The Roles of Implicit Memory Bias,Depression,and Metacognitions in Men and Women With Coronary Artery Disease

Abstract

The purpose of this research was to examine the role of implicit memory bias, depression, and metacognitions in coronary artery disease (CAD) and the relationships between implicit memory bias, depression, and metacognitions based on gender, age, and educational status. Participants were 30 patients with CAD and controls who were selected through a purposive sampling method in Iran. A demographic questionnaire, the Meta-Worry Questionnaire-30; the Beck’s Depression Inventory–II; and the Word Stem Completion Software were used in this study. Resulting data demonstrated that patients with CAD had significant higher levels of depression, metacognitive worry, and negative-mood-inducing words than individuals in the control group. Also, individuals in the control group had significant higher performance on neutral-mood-inducing words than patients with CAD. Depression and metacognitive variables were significantly related to negative- and neutral-mood-inducing words in the total sample. Findings did not support significant relationships of age and educational level to depression, metacognition, and the implicit memory bias in males and females.

Keywords

implicit memory bias depression metacognitions coronary artery disease

Coronary heart disease (CHD) is a major risk factor of death for both genders in the world. However, CHD is about two to five times more common in males than in females (Jousilahti, Vartiainen, Tuomilehto, & Puska, 1999). CHD is caused by the upsurge of plaque in the arteries of heart (Gaziano, Ridker, & Libby, 2011). CHD is a global problem, and the risk of disease can be amplified when societies undergo urbanization (Yusuf, Reddy, Ounpuu, & Anand, 2001). CHD is also called coronary artery disease (CAD). CAD occurs when the cells lining the arteries are impaired from plaques accumulating on the vessel lining. However, CAD is the most common origin of CHD, and many practitioners think of CHD as the end product of CAD such as heart failure (Morrow & Gersh, 2008). Altogether, research literature in behavioral sciences and medicine suggests that psychological factors play a direct role in CAD (Krantz & McCeney, 2002). Therefore, the purpose of this study was to investigate the roles of implicit memory bias, depression, and metacognitions in CAD and to explore the relationships between implicit memory bias, depression, and metacognitions based on gender, age, and educational status.

Coronary Risk and Cognitive Impairments

Many studies have shown that CAD is a main risk factor for cognitive functions, particularly for those in the middle-age and older. Research has indicated that indicators of vascular diseases are related to cognitive functions and their impairments in the older ages (Breteler et al., 1994; Desmond, Tatemichi, Paik, & Stern, 1993). For instance, the effects of cerebrovascular diseases and stroke on cognitive impairments such as memory deficits and dementia were well established (Kalmijn, Feskens, Launer, & Kromhout, 1996; Petrovitch et al., 1998). Additionally, some scholars have suggested a linkage between CAD and some cognitive functions in middle-aged adults (Singh-Manoux et al., 2008). A recent study has indicated that all inpatients with the diagnosis of dementia and cognitive impairments also had a higher rate of CAD (Bajenaru, Antochi, & Tiu, 2010). Particularly, coronary risk was associated with a significant reduction in cognitive functions in males (Elwood, Pickering, Bayer, & Gallacher, 2002). Therefore, the relationship between CAD and prevalence of mild cognitive impairment in inpatients showed the same underlying etiologies in both phenomena (Roberts et al., 2010). However, implicit memory bias is a type of prevalent cognitive impairment in many psychological disorders such as anxiety and mood disorders (Ellwart, Rinck, & Becker, 2003; Graf & Schacter, 1987; Rasti & Tghavi, 2007). For example, patients with severe depression illustrated a mood-congruent memory (MCM) bias in their implicit memory among individuals without the same disorder (Ellwart et al., 2003). According to network theory, implicit memory bias is a type of MCM that results in qualitative changes in memory functions such as better recall of negative information (Bower, 1981). Williams, Watts, MacLeod, and Mathews (1997) suggested that implicit memory bias could be influenced by processes in the preattentive phase of memory. Therefore, implicit memory bias can be defined as the type of cognitive bias that operates inextricably with human memory (Eysenck & Byrne, 1994). Implicit memory bias involves the subconscious biasing of the memory system that activates a few mood-congruent feelings, cognitions, and behaviors, and it can inhibit normal memory functions. Thus, implicit memory bias might influence encoding and retrieval of information at subconscious levels in humans (Eysenck & Byrne, 1994). In practice, implicit memory bias measured by uses of memory in a stem-completion task helps investigate the effects of automatic or unconscious stimuli on memory retrieval (Bower, 1981; Williams et al., 1997). However, there is a lack of evidence about the possible role of implicit memory bias as a cognitive impairment in CAD, which highlights the importance of this study. This study suggests that implicit memory bias can influence the occurrence of CAD by retrieval of negative-mood-congruent words.

Depression and CAD

Research on the behavioral sciences has supported the major role of depression in CAD (Krantz & McCeney, 2002, Vural, Satiroglu, Akbas, Goksel, & Karabay, 2009). Additionally, more than 60 prospective studies in the four preceding decades have affirmed the linkage between clinical features of depression and the therapeutic prognosis in individuals with CAD ( Frasure-Smith & Lespérance, 2006 ). In sum, investigations indicated that depression is three times more common in patients with acute myocardial infarction than in normal individuals ( Thombs et al., 2006 ). Overall, depression was a risk factor of CAD in males (Ford et al., 1998). Theoretically, there are two biological and behavioral approaches for explaining the role of depression in the occurrence of CAD ( Thombs et al., 2006 ). Thus, this study suggests that depression can influence the occurrence of CAD by evoking of negative-mood-congruent emotions.

Metacognitions and CAD

Many studies have suggested that anxiety and its worry component are key risk factors in the development of CAD (Kubzansky, Kawachi, Weiss, & Sparrow, 1998). Studies have indicated that anxiety and pathological worry would increase the risk of CAD by (a) affecting health-related behaviors, (b) increasing atherogenesis, and (c) triggering fatal coronary events, through arrhythmia, plaque rupture, coronary vasospasm, or thrombosis (Kubzansky et al., 1998). A recent meta-analysis showed that anxiety is a major risk factor for the occurrence of CAD (Roest, Martens, de Jonge, & Denollet, 2010). In sum, anxiety disorders could influence the incidence of CAD, particularly in males (Vural et al., 2009). Similarly, Kubzansky and colleagues indicated that the high levels of worry in specific domains of life might increase the risk of CAD in older men. These worry domains include social conditions, health, finance, self-definition, and aging (Kubzansky et al., 1997). Metacognitive theory was a useful explanation for understanding the possible role of worry in CAD. In this theory, metacognitions refer to the internal cognitive factors that control, monitor, and appraise thinking. It was classified into metacognitive knowledge, experiences, and strategies (Wells, 2009). Therefore, metacognitions can direct attention, determine the style of thinking, and direct coping respon ses in the way that repeatedly increase dysfunctional knowledge among people (Wells, 2009). This study suggests that metacognitive worry can influence the incidence of CAD by activating impetuous schemas for negative thinking and emotions.

The Present Study

This study was founded on behavioral sciences, metacognitive, negative affectivity, and mind–body interaction theories for explaining the roles of implicit memory bias, depression, and metacognitive worry in CAD (Gordon & Hobbs, 2011; Jerry & James, 2005; Krantz & McCeney, 2002; Wells, 2009). Krantz and McCeney (2002) conceptualized a psychosocial risk model in CAD that included five factors: acute and chronic stress, hostility, depression, social support, and socioeconomic status. They suggested that negative emotions and cognitions might predispose people for the incidence of CAD. Similarly, Jerry and James (2005) suggested that negative dispositions such as depression produce negative affectivity and that this is a main risk factor for CAD. According to metacognitive theory, disturbances in thinking and emotion might emerge from metacognitions such as worry (Wells, 2009). Metacognitive theory was useful for understanding the roles of cognitive impairments such as implicit memory, depression, and anxiety in CAD (Potvin, Forget, Grenier, Preville, & Hudson, 2011). Finally, commonsense theory of mind–body interaction suggests that a person has both a mind and a body and that the quality of mind–body interaction can mediate sensations (Gordon & Hobbs, 2011). This theory speculated that impaired functions in the mind could produce impaired sensations and disturbed mental control, and these impaired psychological functions in turn would produce damaged functions and diseases in the body. Therefore, this study suggests that cognitive functions such as implicit memory bias and negative emotional problems such as metacognitive worry and depression have potential roles in the incidence of CAD. In fact, these three constructs mainly contain some forms of cognitive impairments, and thereby would probably play significant roles in the occurrence of CAD. Altogether, this study postulates that implicit memory, depression, and metacognitive worry influence health-relevant cognitions, emotions, and health behaviors in negative ways and increase psychological distress and negative emotions and that these cognitive-behavioral changes might alter cardiovascular function in humans abnormally. In addition, this study conceptualized that implicit memory bias, depression, and metacognitions can be considered three types of cognitive impairments. These types of cognitive impairments may decrease personal ability to attain higher levels of positive experiences and emotions, which in turn increase negative moods and decrease a person’s ability to face a variety of difficult situations. In fact, when implicit memory, depression, and metacognitive worry are continuing over time they influence the physical health functions negatively, and they can facilitate the occurrence of physical diseases such as CAD. In addition, studies have shown inconsistent evidence about the roles of some demographic factors in cognitive impairments such as implicit memory bias, depression, and metacognitions. For example, investigations indicated that age, gender, and educational status have significant roles in depression and metacognitive variables (Addis, 2008; Bjelland et al., 2008; Pratt & Brody, 2008). However, studies revealed inconsistencies about the roles of age, gender, and educational status in implicit memory bias (Small, Hultsch, & Masson, 1995; Zeitlin & McNally, 1991). Therefore, the purpose of this study was to examine the roles of implicit memory, depression, and metacognitive worry on the occurrence of CAD based on age, gender, and education status in an Iranian sample. The first hypothesis of this study was that patients with CAD would have higher levels of depression, metacognition, and implicit memory bias when compared with a control group without evidence of CAD. The second hypothesis of this study was that depression, metacognition, and implicit memory bias constructs would have significant relationships in this sample. The third hypothesis of this study was that age and educational status would have significant relationships to depression, metacognition, and implicit memory bias in males and females.

Method

Sample

Participants included 30 individuals (15 patients with CAD and 15 normal individuals without evidence of CAD and other health-related problems) from Shiraz, Fars Province, Iran. The clinical sample was selected by purposive or judgment sampling method within an ex post facto design. The purposive sampling method starts with a purpose in mind, and the sample is thus selected to include people of interest and exclude those who do not suit the purpose (Palys, 2008; Tongco, 2007). The mean and standard deviation of age for the total sample were M = 42.06 and SD = 4.49. The mean and standard deviation of age for individuals with and without CAD were M = 42.06, SD = 4.49, and M = 41.33, SD = 4.11, respectively. This sample included 11 males and 4 females with and without CAD. The level of education of this sample ranged from elementary (n = 3), guidance (n = 2), high school (n = 5), and undergraduate (n = 5) levels in individuals with and without CAD.

Instruments

The demographic questionnaire included items on age, gender, and the level of education. The three measures used were the following: (a) the Meta-Worry Questionnaire–30 (MWQ-30), (b) Beck’s Depression Inventory–II (BDI-II), and (c) the Word Stem Completion Software (WSCS).

Meta-Worry Questionnaire–30

The MWQ-30 (Wells, 2005) assesses thoughts and ideas about worrying with respect to the metacognitive model in the context of DSM-IV generalized anxiety disorder (GAD). The MWQ-30 consists of 7 items that reflect dangers of worrying. All items are rated in a 4-point Likert-type scale ranging from 1 =never to 4 = almost always. The MWQ-30 is significantly correlated with other measures of metacognition. The discriminative validity of the MWQ-30 was confirmed in patients with GAD (Wells, 2005). The psychometric properties of the Persian-language version of MCQ-30 were supported in Iranian culture (Shirinzadeh, Gudarzi, Ghanizadeh & Naghavi, 2008). Cronbach’s alpha coefficient for the MWQ was .95 in this study.

Beck’s Depression Inventory–II

The BDI-II (Beck, Steer, & Brown, 1996) is a 21-item self-rating scale. The BDI-II requires respondents to endorse statements characterizing how they have been feeling throughout the past 2 weeks. The BDI-II is designed to measure the presence of depression, and each answer on all items is scored on a scale of 0 to 3. A total scores 17 or more indicates degrees of abnormal depression that needs clinical intervention and treatment. The validity and reliability of BDI-II were confirmed in different populations and samples (Beck et al., 1996). The reliability and concurrent validity of BDI-II-Persian as a measure of depressive symptoms was confirmed in Iranian studies (Ghassemzadeh, Mojtabai, Karamghadiri, & Ebrahimkhani, 2005). Cronbach’s alpha coefficient for the BDI-II was .92 in this study.

Word-Stem Completion Software

The WSCS (Rasti & Tghavi, 2007) is founded on the word association method in depth psychology. In the WSCS, participants are given a list of study words and then asked them to complete word “stems” consisting of three letters with the first word that comes to mind. This technique involves an exchange of words that are associated with exploration of complexes in the personal unconscious. Jung recognized the importance of thoughts, feelings, memories, and perceptions that are organized around a central theme by using the word association test. The word association test has been used extensively in psychology to assess the personality of individuals (Russell, 1970). Also, the word association test presents a useful tool in the construction of information retrieval thesauri, particularly to recognize how end users classify vocabulary about a central concept (Spiteri, 2002). However, this test with modern forms is applied in cognitive psychology. For example, Watkins (2002) suggested that implicit MCM bias is a tendency in depressed individuals because they tend to retrieve more unpleasant information from memory than in normal individuals. MCM has been studied frequently with explicit memory tests, but a few studies have investigated MCM using implicit memory tests such as the word association method. Implicit memory studies have shown that (a) an implicit MCM bias does not emerge to exist when perceptually driven tests are applied, (b) implicit memory bias can be established when word or conceptually driven tests are used, and (c) not all conceptually driven tests can show implicit MCM bias (Watkins, 2002). Therefore, this study used the WSCS to investigate the role of implicit memory bias in CAD. The WSCS is a tool for word completion, which was invented by Macromedia Authorware program in the Persian language (Rasti & Tghavi, 2007). The WSCS includes 30 words based on word stem completion perception. The WSCS consists of two factors, negative moods (15 words) and neutral moods (15 words), and tests the effect of negative and neutral words on word comprehension as indicators of implicit memory bias. The negative-mood-inducing words by word stem completion percept ion consist of threat, danger, and sadness words of various lengths, whereas neutral-mood-inducing words are emotion-free without any positive or negative valence. Each word stem completion indicated how the participant felt on negative and neutral categories. All words for stem completion are of three or four letters. The roots of the target words that are active in implicit memory can be complete by the participants with a higher probability by their MCM system. The presentation intervals of word stem completion to all participants about the root word and the intervals between pairs of words were between 10 and 1.5 seconds, respectively. For accurate interval presentation by participants, all words are presented to them individually with similar intervals during the WSCS. The administration of the WSCS takes about 20 minutes, and it can be implemented by a professional with a bachelor’s degree in clinical psychology. The WSCS was invented by Rasti and Taghavi for assessment of implicit memory bias in patients with GAD and major depression disorder in 2007. According to authors, the validity and reliability of this software was satisfactory (Rasti & Tghavi, 2007). The concurrent validity of the WSCS was examined based on its correlation to the word stem completion task (Warrington & Weiskrantz, 1970), r = .32. The reliability of the WSCS for negative-mood-inducing and neutral-mood-inducing words was tested, and Cronbach’s alpha internal consistency in the present study was .88 and .84, respectively.

Procedure

This sample was selected based on a purposive sampling method (Palys, 2008; Tongco, 2007). Then, individuals in the control group were matched with the demographic variables of participants in clinical group. Individuals in the CAD group were assigned from public and private hospitals. Therefore, patients with CAD were included in this project if they met the following criteria: (a) the patient have the full clinical features of CAD based on the diagnosis by a cardiologist, (b) the patient was under treatment for CAD by a cardiologist, (c) the patient is fluent in the Persian language, and (d) the patient is willing to participate in this study. However, all individuals in the control group were evaluated for CAD and other diseases by physicians from different specialties, including cardiology, hematology, immunology, neurology, rheumatology, and internal medicine. Also, individuals in the control group were evaluated for depression, anxiety, and other mental disorders by two clinical psychologists. After informed consent was obtained, the participants completed a demographic sheet and the three measures. In this study, the demographic questionnaire and all measures were completed individually by participants in both the clinical and control groups. Participants in the clinical group were provided counseling and psychotherapeutic services as compensation for their participation in this study, since they all asked for psychotherapeutic interventions about their emotional problems. Each participant in the control group had a token compensation of 200,000 Rials for the time spent in this study.

Results

The first hypothesis of this study was that patients with CAD would have different levels of depression, metacognition, and implicit memory bias when compared with a control group without evidence of CAD. Four t tests for independent groups were conducted to compare the means and standard deviations between the clinical and control groups in all constructs. Findings indicated patients with CAD had significantly higher depression, t(28) = 2.62, p < .01, metacognitive worry, t(28) = 2.32, p < .02, and negative-mood-inducing words, t(28) = 5.11, p < .0001, than individuals in the control group. However, individuals in the control group had significantly higher neutral-mood-inducing words than patients with CAD, t(28) = −4.67, p < .0001 (Table 1). Also, to carefully examine the between-groups and within-group differences in the first hypothesis, four nalyses of variance were conducted to evaluate differences between patients with CAD, control, and the total groups with regard to their depression, metacognition, and implicit memory bias. Findings showed significant differences between these groups, and patients with CAD had the highest levels of depression, F(1, 29) = 6.89, p = .01, metacognitive worry, F(1, 29) = 5.38, p = .02, and negative-mood-inducing words, F(1, 29) = 26.18, p = .0001, than the control group and the total group. However, individuals in the control group had the highest performance on neutral-mood-inducing words, F(2, 29) = 21.89, p = .0001, than patients with CAD and the total sample (Table 2).

Table 1.

Comparison of Depression, Metacognitive Worry, and Implicit Memory Bias in Patients With CAD and Control Groups

	Groups
	CAD		Control
Independents	M	SD	M	SD	t	p
Depression	15.86	2.41622	14.0667	1.09978	2.62	.01
Metacognitive worry	18.1333	3.04412	15.9333	2.05171	2.32	.02
Negative-mood-inducing words	20.4000	2.50143	12.4000	5.51362	5.11	.0001
Neutral-mood-inducing words	9.6000	2.50143	17.2000	5.77185	−4.67	.0001

Note. CAD = coronary artery disease.

Table 2.

Comparison of Depression, Metacognitive Worry, and Implicit Memory Bias in Patients With CAD, Control, and the Total Groups

	Groups
	CAD		Control		Total
Dependents	M	SD	M	SD	M	SD	F	p
BDI-II	15.86	2.41	14.06	1.09	14.96	2.05	6.89	.01
MWQ	18.13	3.04	15.93	2.05	17.03	2.78	5.38	.02
Negative-mood-inducing words	20.40	2.50	12.40	5.51	16.40	5.85	26.18	.0001
Neutral-mood-inducing words	9.60	2.50	17.20	5.77	13.40	5.83	21.89	.0001

Note. CAD = coronary artery disease; BDI-II = Beck’s Depression Inventory–II; MWQ = Meta-Worry Questionnaire.

To investigate the second hypothesis, a correlation was computed to evaluate the relationships of depression, metacognitions, and implicit memory bias constructs with each other. A p value of less than .05 was used as an indicator for significance. This was computed among the four variables in an effort to assess the degree that shows significant relationships between depression, metacognition, and subscales (i.e., negative-mood-inducing words and neutral-mood-inducing words) of implicit memory bias (Table 3).

Table 3.

Depression, Metacognition, and Implicit Memory Bias Correlation Coefficients in the Total Sample

Variables	MWQ	Negative-mood-inducing words	Neutral-mood-inducing words
BDI-II	.411**	.605**	−.590**
MWQ		.522**	−.413**
Negative-mood-inducing words			−.991**

Note. BDI-II = Beck’s Depression Inventory–II; MWQ = Meta-Worry Questionnaire.

p ≤ .05. **p ≤ .01.

The third hypothesis of this study was that age and educational status would have significant relationships with depression, metacognition, and implicit memory bias in males and females. To investigate the possible differences for genders in the third hypothesis, age and educational level as continuous variables were added to the correlation test. Educational level was measured by the number of years each participant attended school. Likewise, the age of each person in a group was used as a score that formed a continuous variable in the correlation test. Then, two multiple correlation tests were computed for relationships of age and educational level with depression, metacognitions, and implicit memory bias for males and females. Overall, significant correlations were not found for age and educational level with depression, metacognitions, and implicit memory bias in both genders (Table 4).

Table 4.

Age, Educational Level, Depression, Metacognition, and Implicit Memory Bias Correlation Coefficients in Males and Females

Groups	Variables	Depression	Metacognitions	Negative-mood-inducing words	Neutral-mood-inducing words
Males	Age	−.096	.182	−.140	.165
	Educational level	−.147	.080	−.217	.174
Females	Age	−.091	.136	.125	−.147
	Educational level	.132	−.170	.004	.001

Note. *p < .05. **p < .01.

Discussion

The results from this study, with regard to the first hypothesis, showed that patients with CAD had significantly higher levels of depression, metacognitive worry, and negative-mood-inducing words than individuals in the control group, whereas individuals in the control group had significantly higher performance on neutral-mood-inducing words than patients with CAD. These findings affirmed the roles of depression, metacognitive worry, and negative-mood-inducing as three causal risk factors in the incidence of CAD. Also, the present findings are consistent with studies that supported the effects of implicit memory, depression, and anxiety on the development of CAD in adulthood (Kalmijn et al., 1996; Potvin et al., 2011; Vural et al., 2009). Also, these findings are congruent with predictions of behavioral sciences, metacognitive, negative affectivity, and mind–body interaction theories about the potential roles of implicit memory, depression, and worry in the incidence of CAD (Gordon & Hobbs, 2011; Jerry & James, 2005; Krantz & McCeney, 2002; Wells, 2009). In fact, depression, metacognitions, and implicit memory bias can be assumed to be three psychological risk factors that mediate mind–body interaction, and they could influence the incidence of CAD. This study supported the roles of depression, metacognitive worry, and negative-mood-inducing words as three indicators of cognitive impairments in patients with CAD. This study suggests that depression, metacognitions, and negative-mood-inducing implicit memory bias contain some types of cognitive distortions such as autonomous or unconscious schemas, revoking of negative-mood-congruent emotions, and dysfunctional knowledge. Therefore, these three constructs could produce cognitive impairments, and in turn they can increase the incidence of CAD. However, neutral-mood-inducing words as the indicator of fine cognitive functioning in the human memory system could reduce the risk of CAD.

Theoretically, this study suggests three potential explanations about the roles of depression, metacognition, and implicit memory bias on the incidence of CAD. First, it seems that depression, metacognitions, and implicit memory bias might play a major role in the incidence of CAD by increasing negative-mood-congruent emotion loads in the human memory system. Second, there is a probable comorbidity between CAD and GAD constructs, since anxiety, worry, and physical symptoms might influence the pathogenesis of GAD significantly (American Psychiatric Association, 2000). Third, it seems that the nature of mood problems and memory impairments in patients with CAD are substantially different from similar cognitive and emotional problems in patients without physical diseases such as CAD (Jordan, Bardé, & Zeiher, 2007). This explanation might show the personality characteristics of patients with CAD and their possible differences when compared with individuals without CAD (Rosen, 2007).

The results with regard to the second hypothesis indicated that depression and metacognition were positively correlated with negative-mood-inducing words. Also, depression and metacognition were negatively related to neutral-mood-inducing words. These findings are in line with Wells’s (2009) conceptualization in metacognition theory and its major role in mood regulation. According to metacognition theory, the efficiency of one’s memory is the main marker of metacognitive knowledge that refers to the beliefs and attitudes that people have about their own thinking (Wells, 2009). Therefore, metacognition about worry is the central mediator factor for explaining the roles of depression and implicit memory bias in the incidence of CAD. It seems that worry metacognitions are highly anxiety provoking, and it can predispose individuals for the pathogenesis of CAD in adulthood by creation of chronic and pathological worry in the earlier developmental stages. Anyway, the significant interrelatedness between depression, metacognitions, and implicit memory bias are congruent with predictions from the aforesaid conceptualizations in this study.

The results with regard to the third hypothesis in this study rejected the relationships of age and educational level to depression, metacognition, and implicit memory bias among men and women. The present findings for the roles of demographic factors in depression are incongruent with the previous literature. For example, studies indicated that demographics such as age, gender, and education can influence the impact of depression in cardiac disease (Polikandrioti et al., 2010). However, these findings about the nonsignificant roles of age and educational level in metacognitions among males and females are new in this study because there is a void of evidence in this field. Finally, the present study did not show significant roles of age and education status on implicit memory bias among both genders, which is inconsistent with some prior investigations (Zeitlin & McNally, 1991).

However, the present study is limited because of small sample size, relying on a single time period comparison and using self-rating measures for depression and metacognitions. In conclusion, the present study adds to the psychocardiology literature because of the significant higher levels of depression, metacognition, and implicit memory bias in patients with CAD; the exploration of interconnections between depression, metacognition, and implicit memory bias; and the rejection of age and educational status relationships to the aforesaid constructs in males and females. In practice, techniques for correction of autonomous and subconscious schemas, alteration of the negative-mood-congruent emotions, and change of dysfunctional knowledge can be used by clinicians in supportive and psychotherapeutic interventions for patients with CAD. These findings can be integrated with physical and mental health programs of CAD at community and clinical levels, particularly for males. Future research in the field of psychocardiology should examine the incidence of CAD longitudinally and cross-culturally with individuals diagnosed with CAD and those without CAD.

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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