A randomized, double-blind, placebo-controlled study of light therapy for antepartum depression.

OBJECTIVE: Affective disorder during pregnancy is a common condition requiring careful judgment to treat the depression while minimizing risk to the fetus. Following up on promising pilot trials, we studied the efficacy of light therapy. METHOD: Twenty-seven pregnant women with nonseasonal major depressive disorder according to DSM-IV (outpatients, university polyclinic) were randomly assigned to 7,000 lux fluorescent bright white or 70 lux dim red (placebo) light administered at home in the morning upon awakening for 1 h/d in a 5-week double-blind trial carried out between October 2004 and October 2008. Clinical state was monitored weekly with the 29-item Structured Interview Guide for the Hamilton Depression Rating Scale (HDRS) with Atypical Depression Supplement (SIGH-ADS). Changes of rating scale scores over time were analyzed with the general linear model. Differences from baseline of SIGH-ADS and 17-item HDRS scores at every time point were the dependent variables, time was the within-subjects factor, and treatment was the between-subjects factor. The model also included baseline score of depression and gestational age at intervention start. RESULTS: The superiority of bright light over dim light placebo was shown for both SIGH-ADS (R² = 0.251; F(3,23) = 3.91; P < .05) and HDRS (R² = 0.338; F(3,23) = 5.42; P < .01) when analyzing the week-by-week change from baseline, and HDRS scores showed a significant interaction of treatment with time (F(4,92) = 2.91; P < .05). Categorical analysis revealed that the response rate (HDRS ≥ 50% improvement) at week 5 was significantly greater for bright light (81.3%, n = 16) than for placebo light (45.5%, n = 11) (P < .05). Remission (final score ≤ 8) was attained by 68.6% versus 36.4%, respectively (P < .05). Expectation ratings did not differ significantly between groups. CONCLUSIONS: Bright white light treatment for 5 weeks improved depression during pregnancy significantly more than placebo dim red light. The study provides evidence that light therapy, a simple, cost-effective antidepressant modality with minimal side effects for the mother and no known risk for the unborn child, may be a useful nonpharmacologic approach in this difficult situation. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01043289.

Neural substrates of reward magnitude, probability, and risk during a wheel of fortune decision-making task.

Economic decision-making involves the weighting of magnitude and probability of potential gains/losses. While previous work has examined the neural systems involved in decision-making, there is a need to understand how the parameters associated with decision-making (e.g., magnitude of expected reward, probability of expected reward and risk) modulate activation within these neural systems. In the current fMRI study, we modified the monetary wheel of fortune (WOF) task [Ernst, M., Nelson, E.E., McClure, E.B., Monk, C.S., Munson, S., Eshel, N., et al. (2004). Choice selection and reward anticipation: an fMRI study. Neuropsychologia 42(12), 1585-1597.] to examine in 25 healthy young adults the neural responses to selections of different reward magnitudes, probabilities, or risks. Selection of high, relative to low, reward magnitude increased activity in insula, amygdala, middle and posterior cingulate cortex, and basal ganglia. Selection of low-probability, as opposed to high-probability reward, increased activity in anterior cingulate cortex, as did selection of risky, relative to safe reward. In summary, decision-making that did not involve conflict, as in the magnitude contrast, recruited structures known to support the coding of reward values, and those that integrate motivational and perceptual information for behavioral responses. In contrast, decision-making under conflict, as in the probability and risk contrasts, engaged the dorsal anterior cingulate cortex whose role in conflict monitoring is well established. However, decision-making under conflict failed to activate the structures that track reward values per se. Thus, the presence of conflict in decision-making seemed to significantly alter the pattern of neural responses to simple rewards. In addition, this paradigm further clarifies the functional specialization of the cingulate cortex in processes of decision-making.

Intra-dimensional/extra-dimensional set-shifting performance in schizophrenia: impact of distractors.

BACKGROUND: We sought to determine if a representative group of young chronic patients with schizophrenia would demonstrate selective impairments in set shifting processes of the CANTAB Intra-dimensional/extra-dimensional (IDED) task. We predicted that patients would have prominent difficulties with Compound Discrimination (C_D) (stage of the task in which irrelevant stimuli are introduced) and Extra-Dimensional Shifting (EDS) (stage of the task in which a new stimulus dimension must be attended) on the basis of the results of cortical hypodopaminergic states in subhuman primates (for C_D) and effects of dorsolateral prefrontal cortical lesions on set shifting and prior results in schizophrenia (for EDS). METHODS: We administered the IDED to 36 patients and 26 healthy controls. Additionally, we administered the Wisconsin Card Sorting Test (WCST), another test of set shifting, and a Continuous Performance Test (CPT) type task of attention to patients with schizophrenia in order to investigate which cognitive components accounted for performance difficulties at different stages of the IDED task. RESULTS: Patients had selective difficulties on C_D and EDS stages of the task. In schizophrenic patients early stages of the task involving the introduction and establishment of attentional set were correlated to CPT performance, while later set shifting stages were correlated with WCST categories attained. CONCLUSION: We found evidence that patients with schizophrenia were susceptible to introduction of unreinforced irrelevant stimuli at the C_D stage, such that the previously rewarded target stimuli no longer held hegemony as a representation. This type of processing failure may reflect difficulties in stabilizing a representation and is consistent with effects of prefrontal hypodopaminergia in primates. Secondly, "survivors" of this stage experienced marked difficulties on EDS-stage, suggestive of classic prefrontal failures.

Behavioral alterations in reward system function: the role of childhood maltreatment and psychopathology.

OBJECTIVE: To examine in children the influence of maltreatment and associated psychiatric sequelae on behavioral responses to reward stimuli. METHOD: A computerized two-choice decision-making task involving probabilistic monetary gains was used to probe elemental processes of goal-directed actions. Using different risk contingencies, the authors examined decision-making, expectations of outcomes, and affective responses to rewards in 38 maltreated children and 21 demographically matched controls (8-14 years old). RESULTS: Maltreated children selected risk options faster than controls; however, whereas controls responded more quickly as the chance of winning increased, maltreated children did not vary in response speed as a function of the likelihood of winning. When choosing between high- and low-risk options, maltreated children with depressive disorders more frequently selected safe over risky choices than did controls. No group differences emerged in self-report ratings of positive or negative reactions to winning or not winning, respectively. CONCLUSIONS: This initial experimental study of responses to reward lays the groundwork for subsequent research on neurodevelopmental aspects of reward processes in relationship to maltreatment and psychopathology. Clinical applications of these data may be relevant for developing treatment plans for maltreated children, particularly those with depression.

Age-related influence of contingencies on a saccade task.

Adolescence is characterized by increased risk-taking and sensation-seeking, presumably brought about by developmental changes within reward-mediating brain circuits. A better understanding of the neural mechanisms underlying reward-seeking during adolescence can have critical implications for the development of strategies to enhance adolescent performance in potentially dangerous situations. Yet little research has investigated the influence of age on the modulation of behavior by incentives with neuroscience-based methods. A monetary reward antisaccade task (the RST) was used with 23 healthy adolescents and 30 healthy adults. Performance accuracy, latency and peak velocity of saccade responses (prosaccades and antisaccades) were analyzed. Performance accuracy across all groups was improved by incentives (obtain reward, avoid punishment) for both, prosaccades and antisaccades. However, modulation of antisaccade errors (direction errors) by incentives differed between groups: adolescents modulated saccade latency and peak velocity depending on contingencies, with incentives aligning their performance to that of adults; adults did not show a modulation by incentives. These findings suggest that incentives modulate a global measure of performance (percent direction errors) in adults and adolescents, and exert a more powerful influence on the control of incorrect motor responses in adolescents than in adults. These findings suggest that this task can be used in neuroimaging studies as a probe of the influence of incentives on cognitive control from a developmental perspective as well as in health and disease.

Cognitive control under contingencies in anxious and depressed adolescents: an antisaccade task.

BACKGROUND: Emotion-related perturbations in cognitive control characterize adult mood and anxiety disorders. Fewer data are available to confirm such deficits in youth. Studies of cognitive control and error processing can provide an ideal template to examine these perturbations. Antisaccade paradigms are particularly well suited for this endeavor because they provide exquisite behavioral measures of modulation of response errors. METHODS: A new monetary reward antisaccade task was used with 28 healthy, 11 anxious, and 12 depressed adolescents. Performance accuracy, saccade latency, and peak velocity of incorrect responses were analyzed. RESULTS: Performance accuracy across all groups was improved by incentives (obtain reward, avoid punishment). However, modulation of saccade errors by incentives differed by groups. In incentive trials relative to neutral trials, inhibitory efficiency (saccade latency) was enhanced in healthy, unaffected in depressed, and diminished in anxious adolescents. Modulation of errant actions (saccade peak velocity) was improved in the healthy group and unchanged in both the anxious and depressed groups. CONCLUSIONS: These findings provide grounds for testing hypotheses related to the impact of motivation deficits and emotional interference on directed action in adolescents with mood and anxiety disorders. Furthermore, neural mechanisms can now be examined by using this task paired with functional neuroimaging.

Amygdala and nucleus accumbens in responses to receipt and omission of gains in adults and adolescents.

Adolescents' propensity for risk-taking and reward-seeking behaviors suggests a heightened sensitivity for reward, reflected by greater feedback-related activity changes in reward circuitry (e.g., nucleus accumbens), and/or a lower sensitivity to potential harm reflected by weaker feedback-related activity changes in avoidance circuitry (e.g., amygdala) relative to adults. Responses of nucleus accumbens and amygdala to valenced outcomes (reward receipt and reward omission) were assayed using an event-related functional magnetic resonance imaging procedure paired with a monetary reward task in 14 adults and 16 adolescents. Bilateral amygdala and nucleus accumbens showed significantly greater activation when winning than when failing to win in both groups. Group comparisons revealed stronger activation of left nucleus accumbens by adolescents, and of left amygdala by adults. When examining responses to reward receipts and to reward omissions separately, the most robust group difference was within the amygdala during reward omission. The reduction of the fMRI BOLD signal in the amygdala in response to reward omission was larger for adults than for adolescents. Correlations showed a close link between negative emotion and amygdala decreased BOLD signal in adults, and between positive emotion and nucleus accumbens activation in adolescents. Overall, these findings support the notion that the signal differences between positive and negative outcomes involve the nucleus accumbens more in adolescents than in adults, and the amygdala more in adults than in adolescents. These developmental differences, if replicated, may have important implications for the development of early-onset disorders of emotion and motivation.

Reward-related processes in pediatric bipolar disorder: a pilot study.

BACKGROUND: Neuropsychological research on children with bipolar disorder (BPD) is scarce. Here, we examine reward-related behaviors in children with BPD using a Wheel of Fortune task in which subjects could win or lose money depending on their decisions. The intent of this work was to investigate performance differences between BPD and healthy children on a task that could be used in an fMRI environment to inform the neural substrates of reward processes in BPD. This study has no direct clinical implications. We hypothesized that relative to healthy children, children with BPD would select risky options more frequently, be less confident in a favorable outcome, and report stronger emotional responses to outcomes. METHODS: Forty-four children (22 BPD; 22 control) were compared on (i) decision-making with varying levels of risk, (ii) level of confidence in favorable outcomes, and (iii) responses to feedback. The task included a win-no win version and a lose-no lose version. RESULTS: Patterns of selection did not differ between groups. In the lose-no lose task, BPD patients were less confident than controls in favorable outcomes. BPD patients expressed greater dissatisfaction than controls at not winning in win-no win, and greater satisfaction than controls at not losing in lose-no lose. LIMITATIONS: Limitations of this study included that the children with BPD were mostly in a depressed state, were medicated, and had co-morbid disorders. CONCLUSIONS: This is the first experimental study to examine associations between pediatric BPD and reward-related behaviors. Although we failed to detect abnormalities in risky decision-making in children with BPD, we found significant differences between groups in both confidence ratings and response to feedback, consistent with our predictions. Our ultimate goal is to use this task in the fMRI environment to gain a better understanding of the neural correlates of reward-related processes in pediatric BPD.

Neuroimaging and mechanisms of drug abuse: interface of molecular imaging and molecular genetics.

Whereas ligand studies can inform the end-products of dysregulation of genetic expression, reporter gene imaging can provide the means to understand the genetic origin of these end-products. As with radioligand studies, in vivo direct measurement of gene expression will allow genetic processes to be monitored over time in the same subject, use of a subject as his/her own control in intervention studies (i.e., measurement before and after an intervention), and monitoring the spatial distribution of molecular events in the whole brain. Furthermore, reporter gene imaging, by advancing knowledge of the biologic mechanisms of disease states, has important clinical implications, particularly in the development and monitoring of treatments. We expect PET to play a prominent role in the elucidation of substance abuse mechanisms and contribute significantly to the development of innovative treatment strategies.