The announcement that taurine, an additive in the energy drink Red Bull, reduces psychotic symptoms won headlines yesterday. But the same conference where this was announced – the International Early Psychosis Association's annual meeting in Milay, Italy – has heard plenty of other reports on advances in understanding psychosis, from many different angles, and all of them offering hope for better treatments.
Vitamin D deficiency has been suspected for years to play a role in mental illness, particularly schizophrenia. Extensive evidence has been reported that diagnosis is more common among people born at high latitudes during winter or late spring. A presentation at the conference showed that this is not just a problem during the development of the infant brain, but can produce additional depression among adults already suffering from other mental illnesses.
In a study of 225 adult schizophrenia patients and 159 controls, Dr Mari Nerhus of the University of Oslo found those with low vitamin D levels were more prone to depression, even when sex, education level, and ethnicity were controlled for. Moreover, people experiencing vitamin D deficiencies performed worse on tests of mental processing speed and verbal fluency. In a statement, Dr Nerhus calls for “large scale randomized controlled studies” of people at risk of vitamin D deficiency, to test whether vitamin D supplements can restore capacity.
The same conference heard that thickening and blood vessel inflammation in the left carotid artery, the primary source of blood to the brain, is common among young people with early onset psychosis and bipolar disorder. The average thickness of the inner layer of the artery was 0.13 millimeters among patients with psychosis, but 0.08 millimeters among healthy controls.
The tests were conducted after diagnosis for the mental conditions, but researchers from the Karolinska Institutet, Sweden speculate that the inflammation may sometimes be detectable before symptoms of psychosis are clear. If so, ultrasound screening may provide a valuable form of early diagnosis, which could make an enormous difference to the prospects of successful treatment.
While the study did not explore cause and effect, the researchers raised the possibility that treatment with antipsychotic drugs may reduce, or even partially reverse the thickening, in which case the greater thickness would be even more noticeable among those who have yet to be diagnosed.
Schizophrenia is known to run in families, but the quest for genetic causes has been a slow one, since dozens, perhaps hundreds, of genes play a part. Regulatory regions that can increase or suppress gene activity also have an important role to play, but geneticists have been puzzled that these regions sometimes appeared not to be acting through genes located near them, as would be expected.
A paper published in Nature and coinciding with the conference explains this puzzle. By creating a map of 3D chromosome structures, a team led by Dr Daniel Geschwind of the University of California, Los Angeles revealed that certain regulatory regions, instead of influencing their immediate neighbors on a stretched out chromosome, regulate genes they come in contact with when the chromosome coils up.
The finding makes sense of some clinical studies, and could help provide targets against which antipsychotic drugs could be designed.