Prevalence of schizophrenia compared to other well-known diseases
Schizophrenia is the most persistent and incapacitating of the major mental illnesses. The population that is at risk of developing the illness usually falls into the age rage of 16 to 30. Hence, it attacks people during their most productive years and, if left untreated, the illness can have a profoundly damaging effect on the patients, their families and their communities. Schizophrenia affects more than 2 million adult American men and women and approximately 1 out of every 100 people worldwide.
Depictions of schizophrenia in popular culture tend to cast this population as outcasts with split personalities or potential paranoid murderers walking around the streets ready to attack passersby. Such mainstream depictions of schizophrenia are far from accurate and portray the illness as a mere combination of hallucinations, delusions and paranoia. Even though these positive symptoms are the most widely known and conspicuous symptoms of schizophrenia, they are not necessarily the most important or characteristic ones. According to the Harvard Medical School’s Family Health Guide on Schizophrenia, “the negative symptoms of the illness are much more pervasive and persistent and have a much greater effect on a patient’s quality of life”. The negative symptoms are associated with disruptions to normal emotions, and will be the main focus of this blog.
Flat Affect: The absence or near absence of emotional response to a situation that normally elicits emotion.
Emotional flatness and lack of expressiveness, which is medically known as flat affect, is a typical negative symptom that people with schizophrenia suffer from. An analysis of the literature focusing on impaired emotional functioning in schizophrenia shows that flat affect is one of the most debilitating and treatment resistant clinical features of schizophrenia and is, interestingly, more common among men than women. Shtasel et al.’s (1992) study on phenomenology and function in first episode patients demonstrate that flat affect is a symptom of schizophrenia that is present at the onset of illness and is associated with “poorer premorbid adjustment, worse current quality of life, and worse outcome at 1-year follow-up”. Shtasel et al’s (1992) findings are based on the clinical assessment of facial emotional expressivity in this population and shed light into the correlation between presence of flat affect and deterioration of quality of life. This correlation is a significant finding, because it leads us to the question: Does flat affect only mean diminished facial emotional expressivity or are there other domains of affective dysfunction related to flat affect that lead to patients’ reporting of worse quality of life and poorer premorbid adjustment.
To answer a component of this question, Gur et al. (2006) designed a lab study where they examined the association between flat affect and emotion identification. They compared 63 patients with at least moderate severity of flat affect and 99 patients without flat affect and found that “patients with flat affect, compared with controls, were impaired severely on facial emotion processing tasks, one that required identification of happy and sad emotions and another that required differentiating among intensities within these emotions”. An interesting finding of their intensity differentiation task was that patients with flat affect responded inaccurately yet faster than controls while identifying the intensity of the emotions they were asked to rate. This finding suggests that, in patients with flat affect, there is a substantial decomposition of the normal relationship between accuracy and speed. This could have revolutionary implications for discovering the etiology of flat affect and a number of negative symptoms of schizophrenia.
My next blog post will focus on these implications and I will explore emotional processing in schizophrenia and the neural mechanisms contributing to emotional response deficits in this disorder. Tune in next week to learn more about the neural basis of emotion in schizophrenia!
Resources:
- Gaebel W, Wolwer W. Facial expressivity in the course of schizophrenia and depression. European Archives of Psychiatry and Clinical Neuroscience 2004;254:335-342.
- Gur RE, Kohler CG, Ragland JD, Siegel SJ, Lesko K, Bilker WB, Gur RC. Flat Affect in Schizophrenia: Relation to Emotion Processing and Neurocognitive Measures.Schizophrenia Bulletin (2006) 32 (2): 279-287.
- Komaroff, AL. Harvard Medical School’s Family Health Guide on Schizophrenia. New York: Free Press, 2006. Print.
- Shtasel DL, Gur RE, Gallacher F, Heimberg C, Cannon TD, Gur RC. Phenomenology and functioning in first episode schizophrenia. Schizophrenia Bulletin 1992;18:449-462.
So interesting– one of the studies that piqued my interest in emotion very early in my career (as a graduate student, in fact) was a study on this topic by Ann Kring and John Neale (1996; http://psycnet.apa.org/psycinfo/1996-00431-010). They found that whereas people diagnosed with schizophrenia exhibit less affect on their faces in response to emotionally-provocative film clips compared to people without schizophrenia, they reported similar subjectively experienced emotions and their skin conductance response was higher. That kind of disjunction is fascinating to me.
The reason why I started reading more about flat affect was that same paper. In fact, I will focus on this disjunction in my next blog posts. In line with Kring and Neale’s findings, Aghevli et al. published a paper in 2003, where they found that this disjunction between emotional experience and expression in schizophrenia not only occurs in response to non-social stimuli like film clips but also extends to the interpersonal domain. I will cover both of these studies in my 3rd blog post.