Sara Dallaspezia

Actimetric evidence that CLOCK 3111 T/C SNP influences sleep and activity patterns in patients affected by bipolar depression.

Depressive insomnia and diurnal fluctuations of mood and activity are core clinical features of mood disorders. Here we studied the effect of CLOCK 3111 T/C SNP (rs1801260) on the actimetric recorded diurnal activity and nocturnal sleep of 39 bipolar depressed inpatients. Compared to T/T homozygotes, carriers of the C allele had a similar degree of severity of depression, but showed higher activity levels in the evening, a delayed sleep onset (mean 79 min later), and a reduced amount of sleep during the night (mean 75 min less). Ongoing lithium treatment significantly interacted with rs1801260 by enhancing activity levels in the evening and reducing the differences among genotype groups. Individual characteristics of the molecular clock can influence sleep symptoms in mood disorders.

Disruption of White Matter Integrity in Bipolar Depression as a Possible Structural Marker of Illness

BACKGROUND Diffusion tensor imaging allows the study of integrity of white matter (WM) tracts. Literature suggests that WM integrity could be altered in bipolar disorder. Heterogeneity of brain imaging methods, the studied samples, and drug treatments make localization, nature, and severity of the WM abnormalities unclear. METHODS We applied tract-based spatial statistics of diffusion tensor imaging measures to compare fractional anisotropy (FA), mean, and radial diffusivity of the WM skeleton in a group of 40 consecutively admitted inpatients affected by a major depressive episode without psychotic features with a diagnosis of bipolar disorder type I and 21 unrelated healthy volunteers from the general population. RESULTS Compared with control subjects, patients showed lower FA in the genu of the corpus callosum and in anterior and right superior-posterior corona radiata and higher values of radial diffusivity in WM tracts of splenium, genu and body of corpus callosum, right mid-dorsal part of the cingulum bundle, left anterior and bilateral superior and posterior corona radiata, bilateral superior longitudinal fasciculus, and right posterior thalamic radiation. Patients had no brain areas with higher FA or lower diffusivity values than control subjects. CONCLUSIONS Reduced FA with increased mean and radial diffusivity suggests significant demyelination and/or dysmyelination without axonal loss. Comparing our findings with other observations in homogeneous samples of euthymic and manic patients, it can be hypothesized that changes in measures of WM integrity might parallel illness phases of bipolar illness.

Functional and structural brain correlates of theory of mind and empathy deficits in schizophrenia

BACKGROUND Patients affected by schizophrenia show deficits in social cognition, with abnormal performance on tasks targeting theory of mind (ToM) and empathy (Emp). Brain imaging studies suggested that ToM and Emp depend on the activation of brain networks mainly localized at the superior temporal lobe and temporo-parietal junction. METHODS Participants included 24 schizophrenia patients and 20 control subjects. We used brain blood oxygen level dependent fMRI to study the neural responses to tasks targeting ToM and Emp. We then studied voxel-based morphometry of grey matter in areas where diagnosis influenced functional activation to both tasks. Outcomes were analyzed in the context of the general linear model, with global grey matter volume as nuisance covariate for structural MRI. RESULTS Patients showed worse performance on both tasks. We found significant effects of diagnosis on neural responses to the tasks in a wide cluster in right posterior superior temporal lobe (encompassing BA 22-42), in smaller clusters in left temporo-parietal junction and temporal pole (BA 38 and 39), and in a white matter region adjacent to medial prefrontal cortex (BA 10). A pattern of double dissociation of the effects of diagnosis and task on neural responses emerged. Among these areas, grey matter volume was found to be reduced in right superior temporal lobe regions of patients. CONCLUSIONS Functional and structural abnormalities were observed in areas affected by the schizophrenic process early in the illness course, and known to be crucial for social cognition, suggesting a biological basis for social cognition deficits in schizophrenia.

Tract-specific white matter structural disruption in patients with bipolar disorder

OBJECTIVES A growing body of evidence suggests that, independent of localized brain lesions, mood disorders can be associated with dysfunction of brain networks involved in the modulation of emotional and cognitive behavior. We used diffusion tensor (DT) tractography to quantify the presence and extent of structural injury to the connections between the amygdala and other brain regions, which included the subgenual, the supragenual and posterior cingulate, the parahippocampal, the orbitofrontal and dorsolateral prefrontal cortices, as well as the insula. METHODS Using a 3.0 Tesla scanner, conventional and DT magnetic resonance imaging sequences of the brain were acquired from 15 adult patients with major depressive disorder (MDD), 15 with bipolar disorder (BD), and 21 age-matched healthy controls. Using FSL software, diffusivity changes of the white matter (WM) fiber bundles belonging to the emotional network were measured. RESULTS Compared to controls and MDD patients, BD patients had significantly decreased average fractional anisotropy, increased average mean diffusivity, and increased average axial and radial diffusivity values in the majority of the WM fiber bundles connecting structures of the anterior limbic network (p-values ranging from 0.002 to 0.040). Medication load did not influence the results with the exception of lithium, which was associated with normal diffusivity values in tracts connecting the amygdala with the subgenual cingulate cortex. CONCLUSIONS We detected specific WM abnormalities, suggestive of disrupted integrity of fiber bundles in the brains of patients with BD. These abnormalities might contribute to understanding both mood dysregulation and cognitive disturbances in BD, and might provide an objective marker to monitor treatment efficacy in this condition.

A length polymorphism in the circadian clock gene Per3 influences age at onset of bipolar disorder

Age at onset of bipolar disorder might represent the penetrance of the system for specific genetic liability involved in the genesis of the illness. Genetic factors influencing age at onset have been shown to play a role in shaping core characteristics of the illness, such as severity and pattern of recurrence. Genetic variants of genes regulating the circadian clock could contribute to define endophenotypes of bipolar disorder, and have been associated with clinical features of the disease. The coding region of Per3 gene contains a variable-number tandem-repeat (VNTR) polymorphism which has been associated with diurnal preference, sleep structure and sleep homeostasis in healthy subjects. In a homogeneous sample of 99 patients affected by bipolar disorder type I we observed that Per3 VNTR influenced age at onset of illness: earlier age at onset in homozygote carriers of Per35 variant, later in homozygotes for Per34, and intermediate in heterozygotes. Allele frequencies were not significantly different from those reported in healthy subjects. Results need to be confirmed in larger samples, but warrant interest for the variants of molecular clock genes as possible endophenotypes of bipolar disorder.

Phase advance is an actimetric correlate of antidepressant response to sleep deprivation and light therapy in bipolar depression.

The combination of total sleep deprivation (TSD) and light therapy (LT) in bipolar depression causes rapid antidepressant effects, and its mechanism of action has been hypothesized to involve the enhancement of all of the monoaminergic systems targeted by antidepressant drugs (serotonin, dopamine, norepinephrine). It is still unknown if the clinical effects are paralleled by changes in biological rhythms. In a before/after design of a study of biological correlates of response, 39 inpatients affected by Type I Bipolar Disorder whose current depressive episode was without psychotic features were treated for one week with repeated TSD combined with morning LT. Wrist actigraphy was recorded throughout the study. Two‐thirds of the patients responded to treatment (50% reduction in Hamilton Depression score). Responders showed an increase in daytime activity, phase‐advance of the activity‐rest rhythm of 57 min compared to the pre‐treatment baseline, and reduced nighttime sleep. Non‐responders did not show significant changes in the parameters of their activity‐rest rhythm. Phase advance of the activity‐rest rhythm is an actimetric correlate of the antidepressant response to TSD and LT in bipolar depression. Results are consistent with the known effects of sleep‐wake manipulations and neurotransmitter function on the suprachiasmatic nucleus.

Chronobiological therapy for mood disorders

Alteration of the sleep–wake cycle and of the sleep structure are core symptoms of a major depressive episode, and occur both in course of bipolar disorder and of major depressive disorder. Many other circadian rhythms, such as the daily profiles of body temperature, cortisol, thyrotropin, prolactin, growth hormone, melatonin and excretion of various metabolites in the urine, are disrupted in depressed patients, both unipolar and bipolar individuals. These disrupted rhythms seem to return to normality with patient recovery. Research on circadian rhythms and sleep have led to the definition of nonpharmacological therapies of mood disorder that can be used in everyday practice. These strategies, named chronotherapeutics, are based on controlled exposures to environmental stimuli that act on biological rhythms, and demonstrate good efficacy in the treatment of illness episodes. They include manipulations of the sleep–wake rhythm (such as partial and total sleep deprivation, and sleep phase advance) and of the exposure to the light–dark cycle (light therapy and dark therapy). In recent years, an increasing literature about the safety and efficacy of chronobiological treatments in everyday psychiatric settings has supported the inclusion of these techniques among the first-line antidepressant strategies for patients affected by mood disorders.

Clock genes beyond the clock: CLOCK genotype biases neural correlates of moral valence decision in depressed patients.

Gene polymorphisms in the mammalian biological clock system influence individual rhythms. A single nucleotide polymorphism (SNP) in the 3′ flanking region of CLOCK (3111 T/C; rs1801260) influenced diurnal preference in healthy humans and caused sleep phase delay and insomnia in patients affected by bipolar disorder. Genes of the biological clock are expressed in many brain structures other than in the ‘master clock’ suprachiasmatic nuclei. These areas, such as cingulate cortex, are involved in the control of many human behaviors. Clock genes could then bias ‘nonclock’ functions such as information processing and decision making. Thirty inpatients affected by a major depressive episode underwent blood oxygen–level dependent (BOLD) functional magnetic resonance imaging (fMRI). The cognitive activation paradigm was based on a go/no‐go task. Morally connoted words were presented. Genotyping of CLOCK was performed for each patients. We measured activity levels through actimetry during the day before the fMRI study. CLOCK 3111 T/C SNP was associated with activity levels in the second part of the day, neuropsychological performance and BOLD fMRI correlates (interaction of genotype and moral valence of the stimuli). Our results support the hypothesis that individual clock genotype may influence several variables linked with human behaviors in normal and psychopathological conditions.

Rapid treatment response of suicidal symptoms to lithium, sleep deprivation, and light therapy (chronotherapeutics) in drug-resistant bipolar depression.

BACKGROUND One third of patients with bipolar disorder attempt suicide. Depression in bipolar disorder is associated with drug resistance. The efficacy of antidepressants on suicidality has been questioned. Total sleep deprivation and light therapy prompt a rapid and stable antidepressant response in bipolar disorder. METHOD We studied 143 consecutively admitted inpatients (December 2006-August 2012) with a major depressive episode in the course of bipolar disorder (DSM-IV criteria). Among the 141 study completers, 23% had a positive history of attempted suicide and 83% had a positive history of drug resistance. During 1 week, patients were administered 3 consecutive total sleep deprivation cycles (each composed of a period of 36 hours awake followed by recovery sleep) combined with bright light therapy in the morning for 2 weeks. At admission, patients who had been taking lithium continued it, and those who had not been taking lithium started it. Severity of depression was rated according to the Hamilton Depression Rating Scale (HDRS) (primary outcome measure) and Beck Depression Inventory (BDI). RESULTS Two patients switched polarity. Among the 141 who completed the treatment, 70% achieved a 50% reduction in HDRS score in 1 week, which persisted 1 month after in 55%. The amelioration involved an immediate and persistent decrease in suicide scores soon after the first total sleep deprivation cycle (F3,411 = 42.78, P < .00001). A positive history of suicide attempts was associated with worse early life stress and with worse suicide scores at baseline, but it did not influence response. Patients with current suicidal thinking or planning responded equally well (F3,42 = 20.70, P < .000001). Remarkably, however, nonresponders achieved a benefit, with significantly decreased final scores also including suicidality ratings (F3,120 = 6.55, P = .0004). Self-ratings showed the same pattern of change. Previous history of drug resistance did not hamper response. During the following month, 78 of 99 responders continued to stay well and were discharged from the hospital on lithium therapy alone. CONCLUSIONS The combination of total sleep deprivation, light therapy, and lithium is able to rapidly decrease depressive suicidality and prompt antidepressant response in drug-resistant major depression in the course of bipolar disorder.

Circadian clock gene Per3 variants influence the postpartum onset of bipolar disorder

Postpartum depression can mark the onset of bipolar disorder. The coding region of Per3 gene contains a variable-number tandem-repeat polymorphism, which has been shown to influence bipolar disorder onset and to affect breast cancer risk. We showed a relationship between Per3 polymorphism and postpartum depressive onset in bipolar disorder.