This article will cover:
· What is Schizophrenia?
· What are the causes and risk factors?
· What are the treatment options for Schizophrenia?
What is Schizophrenia?
Schizophrenia is a severe mental disorder affecting a person’s thoughts, feelings and behaviour [16]. It is accompanied by psychosis, characterised by a loss of touch with reality caused by a disruption in information processing. As a result, a person might have difficulties distinguishing what is real and what is not [17]. In the figure above, you can see the DSM-5 criteria for diagnosing Schizophrenia.
Schizophrenia is considered a spectrum disorder: individuals differ in regards to the symptoms they exhibit and their severity [1]. Moreover, the symptoms of schizophrenia can be divided into three categories: positive, negative and disorganised [17, 19].
Positive (psychotic) symptoms refer to those that are experienced in addition to reality, such as delusions and hallucinations. Delusions are persistent false beliefs. They are often paranoid in nature, for example the person believes someone is ‘out to get them’ [17]. Hallucinations are sensory perceptions that are not real (i.e., there is no real stimulus), but the person experiencing them thinks they are [12]. The most common form of hallucinations among schizophrenic people are auditory (hearing voices). While visual hallucinations are also somewhat common, tactile, olfactory and gustatory ones are quite rare [17].
Negative symptoms refer to impairments in the person’s abilities or a decrease in regular behaviours. These include lack of motivation and interest, reduced expression of emotions, diminished feelings of pleasure, reduced desire for social contact and planning difficulties [16, 17].
Disorganised symptoms include confused and disorganised speech and thinking, difficulties with logical thinking and disorganised/abnormal movements [17]. Catatonia is a common behavior, characterised by lack of movement, speech and response to stimuli. The catatonic person often holds unusual postures for extended periods of time [8].
In terms of prevalence, schizophrenia affects less than 1% of the world population and it is slightly more prevalent in men than women [2]. Men also have a lower age of onset (late teens – early adulthood) compared to women (late 20s – 30s) [7].
Causes and risk factors
Research suggests that schizophrenia is a result of various combinations of genetic, biological and environmental factors.
Genetic factors
The heritability estimate of schizophrenia is roughly 80%, suggesting that schizophrenia has a large genetic component [10]. It is not possible that one specific gene alone would lead to schizophrenia [4, 10, 16], however researchers discovered a combination of gene variations which can increase the risk of developing this mental illness [16].
This does not mean that if a person’s close family member has schizophrenia they will necessarily develop it as well [16]. For example, it is possible that only one of the identical twins develops schizophrenia even though they share 100% of their DNA [4]! This shows that genetics is not the only contributing factor. However, people with first-degree relatives suffering from schizophrenia are 6 times more likely to develop it than the general population [3].
Brain structure and chemistry
Schizophrenia has been linked to disrupted functioning of the dopaminergic system in the brain. This means that people with schizophrenia have excessive levels of the dopamine neurotransmitter, especially in the limbic system, which is the brain area responsible for emotional regulation [19]. Researchers hypothesize that this could be the cause of the psychotic symptoms explained earlier. Furthermore, decreased levels of dopamine [7] and glutamate [10], (another neurotransmitter) in the prefrontal cortex may explain some of the negative symptoms associated with schizophrenia. The prefrontal cortex is the area responsible for higher executive functions and regulation of behaviour.
Moreover, disruption in proper brain development, especially of the prefrontal cortex, can also be a contributing factor [15].
Environmental factors
A variety of environmental factors are thought to contribute to schizophrenia. Prenatal factors such as malnourishment, maternal stress, blood type incompatibility (between mother and the foetus) or maternal infection can increase the risk of developing schizophrenia by disrupting the normal neurodevelopment of the foetus. Moreover, birth complications such as hypoxia or premature birth are also risk factors [5, 7].
Cannabis use in adolescence has also been linked to schizophrenia [7], as the excessive use is thought to increase the risk of developing it in individuals that already have a genetic predisposition. The precise mechanism of this effect is not fully clear, however it seems that THC (the psychoactive ingredient of cannabis) can trigger psychotic episodes by increasing dopamine levels in the brain [7, 11]. Interestingly enough, another component of cannabis, namely CBD, actually helps attenuate psychotic symptoms [7]!
Lastly, other risk factors include living in a stressful environment, poverty, exposure to infectious diseases [4, 7], exposure to lead and other heavy metals [9] and living in urban areas [6].
Treatments for schizophrenia
Around 50% of patients with schizophrenia either recover or their symptoms significantly improve [18]. This prognosis is generally worse for men, people with early-onset and those who lack social support [19]. Schizophrenia is most commonly treated with medication, but psychosocial therapies aimed at regaining social functioning are also important.
The drugs used to treat schizophrenia are called antipsychotics. These reduce the psychotic symptoms by restoring the normal dopamine levels in the brain. First-generation antipsychotics have been replaced by second-generation ones due to their serious side effects, but their effectiveness remains the same [16, 19]. First and second simply refer to different classes of drugs that are present in the medications.
Various types of therapy also aim at helping schizophrenic patients to manage their symptoms and regain their social functioning. Cognitive-behavioural therapy can help with symptom management but it does not treat the underlying causes [13, 14]. Family interventions are also important, as they educate family members about the illness, as well as improve relationships between the patient and the family in case they have been affected by the diagnosis[14]. Indeed, it is really hard to accept and deal with schizophrenia inside the family. Also, social skills training is crucial for improving social functioning [14].
In conclusion,
schizophrenia is NOT a split personality! People affected by schizophrenia experience psychosis and a variety of other symptoms. The causes of schizophrenia are most likely a combination of genetic predisposition, disruption in brain functioning and environmental factors. Treatment consists mainly of antipsychotic medication, often accompanied by CBT or other psychosocial therapies that help patients improve their social and emotional functioning.
Some extra resources:
- Movie - ‘A Beautiful Mind’ – Biography about mathematician John Nash who suffered from schizophrenia. This movie portrays schizophrenia quite accurately but keep in mind that it is still a movie so some things are slightly dramatized!
- Podcast - ‘Inside Schizophrenia’ – people talk about their experiences with schizophrenia https://open.spotify.com/show/3qnxXtGNPpyRIRJCcouYFL?si=NRy2ZB3zRw6LL1IU_-BM_w
- Article (6 min read) - The media portraying Schizophrenia https://medium.com/@Mentallyawareng/the-problem-with-how-the-media-portrays-schizophrenia-34bf0f8b59be
References
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16. The National Institute of Mental Health (2019) Schizophrenia. Retrieved March 20, 2021, from https://www.nimh.nih.gov/health/topics/schizophrenia/index.shtml
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