Dopamine: linking biology to symptoms We have known for more than 40 years that excessive dopamine transmission in the brain's mesolimbic system plays a key role in schizophrenia.
The most common theory about the cause of schizophrenia is that there are too many dopamine receptors in certain parts of the brain, specifically the mesolimbic pathway. 1 This causes an increase in mesolimbic activity which results in delusions, hallucinations, and other psychotic symptoms.
Risk factors
Having a family history of schizophrenia. Some pregnancy and birth complications, such as malnutrition or exposure to toxins or viruses that may impact brain development. Taking mind-altering (psychoactive or psychotropic) drugs during teen years and young adulthood.
Scientists believe that people with schizophrenia have an imbalance of the neurotransmitters (brain chemicals) serotonin, dopamine, and glutamate . These neurotransmitters allow nerve cells in the brain to send messages to each other.
In particular, GABA dysfunction is thought to lead to the disinhibition of glutamatergic pyramidal neurons and a loss of synchronous cortical activity. Postmortem studies also suggest that schizophrenia is associated with dysfunctional GABA signalling at the postsynaptic receptor level.
Schizophrenia is more common in winter and spring births. Children whose mothers experienced famine during the first trimester are more likely to develop schizophrenia. Pregnancy and birth complications increase the risk of developing schizophrenia.
Trauma may cause changes in the body and affect neurotransmitters in the brain, increasing the risk of psychotic symptoms or schizophrenia. Childhood trauma may trigger schizophrenia in those susceptible to it, and people may experience symptoms between their late teens and early 30s.
The truth is that while schizophrenia is influenced by genetics, it isn't directly inherited.
Unfortunately, most people with schizophrenia are unaware that their symptoms are warning signs of a mental disorder. Their lives may be unraveling, yet they may believe that their experiences are normal. Or they may feel that they're blessed or cursed with special insights that others can't see.
Personality disorders such as antisocial, borderline, histrionic, narcissistic, avoidant, dependent and obsessive-compulsive types have been detected in one third to one half of schizophrenia patients (Nielsen, Hewitt & Habke, 1997; Solano & Chavez, 2000).
Alcohol cannot cause schizophrenia. But alcohol, as well as several other drugs, can produce psychotic symptoms. “There are a lot of drugs, including alcohol, that can produce psychotic symptoms, but for most people those symptoms go away once the substance is out of their system,” says Dr.
The exact causes of schizophrenia are unknown. Research suggests a combination of physical, genetic, psychological and environmental factors can make a person more likely to develop the condition. Some people may be prone to schizophrenia, and a stressful or emotional life event might trigger a psychotic episode.
Researchers say that those who have experienced emotional abuse in early life are 3.5 times more likely to have schizophrenia-like experiences in adulthood.
A landmark literature review found that people who sustained a TBI were 60% more likely to develop schizophrenia, and risk was doubled among people who were already predisposed to schizophrenia based on a family history of the disorder.
People with schizophrenia experience difficulties in remembering their past and envisioning their future. However, while alterations of event representation are well documented, little is known about how personal events are located and ordered in time.
You're more likely to get schizophrenia if someone in your family has it. If it's a parent, brother, or sister, your chances go up by 10%. If both your parents have it, you have a 40% chance of getting it.
Trauma during childhood
Stressful events during childhood have a particularly strong link to schizophrenia. Studies from 2019 indicate that stress during critical phases of development can increase a person's lifelong vulnerability to psychosis.
Some researchers believe that anxiety may contribute to the development of schizophrenia, but it is not necessarily a direct cause. It is important to remember that schizophrenia is a complex illness with many risk factors and causes, and anxiety may be one aspect of it.
In most people with schizophrenia, symptoms generally start in the mid- to late 20s, though it can start later, up to the mid-30s. Schizophrenia is considered early onset when it starts before the age of 18. Onset of schizophrenia in children younger than age 13 is extremely rare.
As is the case with many major neuropsychiatric illnesses, the typical age of onset for schizophrenia is in late adolescence or early twenties, with a slightly later onset in females.