Researchers have identified a new gene linked to the development of psychosis, according to a paper published Monday in Nature Genetics. Primarily, the finding comes courtesy of a single unlucky family in Iceland with 10 members exhibiting both symptoms of psychosis and a specific mutation in a gene known as RBM12. A second, different mutation in the same gene was found among members of another family in Finland that also had a high prevalence of psychosis.
It's a difficult finding to parse. This is because psychosis is much more of a symptom than it is a disease unto itself. It's a condition or state of being, and it's very often fleeting. People have psychotic episodes. It's a bit like a fever or seizure. You don't get a diagnosis of "has seizures"—a seizure is a sign of something else. That something else might be epilepsy, brain injury, alcohol withdrawal, or even low sodium levels in the blood.
So, the new study was actually pulling out family members with one of a few severe mental disorders: schizophrenia, schizoaffective disorder, and psychotic bipolar disorder, which is basically really bad bipolar disorder. These are illnesses so severe that they can often lead to psychosis, a catastrophic implosion of the particular state of mind most of us take for granted in which we have a stable sense of self and generally what is and is not real. Our realities agree and so we're able to get along well enough in the world.
Pop culture has a bad way with psychosis. It does with every mental illness, of course, but schizophrenia, generally, and psychosis are like open-season for misinformation and stigmatization. Psychotic behavior is invariably seen as violent and antisocial, and it's common to conflate psychopathy with psychosis. The prior is a personality disorder characterized by a lack of empathy and the various other behavioral traits that normally keep us from being assholes to one another, while the latter is very often experienced as an inward collapse from the surrounding world, in non-technical terms.
Like the symptoms of schizophrenia, the symptoms of psychosis break down into what are known as positive and negative symptoms. And, like schizophrenia, the positive symptoms get all the press. These are delusions and hallucinations. Someone with psychosis might hear or see things that aren't there. It doesn't have to be voices—an auditory hallucination can just be some incongruent environmental noise or the sound of a strange phone ringing when there's nobody else around.
In a sense, delusions are similar. A delusion is just believing something that isn't true even in the presence of contradictory evidence or in the absence of supporting evidence. Often delusions have to do with persecution. Something is out to get you.
There are a lot of other symptoms of psychosis, but these are harder to get a bead on and they're harder to treat as well. Disorganized thinking is one. It is what it sounds like: a basic inability to collect a thought. It might manifest in scattered and-or nonsensical speech, a phenomenon known as "word salad." Other negative symptoms include things that just sound a lot like depression, like withdrawal, isolation, sleeping a lot (or not at all), and suicidal thoughts.
At the extreme of psychosis is catatonia, a deeply, profoundly sad condition in which someone becomes almost totally sealed off from the world. This might manifest as extreme unresponsiveness—staring blankly—or it might manifest as extreme agitation. Intense pacing, perhaps. It is likewise a mostly unresponsive state, albeit one in perpetual motion.
A psychosis gene is far from a silver bullet. You can have psychosis without a RBM12 mutation, which is crucial. It's a predisposition. This is something to keep in mind whenever you start hearing about mental health and genetics, generally. The hope here is that the finding may lead to new drug discoveries. That's important: In schizophrenia, there are essentially no good treatments for negative symptoms. It's a total curse, and, given the nature of negative symptoms, one that goes largely unseen. Instead, we get a lot of stereotypes and misinformation.