What causes schizophrenia?
In simple terms, schizophrenia is commonly recognized to be caused by interactions between stressors in someone’s environment, both social and biological, and the combined disruption of various genes in their genome1.
As experiences and genetics differ for different people, learning the root causes can be found by answering these questions:
- Which genetic and environmental factors are involved?
- How do these factors act and interact?
- As scientists start to get answers to these questions, how can we apply this knowledge to find better treatments for people with the illness?
Further and ongoing Schizophrenia research is crucial though; this is a complex disease with complex causes, stressors, and symptoms.
Which genetic and environmental factors are involved?
When certain genes experience a disruption in their coding due to a mutation in someone’s genetic lineage, these mutations tend to lead to the development of Schizophrenia. Many of these specific genes have already been identified by correlating DNA sequences with the presence of the disease within affected family members under medical study. DISC1 and NRG1 are two common genes to experience coding disruptions and influence the development of Schizophrenia.
With the recent advent of genome sequencing, over 100 rare variations have been found through statistical genome-wide association studies involving tens of thousands of volunteer subjects.
As of now, it has become apparent that hundreds – or even thousands – of genes may play a contributing role to increasing one’s small statistical risk to develop the illness.
Environmental stress factors, both chronic and acute, also contribute to the development of schizophrenia. These vary from person to person and examples might include such stressors as obstetric complications, malnutrition and emotional trauma.
How do these factors act and interact?
Some of the genes known to contribute to schizophrenia susceptibility have known functions in the brain, such as regulating calcium flow into neurons, governing neural circuit formation and mediating neurotransmission. All of these genes are involved in neurodevelopmental processes.
Prevailing theory suggests that defects in these genes and in their expression progressively weaken the brain’s ability to healthily adapt to physical and emotional stress factors in one’s environment.
Too many synapses may be lost and circuits in the brain may lose healthy connectivity. Eventually, usually around adolescence, an acutely stressful period may cause the brain to cross a threshold causing the first overt symptoms of the disease to emerge.
From biology to better potential therapies
Fortunately, scientists are already starting to apply their knowledge of schizophrenia’s causes to the process of making new therapies to prevent and treat the disease.
For example, the One Mind-funded lab of Dr. Carrie Bearden at the CAPPS psychosis prevention center at UCLA has successfully tested an emerging form of psychotherapy called Family Focused Therapy. This approach enables the patient and their family to cooperatively resolve the stressful issues in the patient’s life. The team has found that this therapy can reduce pre-psychotic symptoms and significantly enhance the patient’s ability to function in life.
Also, the UCSF lab of the One Mind Assistant Professor Dr. Vikaas Sohal has identified a class of neuron whose electrical activity is out of rhythm in schizophrenia. A hopeful hypothesis is that restoring healthy rhythms to these neurons — perhaps through a form of implant-administered deep brain stimulation — could restore healthy circuit connectivity and remedy the disease’s symptoms.