A possible role of central dopamine metabolism associated with individual differences in locus of control

Reward-related self-agency is disturbed in depression and anxiety

BACKGROUND

The sense of agency, or the belief in action causality, is an elusive construct that impacts day-to-day experience and decision-making. Despite its relevance in a range of neuropsychiatric disorders, it is widely under-studied and remains difficult to measure objectively in patient populations. We developed and tested a novel cognitive measure of reward-dependent agency perception in an in-person and online cohort.

METHODS

The in-person cohort consisted of 52 healthy control subjects and 20 subjects with depression and anxiety disorders (DA), including major depressive disorder and generalized anxiety disorder. The online sample consisted of 254 participants. The task consisted of an effort implementation for monetary rewards with computerized visual feedback interference and trial-by-trial ratings of self versus other agency.

RESULTS

All subjects across both cohorts demonstrated higher self-agency after receiving positive-win feedback, compared to negative-loss feedback when the level of computer inference was kept constant. Patients with DA showed reduced positive feedback-dependent agency compared to healthy controls. Finally, in our online sample, we found that higher self-agency following negative-loss feedback was associated with worse anhedonia symptoms.

CONCLUSION

Together this work suggests how positive and negative environmental information impacts the sense of self-agency in healthy subjects, and how it is perturbed in patients with depression and anxiety.

Striatal dopamine D2 binding correlates with locus of control: Preliminary evidence from [11C]raclopride Positron Emission Tomography

The ability to exert control has been widely investigated as a hallmark of adaptive behaviour. Dopamine is recognized as the key neuromodulator mediating various control-related processes. The neural mechanisms underlying the subjective perception of being in control, or Locus of Control (LOC) are however less clear. LOC indicates the subjective tendency to attribute environmental outcomes to one's actions (internal LOC) or instead to external incontrollable factors (external LOC). Here we hypothesized that dopamine levels also relate to LOC. Previous work shows that dopamine signaling mediates learning of action-outcome relationships, outcome predictability, and opportunity cost. Prominent theories propose dopamine dysregulation as the key pathogenetic mechanism in schizophrenia and depression. Critically, external LOC is a risk factor for schizophrenia and depression, and predicts increased vulnerability to stress. However, a direct link between LOC and dopamine levels in healthy control had not been demonstrated. The purpose of our study was to investigate this link. Using [¹¹C]raclopride Positron Emission Tomography we tested the relationship between D2 receptor binding in the striatum and LOC (measured with the Rotter Locus of Control scale) in 15 healthy volunteers. Our results show a large and positive correlation: increased striatal D2 binding was associated with External LOC. This finding opens promising avenues for the study of several psychological impairments that have been associated with both dopamine and LOC, such as addiction, schizophrenia, and depression.

A Reward-Based Framework of Perceived Control

Perceived control can be broadly defined as the belief in one's ability to exert control over situations or events. It has long been known that perceived control is a major contributor toward mental and physical health as well as a strong predictor of achievements in life. However, one issue that limits a mechanistic understanding of perceived control is the heterogeneity of how the term is defined in models in psychology and neuroscience, and used in experimental settings across a wide spectrum of studies. Here, we propose a framework for studying perceived control by integrating the ideas from traditionally separate work on perceived control. Specifically, we discuss key properties of perceived control from a reward-based framework, including choice opportunity, instrumental contingency, and success/reward rate. We argue that these separate reward-related processes are integral to fostering an enhanced perception of control and influencing an individual's behavior and well-being. We draw on select studies to elucidate how these reward-related elements are implicated separately and collectively in the investigation of perceived control. We highlight the role of dopamine within corticostriatal pathways shared by reward-related processes and perceived control. Finally, through the lens of this reward-based framework of perceived control, we consider the implications of perceived control in clinical deficits and how these insights could help us better understand psychopathology and treatment options.

The longitudinal association between cognitive control capacities, suicidality, and depression during late adolescence and young adulthood

This study examined the association between cognitive control capacities, suicidal thoughts and attempts, and depressive symptoms during late adolescence and young adulthood. The sample included 4192 participants (55.5% female) from the United States who participated in Waves III (2001-2002; respondent age 18-26 years) and IV (2007-2008; respondent age 24-33 years) of the National Longitudinal Study of Adolescent to Adult Health. Data were analyzed using structural equation modeling. Suicidality in late adolescence predicted depressive symptoms in young adulthood. Depressive symptoms were not predictive of later suicide ideation nor attempts. Working memory was associated with lower depressive symptoms. Higher verbal ability was associated with more suicidal thoughts but not attempts. Internal locus of control was associated with decreased depressive symptoms and suicidal thoughts/attempts in young adulthood. Findings suggest that cognitive control capacities developed in adolescence differentially predict depressive symptoms, suicidal thoughts, and suicide attempts in young adulthood.

Dopamine, locus of control, and the exploration-exploitation tradeoff

Whether to continue to exploit a source of reward, or to search for a new one of potentially greater value, is a fundamental and underconstrained decision. Recent computational studies of this exploration-exploitation tradeoff have found that variability in exploration across individuals is influenced by a functional polymorphism (Val158Met) in the catechol-O-methyltransferase (COMT) gene, whose protein product degrades synaptically released dopamine. However, these and other genotype-phenotype associations have rarely been causally tested. To directly test this association and to evaluate additional behavioral characteristics, including perceived locus of control (LOC), here we used the COMT inhibitor tolcapone in a randomized, double-blind, counterbalanced, within-subject study of 66 subjects genotyped for the Val158Met allele to assess the hypothesis that reducing COMT enzymatic activity interacts with genotype to increase uncertainty-driven exploration. In keeping with our initial hypothesis, tolcapone led to an increase in exploratory, but not exploitative, behavior in Met/Met rather than Val/Val subjects. Independent of genotype, those subjects with a more external LOC also showed increases in uncertainty-driven exploration on tolcapone relative to placebo. However, we did not replicate our previous finding that Met/Met subjects show greater exploration at baseline. Together these findings support a model in which exploration is hypothesized to have a dopaminergic basis. Moreover, in keeping with findings in other behavioral and cognitive domains, the response to an increase in presumptively frontal dopamine is dependent upon baseline dopamine tone.

The role of the opioid system in alcohol dependence

The role of the brain opioid system in alcohol dependence has been the subject of much research for over 25 years. This review explores the evidence: firstly describing the opioid receptors in terms of their individual subtypes, neuroanatomy, neurophysiology and ligands; secondly, summarising emerging data from specific neurochemical, behavioural and neuroimaging studies, explaining the characteristics of addiction with a focus on alcohol dependence and connecting the opioid system with alcohol dependence; and finally reviewing the known literature regarding opioid antagonists in clinical use for alcohol dependence. Further interrogation of how modulation of the opioid system, via use of MOP (mu), DOP (delta) and KOP (kappa) agents, restores the balance of a dysregulated system in alcohol dependence should increase our insight into this disease process and therefore guide better methods for understanding and treating alcohol dependence in the future.

Externalized attributional bias in the Ultra High Risk (UHR) for psychosis population

Specific externalizing attributional biases appear to be common in early psychosis. They may represent trait risk factors for the later development of a psychotic disorder, yet few studies have investigated this in clinical "at risk" populations. We aimed to investigate one particular bias, the Locus of Control of reinforcement (LOC) in a "Ultra High Risk" (UHR) for psychosis group. We recruited UHR individuals from an established at risk clinical service and a community control group. LOC was measured using the Adult Nowicki Strickland Internal External scale (ANSIE). Neuropsychological functioning, social functioning and psychopathology were assessed. We analyzed data from 30 controls and 30 UHR individuals. The UHR sample had a significantly more externalized LOC (control for events perceived to be external to the person) than controls. This difference remained statistically significant after adjusting for covariates (age, gender and IQ). More externalized LOC scores were negatively correlated with social and occupational functioning scores in the control group but not in the UHR group and positively correlated with negative symptoms and paranoid symptoms in the UHR group. These findings have implications for identifying potential psychological vulnerabilities for the development of psychosis and informing treatment approaches within the at risk group.

Who Do You Think Is in Control in Addiction? A Pilot Study on Drug-related Locus of Control Beliefs

OBJECTIVES

The drug-related locus of control scale (DR-LOC) is a new instrument for assessing a person's belief of "being in control" in situations involving drug abuse. It consists of 16-item pairs presented in a forced-choice format, based on the conceptual model outlined by Rotter. The model characterizes the extent to which a person believes that the outcome of an event is under their personal control (internal locus of control) or the influence of external circumstances (external locus of control).

METHODS

A total of 592 volunteers completed the DR-LOC and the Rotter's I-E scale. Approximately half of the respondents were enrolled in a drug treatment program for opiates, stimulants and/or alcohol dependence (n = 282), and the remainder (n = 310) had no history of drug dependence.

RESULTS

Factor analysis of DR-LOC items revealed 2 factors reflecting control beliefs regarding (i) the successful recovery from addiction, and (ii) decisions to use drugs. The extent to which a person attributes control in drug-related situations is significantly influenced by their personal or professional experiences with drug addiction. Drug-dependent individuals have a greater internal sense of control with regard to addiction recovery or drug-taking behaviors than health professionals and/or non-dependent control volunteers.

CONCLUSIONS

The DR-LOC has shown to effectively translate generalized expectancies of control into a measure of control expectancies for drug-related situations, making it more sensitive for drug-dependent individuals than Rotter's I-E scale. Further research is needed to demonstrate its performance at discriminating between heterogeneous clinical groups such as between treatment-seeking versus non-treatment-seeking drug users.

[Self-perceived health, as an indicator of psychological well-being: behavioural epidemiological analysis among the adolescent population]

BACKGROUND

Self rated health is a widely used measure in behavioural epidemiological studies which is a global, informative indicator of health status and quality of life.

AIM

The main goal of the present study was to examine the relationship between subjective health status of adolescents with individual, psychological protective and risk factors.

METHOD

The authors performed the study among youth in Szeged, Hungary in the autumn of 2010. Data collection was based on self-administered questionnaires. 656 high school students were included in the sample. Logistic regression analyses were applied to detect associations including the individual, psychological indicators as dependent variables and self perceived health as an independent variable.

RESULTS

It was found that adolescents with better self perceived health had higher scale points of optimism and satisfaction with life, whereas lower self rated health correlated with higher values of depression and emotional aggression. There were gender differences in both protective and risk factors. Internal locus of control was a protective factor while depression, emotional aggression, and external locus of control were risk factors of psychological health among girls.

CONCLUSION

Self rated health can be a possible indicator of subjective well-being that may open a way to prevention in behavioural medicine.

Delay discounting, locus of control, and cognitive impulsiveness independently predict tobacco dependence treatment outcomes in a highly dependent, lower socioeconomic group of smokers

Tobacco use disproportionately affects lower socioeconomic status (SES) groups. Current explanations as to why lower SES groups respond less robustly to tobacco control efforts and tobacco dependence treatment do not fully account for this disparity. The identification of factors that predict relapse in this population might help to clarify these differences. Good candidates for novel prognostic factors include the constellation of behaviors associated with executive function including self-control/impulsiveness, the propensity to delay reward, and consideration and planning of future events. This study examined the ability of several measures of executive function and other key clinical, psychological, and cognitive factors to predict abstinence for highly dependent lower SES participants enrolled in intensive cognitive-behavioral treatment for tobacco dependence. Consistent with predictions, increased discounting and impulsiveness, an external locus of control as well as greater levels of nicotine dependence, stress, and smoking for negative affect reduction predicted relapse. These findings suggest that these novel factors are clinically relevant in predicting treatment outcomes and suggest new targets for therapeutic assessment and treatment approaches.

[The significance of the relationship between external/internal locus of control and adolescent substance use in behavioral medicine]

Prevention and treatment of the addictions are key public health priorities in modern society. In medical practice, in relation to the biochemical processes, mapping the addiction-prone personality traits, like external/internal locus of control are getting more and more attention. Individuals with high level on internal locus of control, for example, tend to take care of their health behavior; the lack of it, on the other hand, may worsen the effectiveness of stress release which may increase the likelihood of turning to substance use.

AIMS

The main goal of the present study was to investigate the relationship between adolescent substance use (both lifetime prevalence and the actual substance user status) and external/internal locus of control).

METHOD

The data collection of the questionnaire survey was going on among 656 high school students in Szeged (age range between 14-21 years, mean = 16.5 years, S.D. = 1.5 years of age, 49.1% of the sample was female). Associations between indicators of substance use (as dependent variables) and scale points of external/internal locus of control (as independent variables) were assessed using odds ratios calculated by logistic regression analyses, whereas gender was used as a controlling variable.

RESULTS

Among boys, scale points of external, among girls, those of internal locus of control showed higher values. External locus of control increased, whereas internal locus of control decreased the risk of substance use, however, the relative role of external/internal locus of control was different according to the type of substance use and the prevalence values. In terms of smoking, lifetime prevalence, whereas in terms of marijuana use, the actual user status was influenced. In addition, while the latter one was also affected by gender, it did not play a role at all in the previous one.

CONCLUSIONS

All these findings suggest that behavioral control may play a particularly important role in prevention of adolescent substance use. For developing this, methods of cognitive therapy would be effective to be completed with autogenic relaxation training as well.

Autistic spectrum disorders as functional disconnection syndrome

We outline the basis of how functional disconnection with reduced activity and coherence in the right hemisphere would explain all of the symptoms of autistic spectrum disorder as well as the observed increases in sympathetic activation. If the problem of autistic spectrum disorder is primarily one of desynchronization and ineffective interhemispheric communication, then the best way to address the symptoms is to improve coordination between areas of the brain. To do that the best approach would include multimodal therapeusis that would include a combination of somatosensory, cognitive, behavioral, and biochemical interventions all directed at improving overall health, reducing inflammation and increasing right hemisphere activity to the level that it becomes temporally coherent with the left hemisphere. We hypothesize that the unilateral increased hemispheric stimulation has the effect of increasing the temporal oscillations within the thalamocortical pathways bringing it closer to the oscillation rate of the adequately functioning hemisphere. We propose that increasing the baseline oscillation speed of one entire hemisphere will enhance the coordination and coherence between the two hemispheres allowing for enhanced motor and cognitive binding.

Increased perceived stress is associated with blunted hedonic capacity: potential implications for depression research

Preclinical studies suggest that stress exerts depressogenic effects by impairing hedonic capacity; in humans, however, the precise mechanisms linking stress and depression are largely unknown. As an initial step towards better understanding the association between stress and anhedonia, the present study tested, in two independent samples, whether individuals reporting elevated stress exhibit decreased hedonic capacity. The Perceived Stress Scale (PSS) measured the degree to which participants appraised their daily life as unpredictable, uncontrollable, and overwhelming. Hedonic capacity was objectively assessed using a signal-detection task based on a differential reinforcement schedule. Decreased reward responsiveness (i.e., the participants' propensity to modulate behavior as a function of reward) was used as an operational measure of hedonic capacity. In both Study 1 (n=88) and Study 2 (n=80), participants with high PSS scores displayed blunted reward responsiveness and reported elevated anhedonic symptoms. Additionally, PSS scores predicted reduced reward responsiveness even after controlling for general distress and anxiety symptoms. These findings are consistent with preclinical data highlighting links between stress and anhedonia, and offer promising insights into potential mechanisms linking stress to depression.

Endogenous opioid blockade and impulsive responding in alcoholics and healthy controls

The opioid receptor antagonist naltrexone (NTX) is one of few approved treatments for alcoholism, yet the mechanism by which it reduces drinking remains unclear. In rats, NTX reduces morphine-induced impulsive choice bias; however, nothing is known about the drug's effect on discrete aspects of impulsive behavior in humans, such as decision-making and inhibitory control. Here, we used a modified delay discounting procedure to investigate whether NTX improves decision-making or inhibitory control in humans. We measured the effect of acute NTX (50 mg) on choice between smaller sooner (SS) and larger later monetary rewards and on response errors (motor mismatch) in a high conflict condition in a group of abstinent alcoholics (AA) and healthy control subjects (CS). We previously reported that AA selected the SS option significantly more often than did CS in this paradigm. If the choice bias of AA is due to enhanced endogenous opioid signaling in response to potential reward, NTX should reduce such bias in the AA group. We found that NTX did not reliably reduce impulsive choice in the AA group; however, NTX's effect on choice bias across individuals was robustly predictable. NTX's effect on choice bias was significantly correlated with scores on Rotter's Locus of Control (LOC) scale; increasingly internal LOC scores predicted increasing likelihood of impulsive choices on NTX. In addition, we found that NTX significantly enhanced control of motor responses, particularly within the CS group. These results suggest that endogenous opioids may impair response selection during decision-making under conflict, and that NTX's effects on explicit decision-making are personality-dependent. Determining the biological basis of this dependence could have important implications for effective alcoholism treatment.

Spontaneous Eye Blink Rates vary according to individual differences in generalized control perception

This study tested the hypothesis that individual differences in generalized control perception for 43 undergraduate adults may be reflected in Spontaneous Eye Blink Rates during conversation in an interview. Control perception was assessed by means of Rotter's internal-external Locus of Control questionnaires, while Spontaneous Eye Blink Rates were computed from filmed videos of interviews consisting of a series of questions which could presumably have triggered different mental states. Pearson correlations and linear regression analyses indicated that the individual differences in Spontaneous Eye Blink Rates did not differ significantly across different questions, but that Spontaneous Eye Blink Rates measured over the entire interview correlated positively and significantly with an internal Locus of Control (r = .26). This could be interpreted as modest but corroborative evidence that a personality trait reflecting control perception may have a biological component. The possible roles of dopamine neurotransmission and frontal cortex involvement in higher cognition and Locus of Control are discussed.

On feeling in control: A biological theory for individual differences in control perception

This review aims to create a cross-disciplinary framework for understanding the perception of control. Although, the personality trait locus of control, the most common measure of control perception, has traditionally been regarded as a product of social learning, it may have biological antecedents as well. It is suggested that control perception follows from the brain's capacity for self regulation, leading to flexible and goal directed behaviours. To this account, a model is presented which spans several levels of analyses. On a behavioural level, control perception may be a corollary of emotion regulation, executive functions, and social cognition. On a neural level, these self-regulatory functions are substantiated in part by the dorsolateral and ventral prefrontal cortex and the anterior cingulate cortex. In addition, a possible role of subcortical-cortical dopamine pathways underlying control perception is discussed.

Prenatal influences on brain dopamine and their relevance to the rising incidence of autism

The incidence of autism has risen 10-fold since the early 1980s, with most of this rise not explainable by changing diagnostic criteria. The rise in autism is paradoxical in that autism is considered to be one of the most genetically determined of the major neurodevelopmental disorders and should accordingly either be stable or even declining. Because a variety of epigenetic influences, particularly those occurring during the prenatal period, can override or masquerade as genetic influences, these should be considered as prime contributors to the recent increase of autism. Prenatal influences on dopamine activity are especially well-documented, including the effects of maternal psychosocial stress, maternal fever, maternal genetic and hormonal status, use of certain medications, urban birth, and fetal hypoxia. All of these factors have been implicated in the genesis of autism, which is characterized by a "hyperdopaminergic" state based on evidence from monkey and human behavioral studies, pharmacological studies in humans, and a left-hemispheric predominance of both dopamine and autistic-like symptoms. Chronically high maternal levels of dopamine caused by the pressures of increasingly urbanized societies and by changing maternal demographics such as increased workforce participation, educational achievement level, and age at first birth, may be especially significant epigenetic contributors to the recent autism rise.

Does psychological characteristic influence physicians’ communication styles? Impact of physicians’ locus of control on interviews with a cancer patient and a relative

CONTEXT

Physicians' psychological characteristics may influence their communication styles and may thus interfere with patient-centred communication.

OBJECTIVE

Our aim was to test the hypothesis that, in interviews with a cancer patient and a relative, physicians with an "external" locus of control (LOC; who believe that life outcomes are controlled by external forces such as luck, fate or others) have a communication style different from that of physicians with an "internal" LOC (who believe that life outcomes are controlled by their own characteristics or actions).

DESIGN, SETTING, PARTICIPANTS AND INTERVENTION

Eighty-one voluntary physicians practising in the field of oncology were recorded while performing an actual and a simulated interview with a cancer patient and a relative.

MAIN OUTCOME MEASURES

Physicians' communication skills were assessed using the Cancer Research Campaign Workshop Evaluation Manual. Physicians' LOC was assessed using the Rotter I-E scale. The communication skills of the upper and lower quartiles of physicians in respect of their scores on this scale were compared using Student's t test.

RESULTS

In actual interviews, physicians with an "external" LOC talked more to the relative (P=0.017) and used more utterances with an assessment function (P=0.010) than physicians with an "internal" LOC. In simulated interviews, physicians with an "external" LOC used less utterances that give premature information (P=0.031) and used more utterances with a supportive function, such as empathy and reassurance (P=0.029), than physicians with an "internal" LOC.

CONCLUSION

These results provide evidence that physicians' LOC can influence their communication styles. Physicians' awareness of this influence constitutes a step towards a tailoring of their communication skills to every patient's and relative's concerns and needs and thus towards a patient-centred communication.