Luther2016.pdf

Psychiatry Research 245 (2016) 172–178

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Metacognition deficits as a risk factor for prospective motivation deficits in schizophrenia spectrum disorders Lauren Luther a,n, Ruth L. Firmin a, Kyle S. Minor a, Jenifer L. Vohs b,c,d, Benjamin Buck e, Kelly D. Buck f, Paul H. Lysaker b,f a

Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States Indiana University School of Medicine, Indianapolis, IN, United States c Prevention and Recovery Center for Early Psychosis, Midtown Community Mental Health Centers, Eskenazi Hospital, Indianapolis, IN, United States d Larue D. Carter Memorial Hospital, IU Psychotic Disorders Research Program, Indianapolis, IN, United States e University of North Carolina at Chapel Hill, Chapel Hill, NC, United States f Richard L. Roudebush Veteran's Affairs Medical Center, Indianapolis, IN, United States b

art ic l e i nf o

a b s t r a c t

Article history: Received 27 March 2016 Received in revised form 5 August 2016 Accepted 8 August 2016 Available online 9 August 2016

Although motivation deficits are key determinants of functional outcomes, little is known about factors that contribute to prospective motivation in people with schizophrenia. One candidate factor is metacognition, or the ability to form complex representations about oneself, others, and the world. This study aimed to assess whether metacognition deficits were a significant predictor of reduced prospective motivation, after controlling for the effects of baseline motivation, anticipatory pleasure, and antipsychotic medication dose. Fifty-one participants with a schizophrenia spectrum disorder completed measures of metacognition and anticipatory pleasure at baseline; participants also completed a measure of motivation at baseline and six months after the initial assessment. Baseline antipsychotic dose was obtained from medical charts. Hierarchical regression analysis revealed that lower levels of baseline metacognition significantly predicted reduced levels of motivation assessed six months later, after controlling for baseline levels of motivation, anticipatory pleasure, and antipsychotic dose. Higher baseline antipsychotic dose was also a significant predictor of reduced six month motivation. Results suggest that metacognition deficits and higher antipsychotic dose may be risk factors for the development of motivation deficits in schizophrenia. Implications include utilizing interventions to improve metacognition in conjunction with evaluating and possibly lowering antipsychotic dose for people struggling with motivation deficits. & 2016 Elsevier Ireland Ltd. All rights reserved.

Key words: Schizophrenia Motivation Metacognition Antipsychotic medication Anticipatory pleasure

1. Introduction Although motivation, which can generally be defined as an internal state that initiates, directs, and maintains goal-directed behavior (Kleinginna and Kleinginna, 1981), has long been a focus of psychological theories and research (Maslow, 1943), it has only recently gained momentum as an important area of schizophrenia research. To date, motivation deficits in schizophrenia are generally conceptualized as largely falling under the umbrella of negative symptoms (American Psychiatric Association, 2013), and research has found that motivation deficits represent a key negative symptom subdomain (Blanchard and Cohen, 2006; Lincoln et al., in press). Further, research has demonstrated that n Correspondence to: IUPUI School of Science, Department of Psychology, LD 124, 402 N. Blackford St., Indianapolis, IN 46202, United States. E-mail address: [email protected] (L. Luther).

http://dx.doi.org/10.1016/j.psychres.2016.08.032 0165-1781/& 2016 Elsevier Ireland Ltd. All rights reserved.

motivation is frequently impaired in schizophrenia (Cooper et al., 2015; Luther et al., 2015a) and that these deficits play a critical role in reduced treatment response (Medalia and Saperstein, 2011), learning (Choi and Medalia, 2010; Tas et al., 2012) and functioning (Foussias et al., 2009, 2011). Several studies have also found that motivation mediates the relationship between both symptoms and functional outcomes (Yamada et al., 2010) and cognitive deficits and functional outcomes (Nakagami et al., 2008; Gard et al., 2009; Fervaha et al., 2015a). Despite increasing evidence that motivation is a key determinant of functional outcomes in schizophrenia, there is limited empirical research investigating prospective determinants of motivation; thus, risk factors for motivation impairments have not been fully identified. Identifying risk factors for these deficits is critical in order to establish novel treatment targets. This is especially salient given the modest improvement seen in motivational deficits with many existing psychological and pharmacological treatments in people with schizophrenia (Kirkpatrick et al.,

L. Luther et al. / Psychiatry Research 245 (2016) 172–178

2006; Velthorst et al., 2015). Further, discerning factors that lead to improved treatments can serve to impede motivational declines that may occur as the course of schizophrenia progresses (Luther et al., 2015a). One characteristic that has been argued to play a role in the emergence of motivation impairments is deficits in metacognition or impairments in the capacity to integrate mental experiences into complex representations. The term metacognition was originally used in the education literature (Flavell, 1979), but it has subsequently been used in the context of psychopathology research to describe a spectrum of mental experiences, ranging from reflections about more discrete mental experiences (e.g., explicit thoughts and feelings), to more synthetic reflective acts where intentions, thoughts, feelings, and connections between experiences are continuously evolving into integrated representations of oneself and others as distinct agents in the world (Semerari et al., 2003; Lysaker et al., 2013). Metacognition is viewed as partly overlapping with social cognition but diverges in that it focuses not on the accuracy of a single social cue, such as determining whether a thought or feeling is correct, but on the degree to which mental experiences about the self and others are coherently integrated (Lysaker et al., 2015c). Notably, individuals with early and prolonged schizophrenia have demonstrated unique deficits in metacognition compared to healthy controls (Hasson-Ohayon et al., 2015) as well as those with substance use disorders (Lysaker et al., 2014; Wasmuth et al., 2015), bipolar disorder (Tas et al., 2014), and post-traumatic stress disorder (Lysaker et al., 2015a). Metacognition may be a strong candidate predictor of motivation for several reasons. First, possessing an integrated sense of oneself and others likely guides goal-directed behavior by providing meaning and value to completing tasks or activities. Thus, when faced with tasks, a person without intact metacognitive capacities to make sense of and provide meaning to these tasks will likely have trouble evaluating and expending the effort required to complete them. Second, goal-directed behavior may be contingent on being able to view oneself as a unique agent in the world who is capable of initiating actions and responding to challenges. Indeed, metacognition has been argued to play a critical role in cultivating an individual's sense of agency (Lysaker et al., 2008a, 2013). Specifically, when faced with problems or new experiences, without an integrated sense of oneself and others to make sense of and to respond to problems and new experiences, a person may become increasingly confused or overwhelmed and may withdraw or discontinue any associated activities to reduce confusion. Over time, without intact metacognitive capacities to guide and provide meaning to behavior, one would likely be at risk for reductions in goal-directed behavior. Evidence supporting the connection between metacognition and motivation includes findings from recent cross-sectional and longitudinal studies demonstrating a relationship between metacognitive deficits and reduced motivation and overall negative symptoms. Specifically, Tas et al. (2012) demonstrated that reduced metacognition was associated with lower concurrent motivation, while other studies have shown that metacognition deficits are related to increased concurrent and prospective negative symptoms (Hamm et al., 2012; MacBeth et al., 2014; Rabin et al., 2014; Lysaker et al., 2015b). Further, lower levels of metacognition have been found to be a significant predictor of reduced levels of concurrent motivation (Luther et al., 2016) and increased levels of negative symptoms both six and twelve months later (McLeod et al., 2014). Similarly, Vohs and Lysaker (2014) reported that in those with prolonged schizophrenia engaged in a treatment trial, participants with lower levels of mastery, a domain of metacognition, had consistently lower monthly ratings of motivation than those with higher levels of mastery over a period of six months. Taken together, these findings are also consistent with Bleuler's

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(1911/1950) formulation of schizophrenia where he described that people with schizophrenia experience a disturbance in the associative processes that are needed to integrate information and to support meaningful goal-directed behavior. This study sought to extend the findings of Vohs and Lysaker (2014) by examining how a wider range of metacognition domains was related to motivation over time in a sample that was not engaged in a treatment trial. Specifically, we employed a more comprehensive measure of metacognition to assess whether metacognitive deficits are a potential risk factor for reduced motivation over time in a sample of fifty-one people with a schizophrenia spectrum disorder. We predicted that reduced levels of metacognition would predict lower levels of motivation six months later even after controlling for baseline levels of motivation. Further, although difficulty anticipating rewarding outcomes has been thought to impact motivation in schizophrenia (Gard et al., 2007; Barch et al., 2015), it remains to be established whether anticipatory pleasure and motivation are empirically linked over time and importantly, whether metacognition deficits account for reduced prospective motivation above and beyond the effects of anticipatory pleasure deficits. Thus, we included a measure of anticipatory pleasure to rule out the possibility that reduced anticipatory pleasure accounted for deficits in motivation to a greater extent than metacognition deficits. Similarly, as demographic factors such as age, education, and gender (Faerden et al., 2010; Choi et al., 2014) as well as antipsychotic medication dose (Kirsch et al., 2007; Mas et al., 2013) and psychiatric symptoms (Yamada et al., 2010; Luther et al., 2016) have been linked to motivation, we included measures of these variables as potential covariates. We also included a measure of consummatory pleasure to explore its relationship with prospective motivation.

2. Methods 2.1. Participants Fifty-one participants with SCID-confirmed (First et al., 2002) diagnoses of schizophrenia (n ¼ 26) or schizoaffective disorder (n ¼25) were recruited from either a Veterans' Affairs Medical Center (n ¼45) or a community mental health center (n ¼6) for a longitudinal study examining the correlates of metacognition in people with a schizophrenia spectrum disorder. Participants were in a post-acute phase of illness as defined by no hospitalizations or changes in housing or medication within 30 days of study enrollment. Exclusion criteria also included active substance dependence or developmental disability, as determined through a chart review. Twenty-nine participants were taking a single antipsychotic medication (25 atypical, 4 typical antipsychotics), while 16 patients were taking multiple antipsychotics (8 taking one atypical and one typical, 7 taking two atypical, 1 taking two typical antipsychotics). Antipsychotics included aripiprazole, clozapine, fluphenazine, haloperidol, loxapine, olanzapine, quetiapine, risperidone, trifluoperazine, and ziprasidone. Six participants were not taking any antipsychotic medication. There were no significant changes in medication doses (i.e., chlorpromazine equivalent doses) or any hospitalizations during the course of the study. Participants were primarily male, African American, and were enrolled in outpatient treatment. Full demographic information is reported in Table 1. 2.2. Measures 2.2.1. Metacognition Metacognition was assessed with a two-step process. First, the Indiana Psychiatric Illness Interview (IPII; Lysaker et al., 2002) was

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Table 1 Means, standard deviations, and correlations between baseline demographic and clinical variables and baseline and six-month follow-up motivation. Baseline Variables

Demographic variables Age Education (years) Gender (n, % male)a Race (n, % African American)a Parent education (years)b Illness duration (years)ce:b,c Lifetime psychiatric hospitalizations Chlorpromazine equivalent dosesb,d

Mean (SD)

50.43 (7.43) 12.75 (1.60) 45 (88%) 26 (51%) 12.00 (2.54) 25.40 (9.00) 8.47 (8.27) 568.70 (567.96)

Clinical variables QLS Index – Motivation 6.16 (2.78) TEPS – Anticipatory pleasure 41.06 (7.88) TEPS – Consummatory pleasure 35.04 (6.34) PANSS – Positive symptoms 16.59 (4.66) PANSS – Negative symptoms 18.75 (5.56) PANSS – Cognitive symptoms 17.39 (4.42) PANSS – Hostility symptoms 7.78 (2.63) PANSS – Emotional discomfort 12.51 (3.84) symptoms MAS-A – Metacognition total 11.68 (4.53)

Correlations with Motivation Baseline

Six-month

0.06 0.01 0.00  0.14 0.01 0.18  0.22

 0.02 0.22 0.15 0.02  0.12  0.05  0.17

 0.15

 0.34*

– 0.09 0.06  0.36*  0.41**  0.31*  0.11  0.23

0.32* 0.27*  0.01  0.14  0.16  0.26 0.05 0.04

0.55**

0.40**

PANSS ¼Positive and Negative Syndrome Scale; MAS-A ¼Metacognition Assessment Scale-Abbreviated; TEPS ¼Temporal Experience of Pleasure Scale; QLS Index ¼Quality of Life Scale Motivation Index. *

p r 0.05. po 0.01. a Point-biseral correlations. Positive number indicates women and African Americans tend to score higher. b Parent education missing n ¼1; illness duration missing n ¼3; chlorpromazine equivalent doses missing n¼4. c Based on age at first psychiatric hospitalization. d Chlorpromazine equivalents were calculated using Woods (2003) and Lehman et al. (2004). **

used to assess how participants understood their experience with mental illness. The IPII is a semi-structured interview that typically lasts between 30 and 60 min and is broken into five main sections, with interviewers asking the participants to discuss: 1) their life story, 2) whether they believe they have a mental illness, and if so, whether it has affected different facets of living (e.g., relationships) 3), whether, and if so, how their illness controls and is controlled by them, 4) how their illness affects and is affected by others, and 5) what they anticipate in the future. The IPII interview is recorded and transcribed, and responses are rated for metacognitive capacity using the Metacognition Assessment Scale-Abbreviated (MASA; Lysaker et al., 2005). The MAS-A was adapted from the Metacognitive Assessment Scale (Semerari et al., 2003) in order to assess metacognitive capacities that spontaneously appear within the IPII. For the current investigation, we used the total MAS-A score, which is the sum of its four subscales: 1) the ability to think about and integrate information about one's mental states or selfreflectivity (score range 0–9), 2) the ability to think about and integrate information about other people's mental states or awareness of the other's mind (range 0–7), 3) the ability to recognize that one is not the center of others’ mental states and intentions or decentration (range 0–3), and 4) the capacity to use knowledge about oneself and others to respond to psychological and social challenges or mastery (range 0–9). Higher scores reflect greater metacognitive capacity (total score range 0–28). The MAS-A total score has exhibited validity with measures of cognitive and clinical

insight (Lysaker et al., 2005, 2008b) and similar to previous studies (Lysaker et al., 2005; Rabin et al., 2014), demonstrated good interrater reliability in the current sample (intraclass correlations ranging from 0.71 to 0.91). 2.2.2. Motivation Motivation was assessed using the sum of three items from the clinician-rated Heinrichs-Carpenter Quality of Life Scale (QLS; Heinrichs et al., 1984): sense of purpose, degree of motivation, and curiosity. This scale was originally devised by Nakagami et al. (2008) as an index of intrinsic motivation, which can be generally thought of as engaging in a task or action because it is enjoyable or interesting (Ryan and Deci, 2000); however, a recent investigation by Choi et al. (2014) concluded that this index may more aptly measure general trait-like motivation that is not limited to a specific activity but encompasses one's typical level of motivation for a diverse range of activities, including novel activities or those aimed at self-improvement as well as activities of daily living. Thus, in the current investigation, we refer to this as an index of general trait-like (i.e., not limited to a specific task) motivation. The three items that comprise the motivation index are part of the intrapsychic foundations subscale of the QLS and are rated on a 7-point scale, with higher scores indicating greater motivation. The motivation index has been used in numerous studies with schizophrenia samples (c.f., Gard et al., 2009; Vohs et al., 2013; Choi et al., 2014; Luther et al., 2015a) and has demonstrated adequate discriminant validity, predictive validity, internal consistency, and test-retest reliability (Fervaha et al., 2015c; Nakagami et al., 2008, 2010; Saperstein et al., 2011). Good inter-rater reliability (intraclass correlation ¼0.88) was found in the current study. 2.2.3. Anticipatory and consummatory pleasure The 18-item Temporal Experience of Pleasure Scale (TEPS; Gard et al., 2006) was used to assess self-reported anticipatory and consummatory pleasure. Ten items comprise the anticipatory pleasure subscale (e.g., “When ordering something off the menu, I imagine how good it will taste”), and eight items compose the consummatory pleasure subscale (e.g., A hot cup of coffee or tea on a cold morning is very satisfying to me”). Items are rated on a 6-point scale, with higher scores suggesting greater anticipatory pleasure or consummatory pleasure, respectively. The TEPS scores have demonstrated good convergent validity with reward responsiveness and openness to different experiences (Gard et al., 2006) and had acceptable internal consistency in the current sample (α for anticipatory pleasure¼0.68; α for consummatory pleasure ¼0.67). 2.2.4. Symptoms Positive, negative, cognitive, hostility, and emotional discomfort symptoms were assessed by factor-analytically derived subscales (Bell et al., 1994) of the Positive and Negative Syndrome Scale (PANSS; Kay et al., 1987). Items are rated on a 7-point scale by trained clinicians following a chart-review and semi-structured interview. Higher scores are reflective of greater symptom severity. Good inter-rater reliability was found in the current study, with intra-class correlations ranging from 0.84 to 0.93. 2.3. Procedure After participants provided written informed consent, participants' diagnoses were confirmed by clinical psychologists using the SCID. At the baseline visit, participants completed the QLS, TEPS, PANSS, and IPII, and current antipsychotic doses were obtained from the participants’ medical chart. Participants also completed the QLS again approximately six months later. There

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was no experimental intervention between assessments. All assessments were completed with a trained (inter-rater reliability 40.70 on all study measures) Master's-level research assistant. MAS-A raters were blind to all other testing. Study procedures were approved by the local Institutional Review Board.

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Table 2 Hierarchical linear regression predicting motivation at six-month follow-up. R2 Step one QLS Index – Baseline motivation

0.15

Step two QLS Index – Baseline motivation Chlorpromazine equivalent doses TEPS – Anticipatory pleasure

0.25

Step three QLS Index – Baseline motivation Chlorpromazine equivalent doses TEPS – Anticipatory pleasure MAS-A Total – Metacognition

0.32

β

B

SE B

0.38

0.14

0.33 0.00 0.05

0.13 0.00 0.05

0.33*  0.26 0.14

0.17 0.00 0.04 0.19

0.15 0.00 0.05 0.09

0.17  0.28* 0.11 0.31*

R2 change 0.15**

0.38**

2.4. Analyses Analyses were conducted in several stages. First, we conducted Pearson and point-biseral correlations between both demographic variables and clinical measures (i.e., anticipatory and consummatory pleasure, symptoms, and metacognition) and motivation at baseline and six-month follow-up to examine the pattern of associations and importantly, to identify any baseline variables with significant associations with motivation at six-month followup; baseline variables with significant associations with motivation at follow-up were controlled for in regression analyses. Next, paired t-tests were conducted to examine whether scores on clinical measures changed between baseline and six-month follow-up. To test our hypothesis that baseline deficits in metacognition are a significant risk factor for prospective reduced motivation, we conducted a hierarchical linear regression predicting the QLS motivation index at six-month follow-up. The baseline score of the QLS motivation index was entered into the first step of the regression to control for baseline levels of motivation. Any baseline demographic variables or clinical measures that demonstrated significant associations with motivation at six-month follow-up were entered into the second step of the regression in order to control for the effects of these variables on motivation at six-month follow-up. Finally, the MAS-A total score was entered into the third step of the regression.

3. Results Means and standard deviations for all study variables are reported in Table 1. No significant changes were observed between baseline and six months scores on measures of motivation, anticipatory and consummatory pleasure, symptoms, and metacognition (all ps 4 0.05). However, 21 (41%) participants demonstrated at least one standard deviation change in motivation scores between baseline and six month assessments. 3.1. Correlations between motivation and demographic and clinical variables All correlations with baseline and six month motivation are reported in Table 1. Baseline motivation was not significantly associated with any demographic variables; however, reduced baseline motivation was significantly associated with increased baseline positive, negative, and cognitive symptoms, as well as lower metacognition. Decreased motivation at six-month followup was significantly associated with higher baseline chlorpromazine equivalent doses and decreased baseline motivation, anticipatory pleasure, and metacognition; accordingly, chlorpromazine equivalent doses and anticipatory pleasure were controlled for in the regression analysis. 3.2. Regression predicting prospective motivation Table 2 contains the results from the hierarchical linear regression analysis predicting motivation at six-month follow-up. In the first step, baseline motivation was entered, resulting in a significant model, F(1,45) ¼7.76, p ¼0.008. In this model, baseline motivation was a significant predictor of increased six month motivation and accounted for 15% of the variance in prospective

0.10

0.07*

Abbreviations are listed in Table 1. * **

p o0.05. p o 0.01.

motivation. In the second step, chlorpromazine equivalent doses and anticipatory pleasure were entered, which resulted in a significant model as well, F(3,43) ¼4.74, p ¼0.006, that accounted for 25% of the variance in six month motivation; however, the 10% increase in variance accounted for was only trending towards a significant increase over the model with baseline motivation (FΔ (2,43) ¼2.90, p ¼0.07). Baseline motivation was the sole significant predictor of six month motivation in step two. Finally, metacognition was entered in the third step, which again resulted in a significant model, F(4,42) ¼ 4.92, p ¼0.002, that accounted for 32% of the variance in six month motivation. The 7% increase in variance accounted for over the model with baseline motivation, chlorpromazine equivalent doses, and anticipatory pleasure (Step 2) was a statistically significant model improvement (FΔ (1,42) ¼ 4.37, p¼ 0.04). Reduced metacognition and greater chlorpromazine equivalent doses significantly predicted lower motivation in the third step.

4. Discussion Several studies have demonstrated that motivation deficits are among the strongest predictors of poor functioning in schizophrenia (Foussias et al., 2009, 2011; Fervaha et al., 2014); however, few studies have investigated factors that promote and sustain motivation over time in schizophrenia. Therefore, the primary aim of this study was to investigate the role of one candidate contributor, metacognition. Consistent with our hypothesis, impaired baseline metacognition predicted reduced prospective motivation, even after statistically accounting for the effects of baseline levels of motivation, anticipatory pleasure, and antipsychotic medication dose. Although a previous study has linked reduced metacognition to prospective motivation impairments (Vohs and Lysaker, 2014), the present study is the first to demonstrate the importance of metacognition deficits and antipsychotic doses on prospective motivation above and beyond the effects of anticipatory pleasure. One possible interpretation of these findings is that deficits in metacognition may foster or be a risk factor for deficits in motivation. Specifically, without a complex representation of oneself and others, a person may naturally experience less drive over time to engage in goal-directed behavior. This hypothesis is consistent with Bleuler's (1911/1950) original model of schizophrenia which suggested that a core element of the disorder is a disturbance in the associative processes needed to integrate information and to

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facilitate purposeful goal-directed behavior. Further, it is also consistent with the notion that motivational deficits in schizophrenia are due to problems forming mental representations that allow for reflection about the value and pleasure associated with a task (Heerey and Gold, 2007; Gold et al., 2008). Importantly, however, rival hypotheses cannot be ruled out, including the possibility that other variables not measured here may be more powerful determinants of prospective motivation. For example, given that studies have found associations between defeatist beliefs and increased negative symptoms (Grant and Beck, 2009; Luther et al., 2015b) and reduced effort allocation (Granholm et al., in press), future studies should also compare the relative contribution of defeatist beliefs to prospective motivation. Further, future studies may also want to consider the relationship between motivation and developmental processes, with particular consideration for the dialectical relationship between one's self-definition and sense of relatedness to others (Blatt and Blass, 1996; Guisinger and Blatt, 1994; McAdams, 1988) and how this relationship relates to the development and maintenance of motivation in people with schizophrenia. Importantly, there was no evidence that the relationship between motivation and metacognition was an artifact of the influence of deficits in anticipatory pleasure. Although previous crosssectional studies have found that reductions in anticipatory pleasure are linked to reduced concurrent levels of approach motivation (Gard et al., 2007) and negative symptoms (Favrod et al., 2009; but also see Strauss et al., 2011), this study extends previous studies by examining the relationship between anticipatory pleasure and motivation over time. We found that baseline levels of anticipatory pleasure were moderately and significantly correlated with motivation assessed six months later; however, anticipatory pleasure was not a significant predictor of six month motivation after statistically accounting for baseline motivation, metacognition, and antipsychotic dose. These findings suggest that impairments in forming a complex representation of oneself and others may be a stronger psychological determinant than difficulties anticipating future pleasure in the development of motivation deficits in people with schizophrenia. Thus, interventions aimed at reducing or preventing further motivation deficits in schizophrenia may benefit from targeting metacognition deficits prior to or in addition to anticipatory pleasure deficits. Unexpectedly, we found that increased baseline levels of antipsychotic doses were not significantly related to decreased motivation at baseline but that increased baseline levels of antipsychotic doses were significantly and moderately correlated with decreased motivation assessed six months later. However, the cross-sectional finding is consistent with Insel et al. (2014) and Fervaha et al. (2015b) who did not observe a relationship between concurrent antipsychotic doses and clinician-rated motivation. Further, we observed that baseline antipsychotic doses also remained a significant predictor of prospective motivation even when statistically accounting for the effects of baseline motivation, anticipatory pleasure, and metacognition. This finding contrasts a recent study that found that antipsychotic dose was not a significant predictor of motivation assessed six months later (Fervaha et al., 2015c). However, this discrepant finding may be due to the fact that Fervaha et al. (2015c) examined participants who were administered one form of antipsychotic medicine while many participants in the current sample were prescribed more than one antipsychotic. Our findings are also in line with Harrow and Jobe (2007) who found that after initial improvements from antipsychotic medications, people who stayed on antipsychotics over a 15 year period had fewer periods of recovery and worse global functioning than those who were off antipsychotics over the same period; thus, it may be that while antipsychotic medication can help initially with reductions in symptoms and improvements in

functioning, they may negatively impact recovery-related domains, such as motivation, over time. Further, it may be that for some, taking greater antipsychotic medication doses may dampen internal or emotional states (Buck et al., 2013; Mizrahi et al., 2007) that contribute to motivated behavior as well as support negative illness appraisals (e.g., feeling reduced personal control over one's illness), which can adversely impact one's sense of self and in turn lead to reductions in motivation over time. Future longitudinal work looking at the impact of taking antipsychotic medications on motivation and associated processes is needed in order to clarify the impact of antipsychotic medication on motivation over time in individuals with schizophrenia. There are additional unexpected findings. For instance, we found that baseline motivation accounted for only 15% of the variance in motivation at six-month follow-up. However, this finding is consistent with previous studies that have found that motivation is malleable over time (Faerden et al., 2010; Nakagami et al., 2010; Choi et al., 2013), and our findings also suggest that metacognition is a stronger predictor of prospective motivation than baseline motivation. We also found that baseline negative symptoms were significantly correlated with concurrent motivation but not prospective motivation. However, this may be due to the fact that the negative symptom measure used, the PANSS, did not fully assess the motivational subdomain of negative symptoms (Blanchard et al., 2010) or that the PANSS negative symptom subscale and the QLS motivation index are assessing slightly divergent constructs (Fervaha et al., 2015c). Alternatively, it may be that the negative symptom subdomains of motivation deficits and expressive deficits are related to separate underlying processes (Kirkpatrick et al., 2011) that are differentially affected over time. Future research could replicate these findings using novel instruments of negative symptoms such as the Brief Negative Symptom Scale (Strauss et al., 2012) or the Clinical Assessment Interview for Negative Symptoms (Horan et al., 2011). There are also a number of limitations that should be considered when interpreting these findings. First, the sample was relatively small and consisted largely of men with prolonged schizophrenia who were in a post-acute, stable phase of their disorder. Therefore, it may be that different correlates or predictors of motivation may exist in females, those that are experiencing early signs of schizophrenia, or those in a more acute phase of the illness. Second, this study did not include a measure of neurocognition; however, findings regarding the link between motivation and neurocognition have been mixed (c.f., Choi et al., 2014), demonstrating the need for future work in this area. Third, while a strength of this study was that metacognition was assessed across multiple domains, future research should investigate whether specific metacognitive domains are differentially predictive of prospective motivation. Further, although motivation in schizophrenia has been found to be dynamic over time (Nakagami et al., 2010), in light of the moderate correlation between baseline and six-month follow-up motivation observed in this study, additional psychometric investigations are needed to examine the QLS motivation index's test-retest reliability and utility as a repeated measure. Also, given that some previous work has found limited convergence between self-report and clinician-rated motivation (Choi et al., 2014; Cooper et al., 2015) and other clinical domains (Hasson-Ohayon et al., 2011) in schizophrenia samples, future work should seek to replicate these findings using a selfreport measure of motivation, such as the Intrinsic Motivation Inventory for Schizophrenia Research (Choi et al., 2010). Lastly, although a six month interval is of interest to clinical work focused on metacognition and motivation, it may be the case that different relationships exist when examining periods of time longer than six months. In summary, our findings add to the increasing evidence that

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metacognition is a key psychological determinant of motivation and also suggest that antipsychotic doses may play an important role in prospective motivation in schizophrenia. Further, with replication, our findings may have several important clinical implications. First, our findings suggest that psychological treatments aiming to alleviate motivation deficits could benefit from incorporating metacognition as a treatment target. Specifically, integrated interventions (c.f., Lysaker et al., 2010; Harder and Folke, 2012; Bargenquast and Schweitzer, 2014; Brent et al., 2014) that promote a complex understanding of oneself and others may be well suited to address the phenomenon that promotes motivation deficits, and these interventions may even have a protective effect against the worsening of motivation deficits over time. Second, our findings suggest that it may be helpful for clinicians to consider the role of antipsychotic doses in individuals who demonstrate motivation impairments. Perhaps in concert with interventions aimed at targeting and improving metacognitive capacity, clinicians could consider that antipsychotic doses could be reduced, which may even further affect motivation deficits.

Conflicts of interest None.

Acknowledgement We would like to thank the people who participated in this research.

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