Psychomotor functioning in chronic fatigue syndrome and major depressive disorder: a comparative study

People with Long Covid and ME/CFS Exhibit Similarly Impaired Dexterity and Bimanual Coordination: A Case-Case-Control Study

PURPOSE

Dexterity and bimanual coordination had not previously been compared between people with long COVID and people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Therefore, this study determined dexterity and bimanual coordination in people with long COVID (∼16 month illness duration; n=21) and ME/CFS (∼16 year illness duration; n=20), versus age-matched healthy controls (n=20).

METHODS

Dexterity, and bimanual coordination was determined using the Purdue pegboard test.

RESULTS

The main findings of the present investigation were that people with ME/CFS and people with long COVID were generally comparable for Purdue pegboard tests (p>0.556 and d<0.36 for pairwise comparisons). It is worth noting however, that both these patient groups performed poorer in the Perdue pegboard test than healthy controls (p<0.169 and d>0.40 for pairwise comparisons).

CONCLUSIONS

These data suggest that both people with long COVID and people with ME/CFS have similarly impaired dexterity, and bimanual coordination. Therefore, there is an urgent need for interventions to target dexterity and bimanual coordination in people with ME/CFS, and given the current pandemic, people with long COVID.

Reward-based reinforcement learning is altered among individuals with a history of major depressive disorder and psychomotor retardation symptoms

Reward-based reinforcement learning impairments are common in major depressive disorder, but it is unclear which aspects of reward-based reinforcement learning are disrupted in remitted major depression (rMDD). Given that the neurobiological substrates that implement reward-based RL are also strongly implicated in psychomotor retardation (PmR), the present study sought to test whether reward-based reinforcement learning is altered in rMDD individuals with a history of PmR. Three groups of individuals (1) rMDD with past PmR (PmR+, N = 34), (2) rMDD without past PmR (PmR-, N = 44), and (3) healthy controls (N = 90) completed a reward-based reinforcement learning task. Computational modeling was applied to test for group differences in model-derived parameters - specifically, learning rates and reward sensitivity. Compared to controls, rMDD PmR + exhibited lower learning rates, but not reduced reward sensitivity. By contrast, rMDD PmR- did not significantly differ from controls on either of the model-derived parameters. Follow-up analyses indicated that the results were not due to current psychopathology symptoms. Results indicate that a history of PmR predicts altered reward-based reinforcement learning in rMDD. Abnormal reward-related reinforcement learning may reflect a scar of past depressive episodes that contained psychomotor symptoms, or a trait-like deficit that preceded these episodes.

Systematic review and meta-analysis of cognitive impairment in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is commonly associated with cognitive complaints. To bring out the neuropsychological symptomatology inherent to ME/CFS, we conducted a systematic review according to PRISMA and MOOSE guidelines of the literature through the analysis of 764 studies published between 1988 and 2019 by using PubMed Central website and Clarivate analytics platform. We performed a meta-analysis to delineate an idea of the neuropsychological profile inherent in ME/CFS. The clinical picture typically affects visuo-spatial immediate memory (g = - 0.55, p = 0.007), reading speed (g = - 0.82, p = 0.0001) and graphics gesture (g = - 0.59, p = 0.0001). Analysis also revealed difficulties in several processes inherent in episodic verbal memory (storage, retrieval, recognition) and visual memory (recovery) and a low efficiency in attentional abilities. Executive functions seemed to be little or not affected and instrumental functions appeared constantly preserved. With regard to the complexity and heterogeneity of the cognitive phenotype, it turns out that determining a sound clinical picture of ME/CFS cognitive profile must go through a neuropsychological examination allowing a complete evaluation integrating the notion of agreement between the choice and the number of tests and the complexity intrinsic to the pathology.

Hand gesture performance is impaired in major depressive disorder: A matter of working memory performance?

OBJECTIVE

Individuals with depression exhibit numerous interpersonal deficits. As effective use of gestures is critical for social communication, it is possible that depressed individuals' interpersonal deficits may be due to deficits in gesture performance. The present study thus compared gesture performance of depressed patients and controls and examined whether these deficits relate to cognitive and other domains of dysfunction.

METHODS

Gesture performance was evaluated in 30 depressed patients and 30 controls using the Test of Upper Limb Apraxia (TULIA). Clinical rating scales were assessed to determine if gesture deficits were associated with motor, cognitive or functional outcomes.

RESULTS

Compared to controls, depressed patients exhibited impaired gesture performance with 2/3 of the patients demonstrating gesture deficits. Within depressed patients, gesture performance was highly correlated with working memory abilities. In contrast, no association between gesture performance and gestural knowledge, psychomotor retardation, depression severity, or frontal dysfunction was observed in patients.

LIMITATIONS

This is a cross-sectional study and a larger size would have allowed for confident detection of more subtle, but potentially relevant effects.

CONCLUSION

Gesture performance is impaired in depressed patients, and appears to be related to poor working memory abilities, suggesting a disruption in the retrieval of gestural cues indicative of a distinct clinical phenomenon that might be related to social functioning.

Diagnosing solvent-induced chronic toxic encephalopathy: the effect of underperformance in neuropsychological testing

Objective: The diagnoses of solvent-induced chronic toxic encephalopathy (CSE) can be supported by neuropsychological tests. However, since results not only reflect cognitive functioning but also the patient's effort to perform well, this study examines to what extent underperformance impacts neuropsychological outcomes in individuals referred for suspected CSE. Methods: A retrospective study of 48 suspected CSE patients having completed ten neuropsychological tests assessing different domains of cognition. Underperformance was identified using the Amsterdam Short-Term Memory Test and the Rey 15-item Memory Test (FIT). Multiple linear regression was applied to examine the effect of insufficient effort on test performance. Results: A total of 54.1% of the patients were identified as having underperformed on one or both performance validity tests. Analyses showed a significant effect of underperformance on most tests barring letter-number sequencing. Conclusions: Most of the neuropsychological tests evaluated showed significant effects of underperformance. Performance on letter-number sequencing was not affected. In case of underperformance, the results of the neuropsychological assessment should be disregarded when weighing the final multi-disciplinary diagnosis, with the exception of letter-number sequencing. Key points A total of 54.1% of patients with suspected CSE referred for neuropsychological assessment was identified as having underperformed on one or both PVTs. Underperformance has a significant effect on most neuropsychological tests with the exception of letter-number sequencing assessing attention and working memory. In case of underperformance, the results of the neuropsychological assessment should be disregarded when weighing the final multi-disciplinary diagnosis, with the exception of letter-number sequencing.

Association study of SLC6A2 gene Thr99Ile variant (rs1805065) with athletic status in the Brazilian population

Genetic variants in monoamine neurotransmitter genes have been recurrently associated with panic disorder, addiction and mood disorders. Recent evidence also indicates that norepinephrine neurotransmission can influence a series of psychophysical and psychobiological parameters related to athletic performance, and the presence of variants in the SLC6A2 (solute carrier family 6 member 2) gene, which encodes the norepinephrine transporter, can be detrimental to an adequate noradrenergic signaling. Accordingly, the objective of the present study was to explore the SLC6A2 Thr99Ile variant (rs1805065) in a cohort composed of highly-trained individuals and non-trained individuals. A total of 1556 Brazilians: 926 non-athletes and 630 athletes (322 endurance athletes and 308 power athletes) were compared in this case-control association study. The Thr99Ile variant showed only two genotypes (C/C or C/T), and a low minor allele frequency of ≈1%. However, none of the power athletes had the mutant T-allele (i.e., the C/T genotype), which may be related to decreased norepinephrine transporter activity. The genotype distribution and allele frequency observed in power athletes were significantly different when compared to non-athletes or endurance athletes. Therefore, the presence of the T-allele may decrease the chance of belonging to the group of athletes involved in explosive physical tasks. These results still need to be replicated in independent cohorts. However, it appears reasonable to assume that there is an association between the SLC6A2 gene variant and power athletic status.

Reduced cardiac vagal modulation impacts on cognitive performance in chronic fatigue syndrome

Background

Cognitive difficulties and autonomic dysfunction have been reported separately in patients with chronic fatigue syndrome (CFS). A role for heart rate variability (HRV) in cognitive flexibility has been demonstrated in healthy individuals, but this relationship has not as yet been examined in CFS. The objective of this study was to examine the relationship between HRV and cognitive performance in patients with CFS.

Methods

Participants were 30 patients with CFS and 40 healthy controls; the groups were matched for age, sex, education, body mass index, and hours of moderate exercise/week. Questionnaires were used to obtain relevant medical and demographic information, and assess current symptoms and functional impairment. Electrocardiograms, perceived fatigue/effort and performance data were recorded during cognitive tasks. Between–group differences in autonomic reactivity and associations with cognitive performance were analysed.

Results

Patients with CFS showed no deficits in performance accuracy, but were significantly slower than healthy controls. CFS was further characterized by low and unresponsive HRV; greater heart rate (HR) reactivity and prolonged HR-recovery after cognitive challenge. Fatigue levels, perceived effort and distress did not affect cognitive performance. HRV was consistently associated with performance indices and significantly predicted variance in cognitive outcomes.

Conclusions

These findings reveal for the first time an association between reduced cardiac vagal tone and cognitive impairment in CFS and confirm previous reports of diminished vagal activity.

More severe impairment of manual dexterity in bipolar disorder compared to unipolar major depression

BACKGROUND

Mood disorders are associated with various neurocognitive deficits. However, few studies have reported the impairment of motor dexterity in unipolar depression and bipolar disorder. In the present study, manual dexterity was compared between unipolar major depression, bipolar disorder, and healthy controls.

METHODS

Manual dexterity was assessed by the Purdue pegboard test in 98 patients with unipolar major depression, 48 euthymic or depressed patients with bipolar disorder, and 158 healthy controls, matched for age and gender.

RESULTS

Compared to healthy controls, sum of the scores of right, left, and both hands subtests (R+L+B) was significantly lower in both patients with unipolar depression and bipolar disorder (P=0.0034 and P<0.0001, respectively). Furthermore, R+L+B was significantly lower in bipolar disorder compared to unipolar depression (P=0.0016). Lithium dose and chlorpromazine equivalent dose of antipsychotics were significantly negatively correlated with some of the subtest scores. On the other hand, depression severity did not significantly correlate with any of the subtest scores. Difference in R+L+B between unipolar depression and bipolar disorder remained statistically significant even after controlling for gender, age, lithium dose, and chlorpromazine equivalent dose (P=0.0028). Limitations Bipolar patients during manic episode were not included in the study.

CONCLUSIONS

Gross movement dexterity was impaired in both patients with unipolar depression and bipolar disorder. The severity of impairment was significantly greater in patients with bipolar disorder. The functional difference between unipolar and bipolar patients may suggest different pathological conditions between the two depressive disorders.

Motor activity in depressed children

BACKGROUND

Motor retardation is a cardinal feature in adult depression. Limited information exists about motor activity in depressed children. The present study evaluated motor activity in depressed children compared to controls and investigated whether motor activity can be linked with the severity of symptoms in depressed children.

METHOD

Motor activity during both day- and night time was recorded by actigraphy in twenty-two depressed children and their controls. A K-SADS-PL interview of the child and his/her mother was used to diagnose depression. The depressed children filled in the Child Depression Inventory (CDI) as a self-report of the severity of depression. Parents and teachers of both depressed children and controls filled in the Child Behavior Checklist (CBCL) and the Teacher Report Form (TRF).

RESULTS

Motor activity was reduced during the daytime in depressed children compared to controls (p<0.001). Depressed children spent more time in total immobility during the night time than their peers (p<0.05). In depressed children motor activity was linked with the severity of self- (r=-0.45, p<0.05) and teacher-reported (r=-0.52, p<0.05) symptoms. Depressed children with suicidal ideation (n=10) differed significantly in motor activity compared to depressed children without suicidal ideation (n=12) and controls (n=22).

LIMITATIONS

Sample size was only moderate.

CONCLUSIONS

Reduced motor activity is an important feature of childhood depression. Objectively measured motor activity can distinguish depressed children from their peers. Motor retardation can be linked with the severity of depression, especially suicidal ideation and possibly subtype depressed children into groups with different etiology, treatment needs and course of illness.

Psychomotor function and response inhibition in chronic fatigue syndrome

Most research points to cognitive slowing in chronic fatigue syndrome (CFS), although there have been negative reports. The present study is one of few that examines fine motor processing and the inhibition of automatic responses in a well-characterised CFS population. A total of 35 female CFS patients without current major depression and 25 female controls performed two computerised figure-copying tasks. The cognitive and fine motor processing of visual-spatial information was measured by recording reaction time (RT) and movement time (MT), respectively. The inhibition of automatic responses was assessed by introducing 'conflicting patterns' (i.e., patterns that were difficult to draw from the preferred left to right). A multivariate general linear model was adopted for the statistical analysis of the movement recordings. As a result, CFS was significantly associated with longer RT and MT in the pooled and in the task-specific analyses. However, there was no interaction between disease status and conflicting character of the patterns. In conclusion, these performance data on the figure-copying tasks provide confirmatory evidence for psychomotor slowing in CFS, but not for a disturbed inhibition of automatic responses. Computerised figure-copying tasks may be promising tools for use in neurobiological research and clinical trials in CFS.

Cognitive deficits in patients with chronic fatigue syndrome compared to those with major depressive disorder and healthy controls

OBJECT

Chronic fatigue syndrome (CFS) patients report usually cognitive complaints. They also have frequently comorbid depression that can be considered a possible explanation for their cognitive dysfunction. We evaluated the cognitive performance of patients with CFS in comparison with a control group of healthy volunteers and a group of patients with MDD.

PATIENTS AND METHODS

Twenty-five patients with CFS, 25 patients with major depressive disorder (MDD), and 25 healthy control subjects were given standardized tests of attention, working memory, and verbal and visual episodic memory, and were also tested for effects related to lack of effort/simulation, suggestibility, and fatigue.

RESULTS

Patients with CFS had slower phasic alertness, and also had impaired working, visual and verbal episodic memory compared to controls. They were, however, no more sensitive than the other groups to suggestibility or to fatigue induced during the cognitive session. Cognitive impairments in MDD patients were strongly associated with depression and subjective fatigue; in patients with CFS, there was a weaker correlation between cognition and depression (and no correlation with fatigue).

CONCLUSIONS

This study confirms the presence of an objective impairment in attention and memory in patients with CFS but with good mobilization of effort and without exaggerated suggestibility.

Perspectives on fatigue from the study of chronic fatigue syndrome and related conditions

Fatigue is a symptom whose causes are protean and whose phenotype includes physical, mood, and behavioral components. Chronic fatigue syndrome (CFS) is an illness that has strong biological underpinnings and no definite etiology. Diagnostic criteria established by the Centers for Disease Control and Prevention have helped classify CFS as an overlap of mood, behavioral, and biological components. These include the presence of fatigue for more than 6 months associated with a diminution of functional activity and somatic symptoms, and pain not attributable to a specific diagnosis or disease. Four of the following criteria need to be present: sore throat, impaired memory or cognition, unrefreshing sleep, postexertional fatigue, tender glands, aching stiff muscles, joint pain, and headaches. Many researchers have observed that CFS shares features in common with other somatic syndromes, including irritable bowel syndrome, fibromyalgia, and temporomandibular joint dysfunction. Correlations between inflammation and infection, augmented sensory processing, abnormalities of neurotransmitters, nerve growth factors, low levels of serotonin and norepinephrine, abnormalities of homeostasis of the stress system, and autonomic dysfunction may be hallmarks of CFS. The relative contributions of each of these abnormalities to the profound fatigue associated with CFS need to be explored further to better evaluate and treat the syndrome.

A functional polymorphism in the disrupted-in schizophrenia 1 gene is associated with chronic fatigue syndrome

AIMS

Disrupted-in schizophrenia 1 (DISC1), identified in a pedigree with a familial psychosis with the chromosome translocation (1:11), is a putative susceptibility gene for psychoses such as schizophrenia and major depressive disorder (MDD). Patients with chronic fatigue syndrome (CFS) report having continuous severe fatigue and many overlapping symptoms with MDD; however, the mechanism and effective treatment of CFS are still unclear. We focused on the overlapping symptoms between CFS and MDD and performed an association study of the functional single-nucleotide polymorphism (SNP) in the DISC1 gene with CFS.

MAIN METHODS

Venous blood was drawn from CFS patients and controls and genomic DNA was extracted from the whole blood according to standard procedures. Ser704Cys DISC1 SNP was genotyped using the TaqMan 5'-exonuclease allelic discrimination assay.

KEY FINDINGS

We found that the Cys704 allele of Ser704Cys SNP was associated with an increased risk of CFS development compared with the Ser704 allele.

SIGNIFICANCE

DISC1 Ser704Cys might be a functional variant that affects one of the mechanisms implicated in the biology of CFS. Some patients with CFS showed a phenotype similar to that of patients with MDD, but further studies are needed to clarify the biological mechanism, because this study is of a rather preliminary nature. Despite the variety of patients with CFS, DISC1 Ser704Cys has an association with CFS, which may also suggest that DISC1 plays a central role in the induction of various psychiatric diseases.