Modulation of cognitive performance and mood by aromas of peppermint and ylang-ylang

This study provides further evidence for the impact of the aromas of plant essential oils on aspects of cognition and mood in healthy participants. One hundred and forty-four volunteers were randomly assigned to conditions of ylang-ylang aroma, peppermint aroma, or no aroma control. Cognitive performance was assessed using the Cognitive Drug Research computerized assessment battery, with mood scales completed before and after cognitive testing. The analysis of the data revealed significant differences between conditions on a number of the factors underpinning the tests that constitute the battery. Peppermint was found to enhance memory whereas ylang-ylang impaired it, and lengthened processing speed. In terms of subjective mood peppermint increased alertness and ylang-ylang decreased it, but significantly increased calmness. These results provide support for the contention that the aromas of essential oils can produce significant and idiosyncratic effects on both subjective and objective assessments of aspects of human behavior. They are discussed with reference to possible pharmacological and psychological modes of influence.     

Aromas of rosemary and lavender essential oils differentially affect cognition and mood in healthy adults

This study was designed to assess the olfactory impact of the essential oils of lavender (Lavandula angustifolia) and rosemary (Rosmarlnus officinalis) on cognitive performance and mood in healthy volunteers. One hundred and forty-four participants were randomly assigned to one of three independent groups, and subsequently performed the Cognitive Drug Research (CDR) computerized cognitive assessment battery in a cubicle containing either one of the two odors or no odor (control). Visual analogue mood questionnaires were completed prior to exposure to the odor, and subsequently after completion of the test battery. The participants were deceived as to the genuine aim of the study until the completion of testing to prevent expectancy effects from possibly influencing the data. The outcome variables from the nine tasks that constitute the CDR core battery feed into six factors that represent different aspects of cognitive functioning. Analysis of performance revealed that lavender produced a significant decrement in performance of working memory, and impaired reaction times for both memory and attention based tasks compared to controls. In contrast, rosemary produced a significant enhancement of performance for overall quality of memory and secondary memory factors, but also produced an impairment of speed of memory compared to controls. With regard to mood, comparisons of the change in ratings from baseline to post-test revealed that following the completion of the cognitive assessment battery, both the control and lavender groups were significantly less alert than the rosemary condition; however, the control group was significantly less content than both rosemary and lavender conditions. These findings indicate that the olfactory properties of these essential oils can produce objective effects on cognitive performance, as well as subjective effects on mood.     

Subjective cognitive complaints relate to mild impairment of cognition in multiple sclerosis

Cognitive impairment is common in multiple sclerosis (MS), but cannot be reliably predicted by physical impairment. The negative impact of cognitive impairment makes early detection important, but subjective cognitive complaints may be attributed to depression. We examined the relationship between subjectively reported and objectively measured cognitive impairment in MS, adjusting for mood. A neuropsychological battery, the Multiple Sclerosis Functional Composite (MSFC), the Mental Health Inventory (MHI), the Modified Fatigue Impact Scale (MFIS), the Perceived Deficits Questionnaire (PDQ) were administered to 136 patients. Demographically-adjusted cognitive scores were calculated. Subjective impairment was defined as PDQ score >2 standard deviations above that for healthy persons. We modeled the relationship of cognitive scores (independent variables) to being subjectively impaired (dependent variable) using logistic regression. Immediate Memory (IM) and Processing Speed Index (PSI) scores were non-linearly related to subjective impairment Patients were less likely to report subjective impairment if their PSI was normal (OR =0.11; 0.02-0.73) or markedly impaired (OR =0.17; 0.03-0.91), compared to mildly reduced PSI. In young patients decreases in IM were associated with increased subjective impairment (OR = 1.25; 1.07-1.47). Subjectively reported impairment reflects subtle declines in PSI and IM independent of mood, fatigue, and physical impairment Cognitive complaints should not be discounted due to depression.     

Psychological effects of aromatherapy on chronic hemodialysis patients

Effects of aromatherapy (odorless condition, lavender, and hiba oil) on mood and anxiety were investigated in 14 female patients who were being treated with chronic hemodialysis. A control period consisting of natural hospital smells was established before each test session, and then aromatic test conditions were systematically evaluated for odorless conditions as well as aromatic conditions containing lavender and hiba oil aromas. The effects of aromatherapy were measured using the Hamilton rating scale for depression (HAMD) and the Hamilton rating scale for anxiety (HAMA). Hiba oil aroma significantly decreased the mean scores of HAMD and HAMA, and lavender aroma significantly decreased the mean scores of HAMA. The mean scores of HAMD and HAMA in an odorless condition were not significantly different from those of the control conditions. These results indicate that in chronic hemodialysis patients hiba oil is an effective, non-invasive means for the treatment of depression and anxiety, and that lavender alleviates anxiety.     

Frequency of insomnia report in patients with obstructive sleep apnoea hypopnea syndrome (OSAHS)

BACKGROUND AND PURPOSE: Insomnia and Obstructive Sleep Apnoea Hypopnea Syndrome (OSAHS) are the two most common sleep disorders, and both have significant associated health costs. Despite this, relatively little is known about the prevalence or impact of insomnia in those with OSAHS, although a recent study suggested there may be substantial comorbidity between these disorders [Chest 120 (2001) 1923-9]. The primary aim of this study was to further explore the prevalence of insomnia in OSAHS. A secondary aim was to assess the effect of factors that may impact on both conditions, including mood and sleep-beliefs. PATIENTS AND METHODS: Consecutive patients referred to an accredited Sleep Investigations Unit [n = 105] completed a brief standardized battery of validated questionnaires assessing sleep-related variables and mood. RESULTS: Results showed a high rate of prevalence of clinical insomnia in this OSAHS population, and a strong positive correlation between OSAHS and insomnia symptom severity. Further, OSAHS patients with comorbid insomnia had increased levels of depression, anxiety and stress compared to patients with OSAHS-only, and both patient groups reported similar and significant levels of dysfunctional beliefs about sleep. Findings in relation to habitual sleep, assessed using subjective (diary) and objective criteria (polysomnogram), were mixed but generally showed greater sleep disturbance among those with OSAHS-insomnia compared to those with OSAHS-only. CONCLUSIONS: Overall these findings suggest that comorbidity of insomnia in OSAHS patients may lead to increased OSAHS severity and that patients with both conditions may experience more symptoms relating to depression, anxiety and stress. These findings underscore the need for insomnia assessment and management services, even in clinics that primarily service patients with OSAHS.     

Metacognition in HIV-1 seropositive asymptomatic individuals: self-ratings versus objective neuropsychological performance. Multicenter AIDS Cohort Study (MACS)

This study examined the relationship between actual and self-reported neuropsychological deficits, depression, and HIV-1 serostatus. The subjects, who consisted of 479 individuals, 256 who were HIV seronegative (SN) and 233 who were HIV-1 seropositive though still asymptomatic (ASP), were administered a standardized neuropsychological screening battery consisting of measures of attention, motor speed, psychomotor speed, verbal memory, verbal fluency, and depression. To assess subjects' subjective sense of their cognitive status, the Cognitive Failures Questionnaire (CFQ), a 25-item self-report questionnaire, was also administered. The results of MANOVA failed to reveal group differences between the SN and ASP groups on the measures of neuropsychological function. Similarly, the ASP and SN groups did not differ on the number or severity of reported cognitive failures. However, a positive correlation was found between CFQ scores and level of depression. These results do not support the hypothesis that ASP individuals are aware of cognitive decline prior to detection using standard neuropsychologic screening instruments. The data do suggest that the presence of depressed mood, independent of serostatus or actual neuropsychological impairment, is associated with increased cognitive complaints.     

Approximate entropy of symptoms of mood: an effective technique to quantify regularity of mood

Objectives:  Several psychiatric conditions are associated with lability of affect. In this study, we investigated regularity of mood using APEN (Approximate Entropy) on daily subjective ratings using a Visual Analog Scale with 11 items pertaining to mood.
Methods:  APEN was applied to the data in a double-blind placebo controlled investigation on the effects of fluoxetine (n=19), pemoline (n=18) and placebo (n=20) in normal controls. These subjects rated their subjective feelings daily at the end of each day. We analysed 56 data point time series (each value was obtained on each day) after the three experimental conditions.
Results:  While the mean or the SD of all the 56 points was not significantly different among the three conditions, APEN was highly and significantly lower for pemoline compared with fluoxetine and placebo. There was no significant correlation between average APEN and mean or SD (standard deviation). The one symptom that explained most of this difference among the groups after drug administration was the feeling of 'happiness'.
Conclusions:  This result indicates that there was a more consistent subjective sense of happiness during the 8-week period of pemoline administration compared with the other two drugs. Though this study was not designed to address the efficacy of mood stabilizing drugs, such daily subjective ratings may be useful in future studies that evaluate the stability of mood. APEN has been used in several different fields of research with small data sets and this study extends its possible use to evaluate changes in mood in certain populations such as patients with bipolar disorders.     

Randomized double-blind parallel-group study comparing cognitive effects of a low-dose lamotrigine with valproate and placebo in healthy volunteers

PURPOSE: This study aimed at investigating the cognitive and mood effects of lamotrigine (LTG) versus valproate (VPA) and placebo (PBO). METHODS: By studying the effects in healthy volunteers, it is possible to separate the genuine effects of LTG from the cognitive improvements, caused by better seizure control. The study used a pretest-posttest comparison of 50 mg LTG, 900 mg VPA, or PBO in a double-blind single-dummy parallel-group design with 30 healthy volunteers. Study duration was 12 days (with a last control on day 13). Outcome measures included cognitive tests (FePsy neuropsychological test battery), mood scales (ASL; mood-rating scale), and a scale for subjective complaints (ABNAS Neurotoxicity scale). Total sleep time was controlled with actigraphic recordings. The results were analyzed by comparing the change over time (pretest with posttest) for the three treatments with Student's t tests. RESULTS: COGNITIVE TESTS: significant differences between the treatments were found for measurements of cognitive activation (i.e., three of the four simple reaction-time measurements showed statistically significant differences in change between PBO and LTG in favor of LTG (p=0.03; 0.03; 0.04); two of four tests showed statistically significant differences in change between LTG and VPA, both in favor of LTG (p=0.03; 0.05). SUBJECTIVE COMPLAINTS: the ABNAS-neurotoxicity scale reveals a significant reduction of drug-related cognitive complaints for the subjects taking LTG, relative to VPA (p=0.02). MOOD RATING: significant changes were found on the scale assessing "tiredness," showing increased tiredness/sedation for VPA relative to PBO (p=0.02) and on the "timid scale" for LTG reporting "being more at ease" compared with both PBO and VPA (p=0.02; 0.02). The general direction of change for the mood scales was toward "activation" for LTG (five of six scales improved), whereas for VPA, the reverse effect was found (four of six scales showed a change in the direction of "tiredness/sedation"). CONCLUSIONS: Short-term treatment in normal volunteers with a low dose of LTG resulted in improved cognitive activation on simple reaction-time measurements, a more positive subjective report about the impact of drug treatment relative to VPA, and mood changes concurring with the activating effect demonstrated by the cognitive tests.     

Depressed mood and subjective health symptoms as predictors of mortality in patients with congestive heart failure: a two-years follow-up study

OBJECTIVE: The present study was undertaken in order to evaluate the relationship between depressed mood (depression, emotional distress) and disease-specific subjective health symptoms upon mortality risk among patients with congestive heart failure (CHF). METHODS AND RESULTS: Proportional hazard models were used to evaluate the effects of selected biomedical, subjective health and psychological variables on mortality among 119 clinically stable patients (71.4% men; mean age 65.7 years +/- 9.6) with symptomatic heart failure, recruited from an outpatient cardiology practice. Twenty deaths were registered during the twenty-four-month period of data collection, all from cardiac causes. Results indicated that depressed mood was a significant predictor of mortality with a hazard ratio of 1.9, p .002. In contrast, subjective health was not a significant predictor of mortality in a Cox regression model that included depressed mood. The hazard ratio for a 1-point increase in Zung Depression Scale score was equal to 1.08 based on the multivariate model. CONCLUSIONS: Results indicate that depressed mood is significantly related to increased mortality risk among heart failure patients. This finding is of concern to clinicians and should have implications for treatment of patients with congestive heart failure.     

Effects of Vigabatrin on Cognitive Function and Mood When Used as Add-on Therapy in Patients with Intractable Epilepsy

Cognitive function and mood of patients with epilepsy who received 2 g/day vigabatrin (GVG) in addition to their usual antiepileptic drugs (AEDs) was assessed on two occasions: before start of treatment (baseline) and 4 weeks after start of treatment. A battery of selected psychological tasks measuring attention, mental speed, motor speed, central cognitive processing, and perceptuomotor performance was used, along with standardized, objective mood assessments. A comparison group (n = 15) of patients receiving stable medication was also tested to evaluate practice effects of the psychometric tests. Administration of 2 g/day GVG significantly decreased response time on a test of central cognitive processing ability (arithmetic). No adverse effect was noted on any other test of cognitive function or mood.     

Cognitive variables and depressed mood in adults with intellectual disability

Background Cognitive theory forms the foundation for cognitive therapy. There has been little research on cognitive theories and cognitive variables associated with depression in individuals with intellectual disability (ID). The current study examined cognitive variables of automatic thoughts, cognitive triad, hopelessness, attributions and self-esteem associated with two cognitive theories of depression: Beck's Cognitive Triad theory and the Hopelessness theory of depression. Methods Seventy-three adults with ID screened for adequate receptive vocabulary were interviewed as part of a larger study. They reported on cognitive constructs relating to depressed mood. In addition, comparisons were made between 12 adults with ID and diagnosed major depression and a matched group of 12 adults with ID and no psychiatric diagnoses in order to determine if these groups differed on the cognitive constructs associated with the two cognitive theories of depression. Results The cognitive variables examined were all significantly correlated with depressed mood in the direction predicted by their respective cognitive theory. Internal consistencies were good or excellent for most instruments, with the exception of those measuring hopelessness and attributions. In addition, significant differences were obtained between groups of individuals with and without co-morbid major depression on all variables except for hopelessness. Conclusions The results indicate that adults with ID screened for adequate receptive vocabulary are capable of reporting on subjective feelings of depressed mood and associated cognition constructs. The instruments used may be suitable for this population as they generally possessed sound internal consistencies. The results support the further examination of cognitive theories of depression among individuals with ID in order to assess the appropriateness of cognitive therapies for this population. Discrepant findings regarding hopelessness are discussed.     

Increased positive versus negative affective perception and memory in healthy volunteers following selective serotonin and norepinephrine reuptake inhibition

OBJECTIVE: Antidepressants that inhibit the reuptake of serotonin (SSRIs) or norepinephrine (SNRIs) are effective in the treatment of disorders such as depression and anxiety. Cognitive psychological theories emphasize the importance of correcting negative biases of information processing in the nonpharmacological treatment of these disorders, but it is not known whether antidepressant drugs can directly modulate the neural processing of affective information. The present study therefore assessed the actions of repeated antidepressant administration on perception and memory for positive and negative emotional information in healthy volunteers. METHOD: Forty-two male and female volunteers were randomly assigned to 7 days of double-blind intervention with the SSRI citalopram (20 mg/day), the SNRI reboxetine (8 mg/day), or placebo. On the final day, facial expression recognition, emotion-potentiated startle response, and memory for affect-laden words were assessed. Questionnaires monitoring mood, hostility, and anxiety were given before and after treatment. RESULTS: In the facial expression recognition task, citalopram and reboxetine reduced the identification of the negative facial expressions of anger and fear. Citalopram also abolished the increased startle response found in the context of negative affective images. Both antidepressants increased the relative recall of positive (versus negative) emotional material. These changes in emotional processing occurred in the absence of significant differences in ratings of mood and anxiety. However, reboxetine decreased subjective ratings of hostility and elevated energy. CONCLUSIONS: Short-term administration of two different antidepressant types had similar effects on emotion-related tasks in healthy volunteers, reducing the processing of negative relative to positive emotional material. Such effects of antidepressants may ameliorate the negative biases in information processing that characterize mood and anxiety disorders. They also suggest a mechanism of action potentially compatible with cognitive theories of anxiety and depression.     

Evaluation of cognitive assessment and cognitive intervention for people with multiple sclerosis

OBJECTIVES: Cognitive problems in multiple sclerosis are common but any possible benefits of treatment remain uncertain. The aim of the study was to evaluate the benefits of providing a psychology service, including cognitive assessment and intervention, to patients with multiple sclerosis. METHOD: The study was a single blind randomised controlled trial. A total of 240 patients with clinically definite, laboratory supported, or clinically probable multiple sclerosis were recruited from an multiple sclerosis management clinic and assessed on a brief screening battery. They were randomised into three groups. The control group received no further intervention. The assessment group received a detailed cognitive assessment, the result of which was fed back to staff involved in the patients' care. The treatment group received the same detailed cognitive assessment and a treatment programme designed to help reduce the impact of their cognitive problems. Patients were followed up 4 and 8 months later on the general health questionnaire (GHQ-28), extended activities of daily living scale, SF-36, everyday memory questionnaire, dysexecutive syndrome questionnaire, and memory aids questionnaire. RESULTS: The three groups were compared on the outcome measures at 4 and 8 months after recruitment. There were few significant differences between the groups and those that occurred favoured the control group. Overall, the results showed no effect of the interventions on mood, quality of life, subjective cognitive impairment or independence. CONCLUSIONS: The study failed to detect any significant effects of cognitive assessment or cognitive intervention in this cohort of people with multiple sclerosis.     

Patients with epilepsy: Cognitively compromised before the start of antiepileptic drug treatment?

Purpose:   To compare the cognitive profile of newly diagnosed untreated epilepsy patients with healthy volunteers using a comprehensive neuropsychological test battery.
Methods:   A total of 155 untreated patients with newly diagnosed epilepsy, and no known brain pathology, were assessed before the start of treatment with antiepileptic medication. Their scores across the neuropsychological measures were compared with 87 healthy volunteers from the general population equated for age and sex.
Results:   After adjusting for age, sex, and education, patients with epilepsy performed significantly worse than healthy volunteers on 6 of 14 cognitive measures, particularly in the domains of memory and psychomotor speed. Cognitive performance was not related to the number of seizures, type of epilepsy, or mood. When an impairment index was calculated, 53.5% patients had a least one abnormal score [>2 standard deviations (SD) below the control mean] on the test battery compared with 20.7% of healthy volunteers.
Discussion:   Newly diagnosed untreated patients with epilepsy are cognitively compromised before the start of antiepileptic drug medication. The domains most affected are memory and psychomotor speed. More than one-half of the patients had at least one abnormal test score across the test battery. There were no differences in epilepsy-related or mood variables between those who demonstrated dysfunction and those that did not.     

Accuracy of self-reported neuropsychological functioning in individuals with epileptic or psychogenic nonepileptic seizures

The aim of this study was to determine the degree to which subjective ratings of neurocognitive ability accurately reflect objectively measured neuropsychological functioning in patients diagnosed with epileptic (ES, n = 45) or psychogenic nonepileptic (PNES; n = 37) seizures. Patients received a battery of neuropsychological tests, measures of current mood state, and the Quality of Life In Epilepsy-89 questionnaire. Results indicated that subjective ratings of neuropsychological functioning were only partially accurate within each group. Patients with ES accurately rated their memory function, but overestimated language and attention abilities. Patients with PNES accurately rated attention, but underestimated memory and overestimated language. In both groups, poorer self-reported neurocognitive functioning was strongly related to poorer mood state; however, mood state did not predict objectively measured neurocognitive abilities. Given the inaccuracies that exist in patient self-report, results highlight the importance of a comprehensive neuropsychological assessment when evaluating the neurocognitive status of individuals with seizures.     

An integrative approach to determine the best behavioral and biological markers of methylphenidate

AIMS: To distinguish the most sensitive markers of methylphenidate (MPH) effects on behavior and underlying biology using an integrated cognitive and brain function test battery. METHODS: A randomized placebo-controlled trial with 32 healthy adult males. Subjects were tested on MPH doses across 18 sessions with subjective mood, objective behavioral and biological endpoints. From a computerized battery of tests, behavioral measures were cognitive performance scores, while biological measures of brain function included electroencephalographs (EEG) and event-related potentials (ERPs) with complementary measures of autonomic arousal. Using mixed modeling analyses; we determined which measures were most affected by MPH dose and correlation analyses determined the associations among them. RESULTS: MPH dose had the most pronounced effect on cognitive performance (sustained attention/vigilance), baseline autonomic arousal (heart rate, blood pressure) and baseline brain activity (EEG theta power). The faster reaction time, reduced errors, increased autonomic arousal and reductions in theta showed strong to moderate inter-correlations. MPH least affected subjective mood measures and early sensory ERP components. DISCUSSION: These findings suggest that MPH increases cortical and autonomic arousal, facilitating vigilance. The combination of behavioral and biological measures may provide an objective set of markers of MPH response. INTEGRATIVE SIGNIFICANCE: This approach has provided additional insight into the mechanism of the stimulant medication, MPH, which would not be achieved by using such measures in isolation.     

Age-related cognitive decline in patients with mood disorders

BACKGROUND: The relationship between depression and dementia is complex and appreciation of its true nature is evolving. Depression is an early symptom of dementia. Recent research suggests that mood disorders, in general, may be risk factors for the development of dementia. METHOD: This was a cross-sectional study of the effect of aging on cognition in patients with mood disorders compared to normal controls. Patients and controls were tested with a comprehensive neurocognitive test battery, CNS Vital Signs. The question at issue was the rate of aging-related cognitive decline the same or different in mood disorder patients compared to normal controls. SUBJECTS: 455 patients with mood disorders, 336 with major depression and 119 with bipolar affective disorder, age 18-86, and 1003 normal controls, age 35-90. Normal controls were age 18 or older in the CNS Vital Signs normative database. The normal subjects were healthy, on no centrally-active medication, and free of psychiatric and neurological disorders. RESULTS: Cognitive performance in the two groups run in parallel from age 18 to 45; they begin to diverge during the next decade; after age 65, mood disorder patients, as a group, decline more sharply than normal controls. The differential rate of decline was seen in the domains of memory, attention, processing speed and executive function. CONCLUSIONS: There seems to be an acceleration in age-related cognitive decline in patients with depression in particular, and mood disorders in general, compared to age-matched normal controls. It is likely, then, that as people age, the ones who develop depression, or who fail to recover from early episodes of depression, include a substantial number of patients at risk for developing dementia. This is consistent with the fact that late-life depression may be an early manifestation of dementia. The data are also consistent with the idea that mood disorders are a risk factor, albeit a weak one, for the development of dementia. From a slightly different perspective, one might imagine that some pathophysiological event is shared by the mood disorders and dementing conditions.     

Can Ambient Scent Enhance the Nightlife Experience?

Ever since smoking was prohibited in restaurants, bars, and clubs, undesirable smells that were previously masked by cigarette smoke became noticeable. This opens up opportunities to improve the dance club environment by introducing pleasant ambient scents that mask the unwanted odors and to allow competing clubs to differentiate themselves. A field study was conducted at three dance clubs using a 3?×?3 Latin square design with pre- and post-measurements of no-scent control conditions. The three scents tested were orange, seawater, and peppermint. These scents were shown to enhance dancing activity and to improve the evaluation of the evening, the evaluation of the music, and the mood of the visitors over no added scent. However, no significant differences were found between the three scents.     

Effects of total sleep deprivation on urinary cortisol, self-rated arousal, and mood in depressed patients

The possibility that the clinical response to total sleep deprivation (TSD) is mediated by dimensions of arousal was investigated in a group of 16 depressed patients. Self-reports of activation, stress, and mood were assessed 3 days before, during, and 2 days after TSD. Urinary cortisol excretion and responses to the dexamethasone suppression test (DST) were also measured. TSD increased cortisol excretion in depressed patients and advanced the time of the maximal excretion of cortisol. No such changes have been reported for normal subjects. Neither the increased excretion nor the time shift was related to the mood response to TSD. The DST results were also unrelated to this response. Indications that the mood response to TSD may be mediated by dimensions of arousal are the significant relationships between this response and the responses of subjective stress and activation to TSD. The TSD-induced cortisol increase was not related to the subjective arousal response to TSD. The increased cortisol excretion itself could be predicted by the averaged baseline levels of subjective stress: the lower the stress levels before TSD, the larger the cortisol response to TSD.     

Deep brain stimulation of the subthalamic nucleus enhances emotional processing in Parkinson disease

BACKGROUND: High-frequency electrical stimulation of the subthalamic nucleus is a new and highly effective therapy for complications of long-term levodopa therapy and motor symptoms in advanced Parkinson disease (PD). Clinical observations indicate additional influence on emotional behavior. METHODS: Electrical stimulation of deep brain nuclei with pulse rates above 100 Hz provokes a reversible, lesioning-like effect. Here, the effect of deep brain stimulation of the subthalamic nucleus on emotional, cognitive, and motor performance in patients with PD (n = 12) was examined. The results were compared with the effects of a suprathreshold dose of levodopa intended to transiently restore striatal dopamine deficiency. Patients were tested during medication off/stimulation off (STIM OFF), medication off/stimulation on (STIM ON), and during the best motor state after taking levodopa without deep brain stimulation (MED). RESULTS: More positive self-reported mood and an enhanced mood induction effect as well as improvement in emotional memory during STIM ON were observed, while during STIM OFF, patients revealed reduced emotional performance. Comparable effects were revealed by STIM ON and MED. Cognitive performance was not affected by the different conditions and treatments. CONCLUSIONS: Deep brain stimulation of the subthalamic nucleus selectively enhanced affective processing and subjective well-being and seemed to be antidepressive. Levodopa and deep brain stimulation had similar effects on emotion. This finding may provide new clues about the neurobiologic bases of emotion and mood disorders, and it illustrates the important role of the basal ganglia and the dopaminergic system in emotional processing in addition to the well-known motor and cognitive functions.