prenatal malnutrition and schizophrenia by analyzing medical records of people born between 1960-1961 during the great chinese famine. this study found that there was a two-fold risk for someone who was born in a rural area during this period of famine to later develop schizophrenia than someone who was born either before or after. however, being born in an urban area during this time was not associated with an increased risk of schizophrenia. this is probably due to factors that exacerbated the impact of the famine in rural areas such as grain procurement and lack of large-scale grain storage. similar results have been found in studying the effects of the dutch famine from 1944-1945. a study by dr. hoek compared the levels of schizophrenia born between august 15 - december 31, 1945, to those born after than famine had ended. this study found that those born during the time period were between two and two and a half times more likely to have schizophrenia than those born after the famine had ended. the exact mechanism which connects undernutrition to an increased chance of schizophrenia later in life is not fully understood. famines may lead to an enhanced risk of schizophrenia because it deprives the developing fetus of key micronutrients. some of the leading candidates are folate, essential fatty acids, retinoids, vitamin d, and iron. of these micronutrients, folate, iron and vitamin d seem to be the most promising. folate jumps out as a key candidate as the occurrence of neural tube defects raised alongside schizophrenia during the dutch famine. a lack of folate could cause dna methylation which may affect the expression of genes crucial to neurodevelopment, and it could impede the conversion of homocysteine to methionine, causing homocysteine to accumulate and cause problems in the developing brain. iron has been put forward as a leading candidate as low levels of hemoglobin, a molecule created by iron, during development was highly associated with developing schizophrenia later on in life. this connection may be due to iron having a key role in the creation and function of dopamine transmission. another, less accepted, theory that explains the connection between famine and schizophrenia is protein-calorie malnutrition. protein-calorie malnutrition has been associated with increased dopamine and serotonin release and malfunctions in the hippocampus such as reduced dendritic branching and a lower cell count, which are also found in people with schizophrenia. maternal stress the effect stress has on expecting women may not only affect them, but their child as well. studies have shown a link between child mental health and behavioral problems to maternal stress during pregnancy. stress in the body leads to an increase in the cortisol levels. maternal stress, therefore, exposes the fetus to high cortisol levels. these levels have been linked to neurological and behavioral regulation issues in the child later in life. for example cognitive performance at 5 years of age was impaired in kids who mother had experienced stress from a catastrophic ice storm. investigators found that schizophrenia was frequent in offspring that mothers endured the ice storm during pregnancy. prenatal stress has been shown to increase reactivity in infants. infants that are from pregnancy with a lot of stress are harder to soothe rather than those that mothers didn't experience any stress during pregnancy. human and animal studies did show that infants from stressed pregnancies have a poor immune function and are more likely to contract childhood illnesses as well as mental disorders. there was a study published in the journal of pediatrics of august 19th, 2020 looked at ways of how infant health and maternal recognition of how stress can affect after or during pregnancy. the study consisted of women from low income areas, and those that were overweight which were at the age of 28 years old. the women had to rate how they felt during challenges they had to endure. the infants born during this study had to get their medical records had looked at from the first year of life their life. there was a 38 percent increase for having infectious illnesses. there was a 73 percent increase from not having non-infectious illnesses with a increase of 53 percent in other illnesses amid the infants.it seems that the effect were more prone later in the pregnancy, but after the study was completed they later realized that stress and depression in mothers is not associated with increase in illnesses amongst the infants.