The relationship between emotional intelligence and quality of life in schizophrenia and bipolar I disorder

According to the World Health Organization (WHO), the term Quality of life (QoL) refers to “an individuals’ perceptions of their position in life in the context of the culture and value systems in which they live, and in relation to their goals, expectations, standards and concerns. It is a broad ranging concept affected in a complex way by the persons’ physical health, psychological state, level of independence, social relationships and their relationship to salient features of their environment” [1].

Over the last decades, QoL has gained importance as an outcome measure in health research, and successful treatment nowadays not only describes a reduction of specific symptoms, but also aims at a holistic approach to reach recovery [2]. Therefore, QoL may not only be seen as a reliable indicator of disease burden [3], but is also an important treatment and research target, e.g. in patients suffering from serious mental illness (SMI), which is defined as “mental, behavioral, or emotional disorder resulting in serious functional impairment, which substantially interferes with or limits one or more major life activities.” [4].

Patients suffering from SMI such as schizophrenia (SZ) or bipolar disorder (BD) report drastic impairments in QoL compared to healthy individuals [5, 6]. Schizophrenia is characterized by episodes of psychosis (delusions, hallucinations, disorganized thinking), as well as many other symptoms, such as cognitive deficits, social withdrawal, reduced emotional expression, or apathy. The course of the illness and the severity of symptoms can be very different from one individual to the other. Symptoms may occur continuously or as relapsing episodes. Bipolar disorder, on the other hand, is a mood disorder, mainly characterized by episodes of depressed or elevated mood. However, cognitive and psychotic symptoms may occur in this disorder as well, and both disorders are associated with high rates of suicidality and disability [7].

Cross-diagnostic comparisons have shown that patients with BD have better functional outcomes compared to those suffering from schizophrenia, but the two groups seem to achieve a comparable QoL in the course of illness [8‐10]. A better understanding of the factors influencing QoL in SMI may help to develop targeted interventions to improve subjective recovery in those affected. Among others, depressive symptoms, medical and psychiatric comorbidities, and treatment adverse effects have consistently been shown to negatively predict QoL in SMI in general, while objective recovery, i.e. symptom remission, resilience, and social cognitive skills have been associated with better QoL [8, 11‐13].

Generally, the term “social cognition” covers a broad field and comprises four primary domains: emotion processing, social perception, Theory of Mind (ToM) / mental state attribution, and attributional style / bias [14]. Previous research has documented the relationship between emotion processing abilities and QoL in BD. For example, deficits in recognizing fear [15] and in experiencing emotions have been demonstrated to be associated with reduced QoL in these patients [16]. In SZ, a number of studies have shown that social cognitive impairments exert a major influence on a patient’s psychosocial functioning and well-being [17‐19]. While emotion processing has been shown to predict successful employment and independent living [20, 21], the correct recognition of facial affect and affective prosody has been associated with interpersonal relationship patterns [22], communication [23, 24], and occupational functioning [24]. The investigation of hospitalized SZ patients has yielded a positive association between facial affect recognition and social competence, social interests, and personal hygiene [25]. Notably, further investigation is needed to understand the interrelations between the other subdomains of emotion processing (using, understanding, and managing emotions) and QoL, as subjective elements of recovery. Additionally, the impact of the nature of SMI in this regard are still not well understood and should be examined. We therefore chose a comparative approach to identify cross-diagnostic differences between SZ and BD. Accordingly, the current study concentrates on the relationship between QoL and Emotional Intelligence (EI).

Emotional Intelligence, a concept consolidated by Salovey and Mayer [26], focuses on personality traits and abilities enabling people to cope with both their own and others’ feelings [27]. According to their “ability” model, EI is understood as a combination of emotion-specific abilities: perceiving, using, understanding, and managing emotions. “Perceiving emotions” means the ability to recognize emotions accurately, while “using emotions” is about using emotions to enhance cognitive processes. “Understanding emotions” is the knowledge of how emotions interact with each other and change over time, and “managing emotions” means the ability to deal with and regulate emotions. This model suggests that EI is a skill, which can be developed and trained, in order to improve social cognitive abilities. Moreover, it can be measured objectively along the lines of conventional intelligence tests, which was the main reason for choosing it for the present investigation. In contrast, the “trait model” of Emotional Intelligence proposes that EI is based on self-perceptions of one’s emotional abilities, which are grounded in an individual’s personality and can be assessed with self-report measures.

The Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) [28] was developed to measure EI-performance according to the four-branch model, as presented by Brackett and Salovey [29]. We have previously shown comparable overall EI (MSCEIT total score) in patients diagnosed with SZ or BD, albeit SZ patients displayed significantly more deficits in most MSCEIT branches [30]. The most distinct between-group difference was found in the “understanding emotions” section. In order to expand on this previous research, we investigate the relationship between EI and QoL in an extended sample of clinically stable outpatients, and a non-psychiatric control group, with a special focus on QoL measured on the basis of objective life circumstances.

This cross-sectional study investigated the relationship between the social cognitive domain of Emotional Intelligence and quality of life in patients suffering from schizophrenia or bipolar I disorder. Of note and contrary to previous research, both subjective and objective QoL indicators were considered, i.e., subjective satisfaction with specific areas of life, and objective life circumstances (e.g., hours of occupation per week or frequency of contacts with family members and friends). The two patient groups showed comparable levels of overall EI and were largely comparable with regard to both subjective and objective QoL. However, the patient groups indicated significantly lower levels of EI and QoL compared to healthy controls. A significant relationship between EI and objective QoL was particularly seen in schizophrenia patients, however, overall effect sizes were small.

Our sample consisted of chronically ill outpatients with an average duration of illness of about 15 years, and mostly mild symptoms, who had been stable both from a symptomatic and a medication perspective before study inclusion. We therefore were able to study the persistent impairments associated with SMI, rather than the transient changes associated with episodes of relapse. In line with previous findings from our group [30], SZ and BD patients had comparable overall EI (MSCEIT total score) but differed significantly in most MSCEIT branches, with BD patients displaying less severe deficits. Although the MSCEIT total score lay within general population norms in both patient groups, healthy controls outperformed both patient groups.

Expectedly, and in line with earlier investigations [13, 43, 44], patients indicated lower QoL compared to controls, with no significant difference between patient groups. Nonetheless, our findings re-emphasize that both SZ and BD patients are in need of continuous psychosocial care, even when clinically stable and merely mildly ill.

With regard to a potential association between social cognitive abilities and QoL in SZ, a positive correlation between ToM capabilities and QoL has been reported [45]. Interestingly, that study did not find any association between emotion perception abilities and QoL, whereas others reported a positive correlation between the ability to perceive emotions and family network relationships [46]. Among the present schizophrenia sample, patients achieving higher scores in the “perceiving emotions”, “managing emotions” (i.e., emotion regulation), and “understanding emotions” branches of the MSCEIT, reported a higher frequency of social contacts. Intuitively, this makes sense, as impairments in these areas likely lead to difficulties in building and maintaining social relationships. It should be noted, however, that the two mentioned studies, and the present investigation, differ notably with regard to age and duration of illness of participants, and used different instruments to investigate social cognitive functioning. Accordingly, the three samples are not entirely comparable. Nevertheless, individuals with schizophrenia often feel socially isolated and disconnected from friends and family, which is partly due to lacking social emotional abilities [47].

In BD patients, “frequency of social contacts outside psychiatry” was the only BELP domain that positively correlated with EI. In contrast, Aparicio et al. did not find any significant correlation between EI and interpersonal relationships [48]. Contrary to our investigation, their study had exclusively included euthymic patients and did not use a specific instrument to measure QoL. However, mean MADRS and YMRS scores were also very low in the present BD sample and further studies are needed to investigate this issue.

Recently, the relationship between the “managing emotions” branch of the MSCEIT and psychosocial functioning in SMI was examined. Significant positive associations in SZ, but not in BD (except an association between “managing emotions” and “interpersonal relations”), were reported [49], which is in line with our results. We suggest that the observed differences between diagnostic groups may be caused by differences in illness severity, since BD patients were symptomatically remitted, as indicated by very low MADRS and YMRS mean scores, whereas schizophrenia patients cannot be regarded as remitted, even though a PANSS mean score of 53.9 ± 12.9 indicates merely mild symptom severity. Since ToM and EI as assessed with the MSCEIT inter-related and are partly overlapping constructs [50], one can further speculate on the relevance of ToM, i.e. the ability to understand the mental states of others and “to reflect one`s own and others minds” [51] in this regard. ToM is a known prerequisite for empathy and is thus essential for social interactions in everyday life. Both, patients with SZ and BD have previously been shown to have marked ToM impairments [52] which in SZ, have been associated with reduced QoL [45]. Differences in ToM performance may therefore be the underlying factor for the stronger relationship between EI and QoL in our schizophrenia sample, however, further studies are needed to confirm this assumption.

According to our findings, patients suffering from SZ or BD may have different needs to achieve recovery, and a positive effect of a training of socioemotional abilities on patients’ QoL, may be expected in those suffering from SZ. Previous studies point to positive long-term effects of an EI training program on clinical outcomes in SZ patients [53]. From a clinical perspective, it would be of interest to investigate to what extent such a training also impacts QoL and whether this effect might persist over time.

Our study has several limitations. Firstly, a larger sample might have revealed more and stronger associations between the different subdomains of EI and QoL, and clearly, the cross-sectional design does not allow conclusions on causality. Secondly, we disregarded the potential influence of medication on the outcomes studied. Clearly, the compounds prescribed to our patients may have had a different impact on outcomes. However, as all patients were clinically stable, we can at least disregard efficacy differences between the different drugs. Lastly, it is debatable whether the objective QoL indicators calculated in this study suffice as “objective” measures without a third-party verification.

In summary, our results show that EI and QoL are interrelated. As hypothesized, this association was more pronounced in SZ than in BD patients, however, overall effect sizes were small. Accordingly, our findings should be interpreted cautiously, and first and foremost need to be replicated in larger samples. In a further step, it should be investigated whether social cognitive training programs targeting EI may especially help SZ patients to promote their QoL.