Developmental Disorder

Despite numerous well conducted studies associating congenital or neonatal infections to schizophrenia, the infection hypothesis remains compelling but has yet to be proven. Perhaps most annoying to both critics and proposers of the infection hypotheses is the differentiality between studies performed and the failure to identify a specific infection as being consistently associated with all or most cases of the disease.

The developmental theories of schizophrenia say that basically something goes wrong when the brain is developing. Brain development, from the beginning stage of fetal development through the early years of life, is an incredibly complicated process. During this time, millions upon millions of neurons are formed, travel to different regions of the forming brain, and specialize to perform different functions.

The “something” that goes wrong might be an infection, a nutritional stress, a hormonal imbalance, an error in genetic encoding, or something else entirely. The common element in all developmental theories is that the event that causes schizophrenia occurs during the brain’s development.

 

Symptoms of schizophrenia usually emerge in late adolescence or early adulthood. Developmental theories suggest an early mutation or interruption causes the brain structure to be disordered. The start of puberty brings a number of neurological events, including the programmed death of many brain cells, and at that time the abnormalities become critical.

There are a number of risk factors for schizophrenia related to critical periods in fetal development, that support the developmental theories such as:

          
           Mothers who experienced famine during the first trimester are more likely to have children that develop schizophrenia.

                Pregnancy and birth complications increase the risk of developing schizophrenia.

Although the studies are compelling and risk factors point to developmental theories, there is not yet enough evidence that the brains of adults with schizophrenia are disorganized in the ways that developmental theories suggest. Also, these theories address the When of schizophrenia’s origin, but not the cause itself.

References:

http://apt.rcpsych.org/content/13/5/384.full

http://mentalhealth.about.com/od/schizophrenia/a/sz2.htm