To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Cognitive impairments are an important feature of both remitted and depressed major depressive disorder (MDD) and bipolar disorder (BD). In particular, deficits in executive functioning may hamper everyday functioning. Identifying the neural substrates of impaired executive functioning would improve our understanding of the pathophysiology underlying these disorders, and may eventually aid in discriminating between MDD and BD, which is often difficult during depression and remission. To date, mostly medicated MDD and BD subjects have been investigated, which may have influenced results. Therefore, we investigated executive functioning in medication-free depressed and remitted MDD and BD subjects.
We used the Tower of London (ToL) visuospatial planning task to assess behavioural performance and blood oxygen-level dependent responses in 35 healthy controls, 21 remitted MDD, 23 remitted BD, 19 depressed MDD and nine depressed BD subjects.
Visuospatial planning per se was associated with increased frontostriatal activity in depressed BD compared to depressed MDD. In addition, post-hoc analyses indicated that visuospatial planning load was associated with increased parietal activity in depressed compared to remitted subjects, and BD compared to MDD subjects. Task performance did not significantly differ between groups.
More severely affected, medication-free mood disorder patients require greater parietal activity to perform in visuospatial planning, which may be compensatory to maintain relatively normal performance. State-dependent frontostriatal hyperactivity during planning may be a specific BD characteristic, providing clues for further characterization of differential pathophysiology in MDD v. BD. This could potentially provide a biomarker to aid in the differentiation of these disorders.
Impaired emotion regulation may underlie exaggerated emotional reactivity in patients with obsessive compulsive disorder (OCD), yet instructed emotion regulation has never been studied in the disorder.
This study aimed to assess the neural correlates of emotion processing and regulation in 43 medication-free OCD patients and 38 matched healthy controls, and additionally test if these can be modulated by stimulatory (patients) and inhibitory (controls) repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (dlPFC). Participants performed an emotion regulation task during functional magnetic resonance imaging before and after a single session of randomly assigned real or sham rTMS. Effect of group and rTMS were assessed on self-reported distress ratings and brain activity in frontal-limbic regions of interest.
Patients had higher distress ratings than controls during emotion provocation, but similar rates of distress reduction after voluntary emotion regulation. OCD patients compared with controls showed altered amygdala responsiveness during symptom provocation and diminished left dlPFC activity and frontal-amygdala connectivity during emotion regulation. Real v. sham dlPFC stimulation differentially modulated frontal-amygdala connectivity during emotion regulation in OCD patients.
We propose that the increased emotional reactivity in OCD may be due to a deficit in emotion regulation caused by a failure of cognitive control exerted by the dorsal frontal cortex. Modulatory rTMS over the left dlPFC may influence automatic emotion regulation capabilities by influencing frontal-limbic connectivity.
Impulsive decision making is a hallmark of frequently occurring addiction disorders including alcohol dependence (AD). Therefore, ameliorating impulsive decision making is a promising target for the treatment of AD. Previous studies have shown that modafinil enhances cognitive control functions in various psychiatric disorders. However, the effects of modafinil on delay discounting and its underlying neural correlates have not been investigated as yet. The aim of the current study was to investigate the effects of modafinil on neural correlates of impulsive decision making in abstinent AD patients and healthy control (HC) subjects.
A randomized, double-blind, placebo-controlled, within-subjects cross-over study using functional magnetic resonance imaging (fMRI) was conducted in 14 AD patients and 16 HC subjects. All subjects participated in two fMRI sessions in which they either received a single dose of placebo or 200 mg of modafinil 2 h before the session. During fMRI, subjects completed a delay-discounting task to measure impulsive decision making.
Modafinil improved impulsive decision making in AD pateints, which was accompanied by enhanced recruitment of frontoparietal regions and reduced activation of the ventromedial prefrontal cortex. Moreover, modafinil-induced enhancement of functional connectivity between the superior frontal gyrus and ventral striatum was specifically associated with improvement in impulsive decision making.
These findings indicate that modafinil can improve impulsive decision making in AD patients through an enhanced coupling of prefrontal control regions and brain regions coding the subjective value of rewards. Therefore, the current study supports the implementation of modafinil in future clinical trials for AD.
The inability to inhibit certain behaviors is a key feature of impulsivity, which is often present in people with a substance use disorder. However, the findings on impulsivity in people with alcohol dependence (AD) are inconsistent, possibly because of the frequent co-occurrence of depression/anxiety (D/A) and its influence on impulsivity. In the current study, we aimed to distinguish response inhibition impairments in AD from possible response inhibition effects associated with D/A.
AD patients (n = 31) with high D/A co-morbidity were compared to patients with D/A only (n = 18) and healthy controls (HCs; n = 16) using the Stop Signal Task (SST) during functional magnetic resonance imaging (fMRI). Correlation analyses were performed between activated brain areas, behavioral data and addiction and D/A characteristics.
The three groups did not differ on response inhibition performance. However, AD severity, but not D/A severity, was positively associated with decreased response inhibition. During the SST, AD patients showed hyperactivity in the putamen and thalamus compared with D/A patients and HCs. Thalamus activation was negatively associated with AD duration. In addition, AD patients showed hypoactivity in the supplementary motor area (SMA) compared with HCs. SMA activity within HCs was negatively correlated with depressive symptom severity.
In general, AD patients were not more impulsive than D/A patients or HCs but they did reveal inhibition impairments with increasing AD severity. A shift from cortical to subcortical engagement in AD patients during response inhibition may represent an alternative strategy, which decreased with longer drinking history, suggesting the presence of an AD-specific endophenotype.
Anxiety disorders are associated with substantial functional limitations but the course of functioning following symptom remission remains largely unknown.
Using data from the Netherlands Study of Depression and Anxiety (NESDA), we examined the 2-year trajectories of functioning in participants with chronic (n = 586) or remitting anxiety disorders (n = 385) and in healthy controls (n = 585). In participants with remitting anxiety disorders, we identified predictors of functioning from among sociodemographic, clinical and vulnerability variables. Data were analysed using linear mixed models (LMMs). Functioning was assessed with the World Health Organization Disability Assessment Schedule II (WHO DAS II).
At baseline, participants with remitting anxiety disorders functioned significantly better than those with chronic anxiety disorders, but significantly worse than controls. In both anxiety disorder groups, most impairment was reported in social functioning, occupational functioning and cognition. During the follow-up, functioning improved in both groups, probably due to treatments received. Participants who achieved symptom remission experienced moderate improvements in social functioning and cognition but not in occupational functioning. Of those who remitted, 45.8% reported functioning scores similar to healthy controls whereas 28.5% still functioned at the level of those with chronic anxiety disorders. Worse functioning was predicted by severe anxiety disorders, use of psychological treatment, co-morbid depressive disorders and maladaptive personality traits.
In anxiety disorders, symptom remission is accompanied by improvements in functioning but significant functional impairments may persist because of co-morbid disorders, lower functioning prior to the onset of the anxiety disorder or residual subthreshold anxiety symptoms.
Childhood emotional maltreatment (CEM) has been associated with disturbances in emotional and behavioral functioning, and with changes in regional brain morphology. However, whether CEM has any effect on the intrinsic organization of the brain is not known. In this study, we investigated the effects of CEM on resting-state functional connectivity (RSFC) using seeds in the limbic network, the default-mode network (DMN) and the salience network, and the left dorsomedial prefrontal cortex (dmPFC).
Using 3-T magnetic resonance imaging (MRI), resting-state functional MRI (RS-fMRI) scans were obtained. We defined seeds in the bilateral amygdala, the dorsal anterior cingulate cortex (dACC), the posterior cingulate cortex (PCC) and the left dmPFC, and used these to examine whether individuals reporting CEM (n=44) differed from individuals reporting no CEM (n=44) in RSFC with other brain regions. The two groups were matched for age, gender, handedness and the presence of psychopathology.
CEM was associated with decreased RSFC between the right amygdala and the bilateral precuneus and a cluster extending from the left insula to the hippocampus and putamen. In addition, CEM was associated with decreased RSFC between the dACC and the precuneus and also frontal regions of the brain.
We found that CEM has a profound effect on RSFC in the limbic network and the salience network. Regions that show aberrant connectivity are related to episodic memory encoding, retrieval and self-processing operations.
A family history (FH) of alcohol dependence (AD) not only increases the risk for AD, but is also associated with an increased risk for mood and anxiety disorders. However, it is unknown how a FH of AD affects neural substrates in patients with mood and anxiety disorders. In this study we examined the effects of an alcoholic FH on cognitive and emotional functions in these patients using functional magnetic resonance imaging (fMRI).
In a sample of non-alcoholic patients with depressive and/or anxiety disorders from the Netherlands Study of Depression and Anxiety (NESDA) neuroimaging study, patients with a first-degree FH of AD (FH + ; n = 31) were compared with patients without a FH (FH–; n = 77) on performance and brain activation during visuospatial planning and emotional word encoding. Results were compared with those of healthy controls (HCs) without a FH of AD (n = 31).
FH+ patients performed slower during planning with increasing task load, coupled with stronger blood oxygen level-dependent responses in dorsal prefrontal areas compared with FH− patients and HCs. FH was not associated with performance differences during word encoding, but right insula activation during positive word encoding was present in FH+ patients, comparable with HCs, but absent in FH− patients.
This study demonstrates subtle impairments during planning in FH+ compared with FH− patients and HCs, whereas activation during mood-incongruent stimuli in FH+ patients was similar to HCs but not FH− patients, suggesting that the presence of a FH of AD is a useful marker for the neurophysiological profile in mood/anxiety disorders and possible predictor for treatment success.
Functional neuroimaging studies have shown increased Stroop interference coupled with altered anterior cingulate cortex (ACC) and insula activation in post-traumatic stress disorder (PTSD). These brain areas are associated with error detection and emotional arousal. There is some evidence that treatment can normalize these activation patterns.
At baseline, we compared classic and emotional Stroop performance and blood oxygenation level-dependent responses (functional magnetic resonance imaging) of 29 child abuse-related complex PTSD patients with 22 non-trauma-exposed healthy controls. In 16 of these patients, we studied treatment effects of psycho-educational and cognitive behavioural stabilizing group treatment (experimental treatment; EXP) added to treatment as usual (TAU) versus TAU only, and correlations with clinical improvement.
At baseline, complex PTSD patients showed a trend for increased left anterior insula and dorsal ACC activation in the classic Stroop task. Only EXP patients showed decreased dorsal ACC and left anterior insula activation after treatment. In the emotional Stroop contrasts, clinical improvement was associated with decreased dorsal ACC activation and decreased left anterior insula activation.
We found further evidence that successful treatment in child abuse-related complex PTSD is associated with functional changes in the ACC and insula, which may be due to improved selective attention and lower emotional arousal, indicating greater cognitive control over PTSD symptoms.
Depression has been associated with limbic hyperactivation and frontal hypoactivation in response to negative facial stimuli. Anxiety disorders have also been associated with increased activation of emotional structures such as the amygdala and insula. This study examined to what extent activation of brain regions involved in perception of emotional faces is specific to depression and anxiety disorders in a large community-based sample of out-patients.
An event-related functional magnetic resonance imaging (fMRI) paradigm was used including angry, fearful, sad, happy and neutral facial expressions. One hundred and eighty-two out-patients (59 depressed, 57 anxiety and 66 co-morbid depression-anxiety) and 56 healthy controls selected from the Netherlands Study of Depression and Anxiety (NESDA) were included in the present study. Whole-brain analyses were conducted. The temporal profile of amygdala activation was also investigated.
Facial expressions activated the amygdala and fusiform gyrus in depressed patients with or without anxiety and in healthy controls, relative to scrambled faces, but this was less evident in patients with anxiety disorders. The response shape of the amygdala did not differ between groups. Depressed patients showed dorsolateral prefrontal cortex (PFC) hyperactivation in response to happy faces compared to healthy controls.
We suggest that stronger frontal activation to happy faces in depressed patients may reflect increased demands on effortful emotion regulation processes triggered by mood-incongruent stimuli. The lack of strong differences in neural activation to negative emotional faces, relative to healthy controls, may be characteristic of the mild-to-moderate severity of illness in this sample and may be indicative of a certain cognitive-emotional processing reserve.
Direct comparisons of brain function between obsessive compulsive disorder (OCD) and other anxiety or OCD spectrum disorders are rare. This study aimed to investigate the specificity of altered frontal-striatal and limbic activations during planning in OCD, a prototypical anxiety disorder (panic disorder) and a putative OCD spectrum disorder (hypochondriasis).
The Tower of London task, a ‘frontal-striatal’ task, was used during functional magnetic resonance imaging measurements in 50 unmedicated patients, diagnosed with OCD (n=22), panic disorder (n=14) or hypochondriasis (n=14), and in 22 healthy subjects. Blood oxygen level-dependent (BOLD) signal changes were calculated for contrasts of interest (planning versus baseline and task load effects). Moreover, correlations between BOLD responses and both task performance and state anxiety were analysed.
Overall, patients showed a decreased recruitment of the precuneus, caudate nucleus, globus pallidus and thalamus, compared with healthy controls. There were no statistically significant differences in brain activation between the three patient groups. State anxiety was negatively correlated with dorsal frontal-striatal activation. Task performance was positively correlated with dorsal frontal-striatal recruitment and negatively correlated with limbic and ventral frontal-striatal recruitment. Multiple regression models showed that adequate task performance was best explained by independent contributions from dorsolateral prefrontal cortex (positive correlation) and amygdala (negative correlation), even after controlling for state anxiety.
Patients with OCD, panic disorder and hypochondriasis share similar alterations in frontal-striatal brain regions during a planning task, presumably partly related to increased limbic activation.
Several lines of research suggest a disturbance of reversal learning (reward and punishment processing, and affective switching) in patients with major depressive disorder (MDD). Obsessive–compulsive disorder (OCD) is also characterized by abnormal reversal learning, and is often co-morbid with MDD. However, neurobiological distinctions between the disorders are unclear. Functional neuroimaging (activation) studies comparing MDD and OCD directly are lacking.
Twenty non-medicated OCD-free patients with MDD, 20 non-medicated MDD-free patients with OCD, and 27 healthy controls performed a self-paced reversal learning task in an event-related design during functional magnetic resonance imaging (fMRI).
Compared with healthy controls, both MDD and OCD patients displayed prolonged mean reaction times (RTs) but normal accuracy. In MDD subjects, mean RTs were correlated with disease severity. Imaging results showed MDD-specific hyperactivity in the anterior insula during punishment processing and in the putamen during reward processing. Moreover, blood oxygen level-dependent (BOLD) responses in the dorsolateral prefrontal cortex (DLPFC) and the anterior PFC during affective switching showed a linear decrease across controls, MDD and OCD. Finally, the OCD group showed blunted responsiveness of the orbitofrontal (OFC)–striatal loop during reward, and in the OFC and anterior insula during affective switching.
This study shows frontal–striatal and (para)limbic functional abnormalities during reversal learning in MDD, in the context of generic psychomotor slowing. These data converge with currently influential models on the neuropathophysiology of MDD. Moreover, this study reports differential neural patterns in frontal–striatal and paralimbic structures on this task between MDD and OCD, confirming previous findings regarding the neural correlates of deficient reversal learning in OCD.
Email your librarian or administrator to recommend adding this to your organisation's collection.