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What is schizophrenia? What causes it? What are the symptoms of schizophrenia? What are the treatments for schizophrenia? What do we know about and not know about schizophrenia? What are the controversies surrounding schizophrenia?
What is schizophrenia?
Although whatever it is affects around one in 200 adults, there is no clear or agreed definition. The best we have is a series of indicators, which consist of positive and negative symptoms. Positive symptoms are those where there is the presence of a behavioural indicator, and negative symptoms are those behaviours that would usually be there for well-functioning people but are absent.
For instance, schizophrenia is diagnosed if the person has persistent delusions or fixed beliefs in something that is not true, despite clear evidence to the contrary. Many people have delusions, but they are not so severe that their lives are impaired. Hallucinations of things that are not there in reality, on a persistent basis, are usually present, as is the person reporting that their thoughts, feelings and behaviours are not in their control.
As expressed by impaired communication, their thinking is disorganised, as is their behaviour. Their emotional responses can vary between seeming inappropriate and appearing restricted. Given the list of symptoms above, it will be no surprise that problem-solving of day-to-day problems is impaired, as are attention and memory.
An easy way to remember the key negative symptoms of schizophrenia is the 5As
- Affective flattening (mood and expression are impaired and restricted)
- Alogia (lack of conversation or poverty of speech)
- Anhedonia (the inability to feel or express pleasure)
- Asociality (lacking the capacity or rejecting social interaction)
- Avolition (a complete lack of motivation, even in the face of threat)
In very few cases, the causes are physical; and once treated, the symptoms abate. Among the few verifiable biological causes, known as secondary psychosis conditions, are thyroid diseases and other endocrine system disorders. Steroids can and do affect the mental health of some people who take them and, in a few cases, induce the symptoms of schizophrenia.
Here are just some of the other physical problems that can lead to schizophrenia-like symptoms (secondary psychosis):
- Hypo and hyperthyroidism (the thyroid gland is dysfunctional)
- Cushing disease (tumours producing steroids in the adrenal gland)
- Insulinomas (growths on the pancreas which interfere with insulin production)
- Porphyria (a genetic disease which interferes with haemoglobin)
- Tay-Sachs disease (a genetic disease which causes fatty tissue build-up in the brain)
- Niemann-Pick disease type C (also a genetic disease which causes fatty tissue build-up in the brain)
- Pheochromocytoma (a tumour growing from the chromaffin cells in the adrenal glands)
- Systemic lupus erythematosus (an auto-immune disease that damages the nervous system)
- Paraneoplastic limbic encephalitis (a limbic system disease usually associated with cancer)
- Cerebral malaria (a bacteria-based disease transmitted by mosquitoes)
- Narcolepsy (possibly caused by hypocretin deficiency – the theorised sleep regulator)
- Side effects from medications (many medications have known side effects that induce psychosis)
- Viral infections (some viruses have been known to induce schizophrenia-like symptoms)
Although many physical causes mimic schizophrenia, the above list accounts for only a tiny number of the 24 million cases worldwide (estimated by the World Health Organization).
It seems likely that physical health problems induce less than 1% of cases of schizophrenia. Very few cases of schizophrenia can be classified as secondary psychosis. No known pathogen is responsible for the vast majority of cases of schizophrenia.
When fMRI scans of people diagnosed with schizophrenia are viewed, differences in brain activity can be noted in some cases. However, our awareness that correlation with a problem is not causation of the problem leaves us no wiser; we don’t know whether any brain activity changes are causal or consequential.
What causes schizophrenia? We don’t know. We don’t even know if we are looking at one disorder or several different problems that cause similar symptoms.
There is a vast number of theories of the causes of schizophrenia. Most are very difficult, or impossible to test, and even if they could be validated, none comes with a treatment that can be shown to work on a reliable basis.
What are the treatments for schizophrenia? Frankly, my psychiatrist friends will not thank me for this, and there is no effective treatment. There is only amelioration of symptoms. In a huge number of cases, even that is not possible, and the only viable option is chronic sedation. Chronic sedation is so common that it has acquired a pejorative name: the chemical cosh. People with long-term, untreatable schizophrenia are not treated; they are sedated for life.
Anti-psychotics are thought to work by altering chemicals in the brain, such as dopamine, serotonin, noradrenaline and acetylcholine, with dopamine being the chemical most thought to be involved.
There is much theorising about why and how anti-psychotics ameliorate symptoms (without addressing the causes). Still, frankly, we don’t know what is going on, how, or why.
We know this; antipsychotics were discovered by accident in France as part of the development of antihistamines. Promethazine was noted to have sedative effects, and surgeons began using it before surgery to calm anxious patients. It was not long before it was used more widely to help people suffering from various mental health challenges.
All this took place in the complete absence of awareness of how the drugs had their effect. That ignorance continues today. Indeed, as a quick aside, we still don’t know how general anaesthetics work; we know that they switch off consciousness; how they do that is a mystery.
Around one-third of people who are diagnosed with schizophrenia recover. That tends to indicate that whatever is causing schizophrenia is not related to permanent brain changes,
Could schizophrenia be the result of chemical imbalances in the blood and brain? If so, we would expect to run blood tests, compare the blood of those people who have symptoms to those who do not and spot the difference.
Alas, we find no difference in most cases (99%+). It could be that there is a hugely important chemical of some type, of which, so far, we are unaware. If so, every researcher in the world, over many decades, has missed it.
That turns attention to non-chemical causes. Perhaps genes contain the answer.
There, too, we fall short; if schizophrenia were purely genetic in all cases, one-third of people who recover would not. Again, that indicates that the problem has multiple causes. Perhaps we are looking at multiple different processes that can lead to the same cluster of symptoms.
That is not to say there is no genetic element; there is. People who have a direct blood relative diagnosed with schizophrenia have a 10% lifetime risk of being diagnosed.
If both parents of a person were diagnosed as schizophrenic, there is around a 40% chance that person will be.
Again, with only a 40% chance coming from what, in theory, is a 100% genetic disposition, the indications are that schizophrenia is far from being purely a genetic problem.
Equally, if someone grows up with parents whose reasoning (and other) skills are impaired, they will likely copy the resultant dysfunctional behaviours as part of their development. As is the case in many areas of human study, separating nature from nurture is hugely problematic, if not impossible.
Although we can ameliorate its symptoms or chemically sedate those people whose symptoms cannot be minimised to the point of being able to function in society, schizophrenia is still a mystery to us.
Professor Nigel MacLennan runs the performance coaching practice PsyPerform.