Diminished emotion expressivity but not experience in men and women with schizophrenia.

One of the most well-replicated findings in schizophrenia over the past 20 years is that people with this disorder do not outwardly express emotions even when they report experiencing the same amount of emotion as people without schizophrenia (e.g., Kring & Moran, 2008). Where differences are observed in reported experience between people with and without schizophrenia, they tend to be in reported arousal (e.g., Tremeau et al., 2009) or incongruent emotion experience (e.g., more negative emotion reported for positive and neutral stimuli; Cohen & Minor, 2010). Unfortunately, nearly all of these studies have been done exclusively with men; we know next to nothing about emotional responding in women with schizophrenia. How few studies have included women? Only 20 out of 61 non-overlapping studies across three meta-analyses of emotion experience in schizophrenia (Cohen & Minor, 2010; Llerena, Strauss, & Cohen, 2012; Yan et al., 2012) included at least 40% women. Of these studies, only five examined sex differences and found no significant sex differences (Berenbaum & Oltmanns, 1992; Habel, Krasenbrink, Bowi, Ott, & Schneider, 2006; Hudry, Saoud, d’Amato, Dalery, & Royet, 2002; Schneider et al., 1995; Volz, Hamm, Kirsch, & Rey, 2003). With respect to expressivity, only three studies have examined sex differences in schizophrenia. Two studies did not find sex differences (Davison, Frith, Harrison-Read, & Johnson, 1996; Simons, Ellgring, Beck-Dossler, Gaebel, & Wolwer, 2010). However, Davison et al. (1996) did not include a healthy comparison group and included twice as many men as women; Simons et al. (2010) included nearly twice as many men as women and did not assess emotional expressions. Tremeau et al. (2005) found that women with schizophrenia exhibited more facial movements when recalling an emotional event than did men, but did not assess emotion expressions. None of these studies assessed emotion experience. Thus, no study has examined sex differences, emotion expressions, and self-reported emotion experience in schizophrenia. Understanding emotional responding in women with schizophrenia is important for many reasons. First, women with schizophrenia differ from men on many aspects of the disorder, including a later age of onset, less pernicious course of illness, and less severe negative symptoms (e.g., Leung & Chue, 2000). Perhaps one reason why women with schizophrenia show a less severe illness course is because they do not show this same disconnect between emotion experience and expressivity. On the other hand, men and women may differ in negative symptoms in aggregate, but may not differ on all aspects of these symptoms. Negative symptoms are related to worse functional outcome in schizophrenia (Lysaker et al., 2004), and understanding whether there are sex differences in emotional responding, which is central to the expression and motivation/pleasure domain of negative symptoms, is essential for the assessment and treatment of all people with schizophrenia. Second, including equal numbers of men and women with schizophrenia better represents the prevalence of the disorder, which is roughly the same for men and women (McGrath, Saha, Chant, & Welham, 2008). Third, we can determine whether the disconnect between expression and experience reflects something about schizophrenia, or something about sex. Indeed, multitudes of studies with healthy people find that women are more expressive than men (for reviews see Brody & Hall, 2008; Kret & De Gelder, 2012). Women smile more than men, a finding that persists after accounting for factors such as culture and age (LaFrance, Hecht, & Paluck, 2003). This sex difference holds across different methods, including self-report (e.g., Hess et al., 2000; Simon & Nath, 2004), observer ratings in laboratory settings (e.g., Chentsova-Dutton & Tsai, 2007; Kring & Gordon, 1998) and naturalistic contexts (e.g., Campos et al., 2013), and EMG corrugator and zygomatic response (e.g., Huang & Hu, 2009; Lang, Greenwald, Bradley, & Hamm, 1993). By contrast, results on sex differences in reported experience are mixed (Brody & Hall, 2008; Hyde, 2014; Stevens & Hamann, 2012). Some studies find that women report more intense emotion experience than men (e.g., Huang & Hu, 2009), while others do not find sex differences (e.g., Kemp, Silberstein, Armstrong, & Nathan, 2004; Kring & Gordon, 1998). The mixed findings likely reflect the variety of methods (e.g., ecological momentary assessment; self-report trait questionnaires; adjective checklists following evocative stimuli) and definitions of emotion experience (e.g., responses to stimuli; retrospective reports across days). Taken together, these findings suggest two competing hypotheses about emotion expression and experience in women with schizophrenia. First, based on prior studies showing that men with schizophrenia differ in expression but not experience compared to men without schizophrenia, we can hypothesize that women with schizophrenia will show the same pattern. That is, compared to women without schizophrenia, women with schizophrenia will be less expressive but will not differ in reported experience. Second, based on prior studies showing that healthy women are more expressive than men, we can hypothesize that women with schizophrenia will be more expressive than men with schizophrenia yet will not differ in reported experience. To test these hypotheses, we examined emotion expression and experience in men and women with schizophrenia. Women without schizophrenia were chosen as the control group to examine whether women with schizophrenia would more closely resemble men with schizophrenia (competing hypothesis one) or healthy women (competing hypothesis two). We did not include a male control group as this was not directly relevant to these hypotheses, and several prior studies have demonstrated that men with schizophrenia differ from men without schizophrenia.