1. Schizophrenia is a highly disabling and costly medical disorder. In fact, it is ranked among the main conditions contributing to the global burden of disease.
2. Schizophrenia involves positive symptoms, such as delusions and hallucinations, and negative symptoms, such as flattened affect, cognitive impairment and lack of motivation.
4. The first symptoms usually start in the late teens or early adulthood. Rarely schizophrenia starts in childhood or in the elderly.
7. People with schizophrenia have higher rates of suicide.
9. Approximately 15-20% of the schizophrenic patients have the so-called deficit schizophrenia, a syndrome characterized by prominent negative symptoms. These patients have less addictions, depression and suicide rates, and less positive symptoms, such as dellusions and hallucinations.
10. No one knows exactly the etiology of schizophrenia. Nowadays, schizophrenia is thought of as an umbrella term which includes different diseases with different pathophysiologies and similar symptoms.
11. Concordance rates of schizophrenia in monozygotic twins range from 40 to 50%. Concordance rates in dizygotic twins range from 10 to 15 %.
12. We can conclude that schizophrenia really has genetic factors involved in its etiology, but they certainly do not explain all the pathogenesis. This study shows that 87% of the risk comes from genetic factors, while the remaining 13% comes from the environment. One of the most famous and well studied genes is the one that encodes the COMT enzyme.
13. There are associations between schizophrenia and genes of the major histocompatibility complex, which has immune functions. That supports the idea of some immunological etiology for schizophrenia.
14. Influenza during pregnancy is associated with a higher risk of developing schizophrenia (for the fetus).
15. Cannabis smokers might be at higher risk of developing schizophrenia. In fact, smoking cannabis might cause paranoia and other psychotic symptoms even in healthy subjects.
16. Antipsychotics, the main treatment for schizophrenia, are antagonists of the D2 dopaminergic receptor. That is the same system activated by cocaine, amphetamines, and all the other recreational drugs.
17. More than 80% of the patients have delusions. Delusions are fixed beliefs that resist even massive contradictory evidence.
18. Hallucinations are perceptions that don’t correlate with real stimuli from the environment. Delusions might serve partly as a subjective explanation for the hallucinations.
19. Schizophrenia is a chronic disease. Some patients are able to lead relatively normal lives, but most of them are permanently highly disabled.
20. John Forbes Nash Jr., a Nobel laureate, was schizophrenic. The picture A beautiful mind, starring Russell Crowe, is based on his life.
Original text in Portuguese.
Revised by my friend Noah Nakajima.