The potential antidepressant properties of probiotics have been suggested, but their influence on the emotional processes that may underlie this effect is unclear.
Depressed volunteers (
= 71) were ...recruited into a randomised double-blind, placebo-controlled study to explore the effects of a daily, 4-week intake of a multispecies probiotic or placebo on emotional processing and cognition. Mood, anxiety, positive and negative affect, sleep, salivary cortisol and serum C-reactive peptide (CRP) were assessed before and after supplementation.
Compared with placebo, probiotic intake increased accuracy at identifying faces expressing all emotions (+12%,
< 0.05, total
= 51) and vigilance to neutral faces (mean difference between groups = 12.28 ms ± 6.1,
< 0.05, total
= 51). Probiotic supplementation also reduced reward learning (-9%,
< 0.05, total
= 51), and interference word recall on the auditory verbal learning task (-18%,
< 0.05, total
= 50), but did not affect other aspects of cognitive performance. Although actigraphy revealed a significant group × night-time activity interaction, follow up analysis was not significant (
= 0.094). Supplementation did not alter salivary cortisol or circulating CRP concentrations. Probiotic intake significantly reduced (-50% from baseline,
< 0.05,
= 35) depression scores on the Patient Health Questionnaire-9, but these did not correlate with the changes in emotional processing.
The impartiality to positive and negative emotional stimuli or reward after probiotic supplementation have not been observed with conventional antidepressant therapies. Further studies are required to elucidate the significance of these changes with regard to the mood-improving action of the current probiotic.
Studies suggest that d-cycloserine (DCS) may have antidepressant potential through its interaction with the glycine site of the N-methyl-D-aspartate receptor; however, clinical evidence of DCS's ...efficacy as a treatment for depression is limited. Other evidence suggests that DCS affects emotional learning which may also be relevant for the treatment of depression and anxiety. The aim of the present investigation was to assess the effect of DCS on emotional processing in healthy volunteers and to further characterise its effects on emotional and autobiographical memory.
Forty healthy volunteers were randomly allocated to a single dose of 250 mg DCS or placebo in a double-blind design. Three hours later, participants performed an Emotional Test Battery including Facial Expression Recognition Task (FERT), Emotional Categorisation Task (ECAT), Emotional Recall Task (EREC), Facial Dot-Probe Task (FDOT) and Emotional Recognition Memory Task (EMEM) and an Autobiographical Memory Test (AMT). Also, participants performed the FERT, EREC and AMT tasks again after 24 h in order to assess longer lasting effects of a single dose of DCS.
DCS did not significantly affect the FERT, EMEM and FDOT performance but significantly increased emotional memory and classification for positive words v. negative words. Also, DCS enhanced the retrieval of more specific autobiographical memories, and this effect persisted at 24 h.
These findings support the suggestion that low-dose DCS increases specific autobiographical memory retrieval and positive emotional memory. Such effects make it an intriguing agent for further investigation in clinical depression, which is characterised by decreased autobiographical memory specificity and increased negative bias in memory recall. It also underscores the potential role of DCS as an adjunct to cognitive behavioural therapy in depression.
Adolescent major depressive disorder (MDD) is associated with disrupted processing of emotional stimuli and difficulties in cognitive reappraisal. Little is known however about how current ...pharmacotherapies act to modulate the neural mechanisms underlying these key processes. The current study therefore investigated the neural effects of fluoxetine on emotional reactivity and cognitive reappraisal in adolescent depression.
Thirty-one adolescents with MDD were randomised to acute fluoxetine (10 mg) or placebo. Seventeen healthy adolescents were also recruited but did not receive any treatment for ethical reasons. During functional magnetic resonance imaging (fMRI), participants viewed aversive images and were asked to either experience naturally the emotional state elicited ('Maintain') or to reinterpret the content of the pictures to reduce negative affect ('Reappraise'). Significant activations were identified using whole-brain analysis.
No significant group differences were seen when comparing Reappraise and Maintain conditions. However, when compared to healthy controls, depressed adolescents on placebo showed reduced visual activation to aversive pictures irrespective of the condition. The depressed adolescent group on fluoxetine showed the opposite pattern, i.e. increased visuo-cerebellar activity in response to aversive pictures, when compared to depressed adolescents on placebo.
These data suggest that depression in adolescence may be associated with reduced visual processing of aversive imagery and that fluoxetine may act to reduce avoidance of such cues. This could reflect a key mechanism whereby depressed adolescents engage with negative cues previously avoided. Future research combining fMRI with eye-tracking is nonetheless needed to further clarify these effects.
Lamotrigine is an effective mood stabiliser, largely used for the management and prevention of depression in bipolar disorder. The neuropsychological mechanisms by which lamotrigine acts to relieve ...symptoms as well as its neural effects on emotional processing remain unclear. The primary objective of this current study was to investigate the impact of an acute dose of lamotrigine on the neural response to a well-characterised fMRI task probing implicit emotional processing relevant to negative bias. 31 healthy participants were administered either a single dose of lamotrigine (300 mg, n = 14) or placebo (n = 17) in a randomized, double-blind design. Inside the 3 T MRI scanner, participants completed a covert emotional faces gender discrimination task. Brain activations showing significant group differences were identified using voxel-wise general linear model (GLM) nonparametric permutation testing, with threshold free cluster enhancement (TFCE) and a family wise error (FWE)-corrected cluster significance threshold of p < 0.05. Participants receiving lamotrigine were more accurate at identifying the gender of fearful (but not happy or angry) faces. A network of regions associated with emotional processing, including amygdala, insula, and the anterior cingulate cortex (ACC), was significantly less activated in the lamotrigine group compared to the placebo group across emotional facial expressions. A single dose of lamotrigine reduced activation in limbic areas in response to faces with both positive and negative expressions, suggesting a valence-independent effect. However, at a behavioural level lamotrigine appeared to reduce the distracting effect of fear on face discrimination. Such effects may be relevant to the mood stabilisation effects of lamotrigine.
Key points
Baclofen is a GABAB agonist prescribed as a treatment for spasticity in stroke, brain injury and multiple sclerosis patients, who are often undergoing concurrent motor rehabilitation.
...Decreasing GABAergic inhibition is a key feature of motor learning and so there is a possibility that GABA agonist drugs, such as baclofen, could impair these processes, potentially impacting rehabilitation.
Here, we examined the effect of 10 mg of baclofen, in 20 young healthy individuals, and found that the drug impaired retention of visuomotor learning with no significant effect on motor sequence learning.
Overall baclofen did not alter transcranial magnetic stimulation‐measured GABAB inhibition, although the change in GABAB inhibition correlated with aspects of visuomotor learning retention.
Further work is needed to investigate whether taking baclofen impacts motor rehabilitation in patients.
The GABAB agonist baclofen is taken daily as a treatment for spasticity by millions of stroke, brain injury and multiple sclerosis patients, many of whom are also undergoing motor rehabilitation. However, decreases in GABA are suggested to be a key feature of human motor learning, which raises questions about whether drugs increasing GABAergic activity may impair motor learning and rehabilitation. In this double‐blind, placebo‐controlled study, we investigated whether a single 10 mg dose of the GABAB agonist baclofen impaired motor sequence learning and visuomotor learning in 20 young healthy participants of both sexes. Participants trained on visuomotor and sequence learning tasks using their right hand. Transcranial magnetic stimulation (TMS) measures of corticospinal excitability, GABAA (short‐interval intracortical inhibition, 2.5 ms) and GABAB (long‐interval intracortical inhibition, 150 ms) receptor activation were recorded from left M1. Behaviourally, baclofen caused a significant reduction of visuomotor aftereffect (F1,137.8 = 6.133, P = 0.014) and retention (F1,130.7 = 4.138, P = 0.044), with no significant changes to sequence learning. There were no overall changes to TMS measured GABAergic inhibition with this low dose of baclofen. This result confirms the causal importance of GABAB inhibition in mediating visuomotor learning and suggests that chronic baclofen use could negatively impact aspects of motor rehabilitation.
Key points
Baclofen is a GABAB agonist prescribed as a treatment for spasticity in stroke, brain injury and multiple sclerosis patients, who are often undergoing concurrent motor rehabilitation.
Decreasing GABAergic inhibition is a key feature of motor learning and so there is a possibility that GABA agonist drugs, such as baclofen, could impair these processes, potentially impacting rehabilitation.
Here, we examined the effect of 10 mg of baclofen, in 20 young healthy individuals, and found that the drug impaired retention of visuomotor learning with no significant effect on motor sequence learning.
Overall baclofen did not alter transcranial magnetic stimulation‐measured GABAB inhibition, although the change in GABAB inhibition correlated with aspects of visuomotor learning retention.
Further work is needed to investigate whether taking baclofen impacts motor rehabilitation in patients.
Trait anxiety is associated with an excessive processing of danger-related stimuli, predisposing individuals to quickly detect threatening cues. Early, automatic mechanisms are believed to be ...responsible for the production of these cognitive biases; however, limitations in the paradigms most commonly used to achieve visual suppression or attentional unawareness have left open the possibility of strategic mechanisms influencing these early stages of information processing. Establishing whether symptoms of anxiety are associated with truly automatic biases in processing is an essential step in determining their etiology and in developing targeted cognitive interventions. We addressed this question using continuous flash suppression (CFS), a novel and robust method of visual suppression capable of rendering a stimulus invisible from awareness for extended durations. We specifically investigated the degree to which trait anxiety influenced the suppression of threatening, positive, and neutral faces. Forty-nine individuals, with no reported history of psychological problems and varying levels of anxiety, were recruited. Higher trait anxiety scores were associated with an increased speed to detect fearful compared with happy faces. These results indicate that the bias toward threatening information associated with symptoms of anxiety operates, at least partly, at an early stage of information processing. This suggests that cognitive interventions for anxiety may benefit from directly targeting such early and potentially preconscious processes.
Objective
The aim of the present study was to evaluate the effectiveness of psychoeducation for bipolar I inpatients following remission of a manic episode in a Chinese population.
Method
The study ...recruited currently medicated bipolar I patients, aged 18–60 years, who were in remission from a manic episode, as determined using the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM‐5). Patients were randomized (1:1) to either eight sessions of group‐based psychoeducation (active treatment group) or regular free discussions (control group). The primary outcomes were the rates of any type of recurrence and rehospitalization following treatment. The secondary outcomes were changes in mood symptoms, medication adherence, global functioning, as well as treatment response (as measured using the Clinical Global Impression scale). Subjects were assessed at baseline and then at 2 weeks, and 1, 2, 3, 5, 7, 9, and 12 months following treatment.
Results
At 1 year, patients receiving the psychoeducation treatment demonstrated significantly less recurrence. Those in the treatment group also showed a significant reduction in mania recurrence but not depressive recurrence, and psychoeducation increased time to remission. Notably, lower rates of rehospitalization were found in the active treatment group. Those receiving the psychoeducation treatment also revealed higher change from baseline on measures of depression (17‐item Hamilton Rating Scale for Depression), mania (Young Mania Rating Scale), global functioning (Clinical Global Impression–severity scale and World Health Organization Disability Assessment Schedule) (P<.05). However, there were no significant group differences for the medication adherence scores.
Conclusion
This preliminary evidence suggests that short, group‐based psychoeducation benefits currently medicated inpatients following the remission of mania in bipolar I disorder. This intervention warrants further investigation, especially in other Chinese populations. If future studies confirm its benefits, group‐based psychoeducation could be incorporated into routine psychiatric inpatient care for bipolar patients in China.
Baclofen is a GABA
agonist prescribed as a treatment for spasticity in stroke, brain injury and multiple sclerosis patients, who are often undergoing concurrent motor rehabilitation. Decreasing ...GABAergic inhibition is a key feature of motor learning and so there is a possibility that GABA agonist drugs, such as baclofen, could impair these processes, potentially impacting rehabilitation. Here, we examined the effect of 10 mg of baclofen, in 20 young healthy individuals, and found that the drug impaired retention of visuomotor learning with no significant effect on motor sequence learning. Overall baclofen did not alter transcranial magnetic stimulation-measured GABA
inhibition, although the change in GABA
inhibition correlated with aspects of visuomotor learning retention. Further work is needed to investigate whether taking baclofen impacts motor rehabilitation in patients.
The GABA
agonist baclofen is taken daily as a treatment for spasticity by millions of stroke, brain injury and multiple sclerosis patients, many of whom are also undergoing motor rehabilitation. However, decreases in GABA are suggested to be a key feature of human motor learning, which raises questions about whether drugs increasing GABAergic activity may impair motor learning and rehabilitation. In this double-blind, placebo-controlled study, we investigated whether a single 10 mg dose of the GABA
agonist baclofen impaired motor sequence learning and visuomotor learning in 20 young healthy participants of both sexes. Participants trained on visuomotor and sequence learning tasks using their right hand. Transcranial magnetic stimulation (TMS) measures of corticospinal excitability, GABA
(short-interval intracortical inhibition
2.5 ms) and GABA
(long-interval intracortical inhibition
150 ms) receptor activation were recorded from left M1. Behaviourally, baclofen caused a significant reduction of visuomotor aftereffect (F
= 6.133, P = 0.014) and retention (F
= 4.138, P = 0.044), with no significant changes to sequence learning. There were no overall changes to TMS measured GABAergic inhibition with this low dose of baclofen. This result confirms the causal importance of GABA
inhibition in mediating visuomotor learning and suggests that chronic baclofen use could negatively impact aspects of motor rehabilitation.
Fluoxetine is commonly prescribed in adolescent depression, but the neural mechanisms underlying its action remain poorly understood. Here, we used resting-state functional magnetic resonance imaging ...to investigate the effects of a single dose of fluoxetine vs. placebo in adolescents with major depressive disorder. In contrast with previous studies in adults that have demonstrated an acute effect of antidepressants on activity within the default mode network, a single dose of fluoxetine did not alter activity in this network in adolescent depression. There were unexpected group activity differences in the motor network, which should be clarified in future research.
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