Ongoing lithium treatment prevents relapse after total sleep deprivation

Characterization of the central nervous system penetrant and selective purine P2X7 receptor antagonist JNJ-54175446 in patients with major depressive disorder

JNJ-54175446 is a selective purine P2X7 receptor (P2X7R) antagonist that attenuates microglial IL-1β/IL-18 release. In healthy volunteers, JNJ-54175446 suppressed peripheral interleukin (IL)-1β release, and attenuated dexamphetamine-induced improvements of mood and (visuo)motor performance in a human dexamphetamine-challenge paradigm. In depression, P2X7R inhibition may dampen immune-related dysregulation of mood. These results suggest that the impact of P2X7R inhibition is most prominent in situations where mood regulation is disrupted. Total sleep deprivation (TSD) results in an acute emotional perturbation, which yields a transient antidepressant effect. In the current study, TSD was applied as a behavioral challenge to investigate whether such effects could be modulated by JNJ-54175446. This was a double-blind, placebo-controlled, randomized study to assess the safety and pharmacokinetics of JNJ-54175446 and explore its effects in patients with single episode and recurrent major depressive disorder (MDD) (N = 69) and baseline total Inventory of Depressive Symptomatology Clinician Rated (IDS-C) > 30. Patients were randomized to receive JNJ-54175446 throughout the 10-day treatment period, placebo for days 1-3 followed by JNJ-54175446 or placebo throughout. All patients underwent 36 h of TSD starting on day three until the evening of day four. The early start group was hypothesized to experience a reduced effect from TSD whilst the late starting group was hypothesized to experience prolonged effects from the TSD. JNJ-54175446 was well-tolerated and adverse events were mild to moderate. JNJ-54175446 reduced IL-1β release by LPS-stimulated peripheral white blood cells in the presence of the P2X receptor agonist benzyl adenosine triphosphate (BzATP). JNJ-54175446 did not have a significant effect on mood as assessed using the Hamilton Depression Rating Scale, 17 items (HDRS17) and the Self-rated Quick Inventory of Depressive Symptoms (QIDS-SR). However, JNJ-54175446 blunted an acute reduction of anhedonia that occurred as a result of TSD, assessed by the Snaith-Hamilton Pleasure Scale (SHAPS) and the Probabilistic Instrumental Learning Task (PILT).

Antidepressant chronotherapeutics normalizes prefrontal 1H-MRS glutamate in bipolar depression

BACKGROUND

Dysfunctional glutamatergic neurotransmission has been proposed both, as a biological underpinning of mood disorder and as a target for rapid-acting antidepressant treatments. Total sleep deprivation and light therapy (TSD + LT) can prompt antidepressant response in drug-resistant bipolar depression. Here we explored the effects of TSD + LT on dorsolateral prefrontal cortex (DLPFC) glutamate and/or glutamine+glutamate (Glx) levels.

METHODS

We studied single voxel ¹H-MRS measures of DLPFC Glu and Glx levels of 48 healthy participants and 55 inpatients with a major depressive episode in course of Bipolar Disorder, a subset of which (N = 23) underwent three cycles of repeated TSD + LT and were evaluated before and after treatment. Treatment effects of mood and on Glu and Glx concentrations were analyzed in the context of the Generalized Linear Model (GLM), correcting for age, sex and ongoing lithium treatment.

RESULTS

Higher concentration of Glu (adjusted Z = -2189, p = 0,0285) and Glx (adjusted Z = -3,13, p = 0,0017) were observed in BD patients compared to HC. Treatment caused a significant rapid reduction of depressive symptom severity over time (F = 63.98, p < 0.01). Change in depression levels after TSD + LT treatment was significantly influenced by delta change in Glu levels (LR χ² = 4.619, p = 0.0316) and in Glx levels (LR χ² = 4.486, p = 0.0341).

CONCLUSION

A reduction in Glu and Glx levels associated with depression could contribute to the mechanism of action of TSD + LT, directly acting on glutamatergic neurons, or to the interaction between the glutamatergic system and dopamine (DA) and serotonin (5-HT) levels, known to be targeted by TSD. This is in line with several studies showing a glutamatergic modulation effects of antidepressants and mood stabilizing agents. This finding deepens our understanding of antidepressant effect of chronoterapeutics.

Rapid treatments for depression: Endocannabinoid system as a therapeutic target

Current first-line treatments for major depressive disorder (MDD), i.e., antidepressant drugs and psychotherapy, show delayed onset of therapeutic effect as late as 2-3 weeks or more. In the clinic, the speed of beginning of the actions of antidepressant drugs or other interventions is vital for many reasons. Late-onset means that depression, its related disability, and the potential danger of suicide remain a threat for some patients. There are some rapid-acting antidepressant interventions, such as sleep deprivation, ketamine, acute exercise, which induce a significant response, ranging from a few hours to maximally one week, and most of them share a common characteristic that is the activation of the endocannabinoid (eCB) system. Activation of this system, i.e., augmentation of eCB signaling, appears to have anti-depressant-like actions. This article puts the idea forward that the activation of eCB signaling represents a critical mechanism of rapid-acting therapeutic interventions in MDD, and this system might contribute to the development of novel rapid-acting treatments for MDD.

Meta-analysis of sleep deprivation in the acute treatment of bipolar depression

BACKGROUND

Sleep deprivation (SD) is an antidepressant intervention with multiple administration formats that has been investigated primarily with uncontrolled clinical trials and qualitative reviews of the literature. The validity and applicability of these findings to the treatment of bipolar depression (BPD) is uncertain.

METHODS

A PRISMA-based systematic review of the literature and meta-analysis were conducted to determine the efficacy of SD in the treatment of BPD and to identify moderator variables that influence response rate.

RESULTS

From a sample of 15 studies covering 384 patients, the overall, mean response rate to SD was 47.6% (CI 36.0%, 59.5%). This response rate compared post-SD to pre-SD depression scores, and not to a placebo control condition. Of several potential moderating variables examined, the use of adjunctive pharmacotherapy achieved statistical significance with response rates of 59.4% [CI 48.5, 69.5] for patients using adjunctive medication vs 27.4% [CI 17.8, 39.8] for patients not using adjunctive medication.

CONCLUSIONS

This meta-analysis of SD in the treatment of BPD found an overall, response rate of almost 50%, reinforcing earlier estimates of efficacy. The use of adjunctive pharmacotherapy had a statistically significant moderating effect on SD response suggesting that clinical practice should routinely pair these interventions. These findings provide a higher level of evidence supporting the use of SD, especially when used with medication, and should inform future management guidelines for the treatment of BPD.

Changes of white matter microstructure after successful treatment of bipolar depression

BACKGROUND

Diffusion tensor imaging (DTI) measures suggest a widespread alteration of white matter (WM) microstructure in patients with bipolar disorder (BD). The chronotherapeutic combination of repeated total sleep deprivation and morning light therapy (TSD+LT) can acutely reverse depressive symptoms in approximately 60% of patients, and it has been confirmed as a model antidepressant treatment to investigate the neurobiological correlates of rapid antidepressant response.

METHODS

We tested if changes in DTI measures of WM microstructure could parallel antidepressant response in a sample of 44 patients with a major depressive episode in course of BD, treated with chronoterapeutics for one week. We used both a tract-wise and a voxel-wise approach for the whole-brain extraction of DTI measures of WM microstructure: axial (AD), radial (RD), and mean diffusivity (MD), and fractional anisotropy (FA).

RESULTS

Compared to baseline level, at one-week follow up we observed a significant increase in average FA measures paralleled by a significant decrease in MD measures of several WM tracts including cingulum, corpus callosum, corona radiata, cortico-spinal tract, internal capsule, fornix and uncinate fasciculus. The degree of change was associated to clinical response.

CONCLUSIONS

This is the first study to show changes of individual DTI measures of WM microstructure in response to antidepressant treatment in BD. Our results add new evidence to warrant a role for chronotherapeutics as a first-line treatment for bipolar depression and contribute identifying generalizable neuroimaging-based biomarkers of antidepressant response.

Effectiveness of Sleep Deprivation in Treating Acute Bipolar Depression as Augmentation Strategy: A Systematic Review and Meta-Analysis

BACKGROUND

Bipolar disorder is a disabling disease characterized by the recurrence of mood episodes. Successful strategies for the acute treatment of bipolar depression are still a matter of controversy. Total sleep deprivation (TSD) has shown acute antidepressant effect; however, the prompt relapse of depressive symptoms after sleep recovery has been reported. Taking this into consideration, we aimed to address a twofold research question: what are the acute effects of adding TSD to pharmacological treatment and what are the acute and chronic effects of adding medications to TSD.

METHODS

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases were searched for clinical trials assessing bipolar depression and TSD. Two independent reviewers selected and classified 90 abstracts. The outcomes we assessed were change in Hamilton Depression Rating Scale (HDRS) or Montgomery-Asberg Depression Rating Scale (MADRS), sustained long-term response rate, treatment-emergent mania or hypomania, and tolerability (using dropout rates as a proxy). The compared groups were: TSD alone versus TSD plus medications and medications alone versus medications plus TSD. Data was analyzed using Stata 16.0.

RESULTS

Patients treated with TSD plus medications compared with medications alone showed a significant decrease in depressive symptomatology after one week (SMD -0.584 [95% CI -1.126 to -0.042], p = 0.03. Also, a significant decrease in depressive symptomatology (SMD -0.894 [95% CI -1.388 to -0.399], p < 0.001) was found in the group with TSD plus medications compared with TSD alone, at the 10^th day of treatment. We meta-analyzed the long-term effect of the TSD. It showed a sustained antidepressant effect (log OR = 2.365 (95% CI 0.95 to 3.779, p < 0.001) in the group where TSD was combined with medication when compared with patients treated only with TSD. Finally, no differences in tolerability (log OR = 0.234 (95% CI -1.164 to 1.632, p = 0.74) or affective switch were found.

CONCLUSION

Adding TSD to medications to bipolar depression treatment resulted in an augmentation in acute response. We also found that medications have a positive impact in acute response when added to TSD. Furthermore, this higher response rate was maintained after 3 months while keeping Lithium therapy.

The chronotherapeutic treatment of bipolar disorders: A systematic review and practice recommendations from the ISBD task force on chronotherapy and chronobiology

AIMS

To systematically review the literature on the efficacy and tolerability of the major chronotherapeutic treatments of bipolar disorders (BD)-bright light therapy (LT), dark therapy (DT), treatments utilizing sleep deprivation (SD), melatonergic agonists (MA), interpersonal social rhythm therapy (IPSRT), and cognitive behavioral therapy adapted for BD (CBTI-BP)-and propose treatment recommendations based on a synthesis of the evidence.

METHODS

PRISMA-based systematic review of the literature.

RESULTS

The acute antidepressant (AD) efficacy of LT was supported by several open-label studies, three randomized controlled trials (RCTs), and one pseudorandomized controlled trial. SD showed rapid, acute AD response rates of 43.9%, 59.3%, and 59.4% in eight case series, 11 uncontrolled, studies, and one RCT, respectively. Adjunctive DT obtained significant, rapid anti-manic results in one RCT and one controlled study. The seven studies on MA yielded very limited data on acute antidepressant activity, conflicting evidence of both antimanic and maintenance efficacy, and support from two case series of improved sleep in both acute and euthymic states. IPSRT monotherapy for bipolar II depression had acute response rates of 41%, 67%, and 67.4% in two open studies and one RCT, respectively; as adjunctive therapy for bipolar depression in one RCT, and efficacy in reducing relapse in two RCTs. Among euthymic BD subjects with insomnia, a single RCT found CBTI-BP effective in delaying manic relapse and improving sleep. Chronotherapies were generally safe and well-tolerated.

CONCLUSIONS

The outcome literature on the adjunctive use of chronotherapeutic treatments for BP is variable, with evidence bases that differ in size, study quality, level of evidence, and non-standardized treatment protocols. Evidence-informed practice recommendations are offered.

Perspectives in affective disorders: Clocks and sleep

Mood disorders are often characterised by alterations in circadian rhythms, sleep disturbances and seasonal exacerbation. Conversely, chronobiological treatments utilise zeitgebers for circadian rhythms such as light to improve mood and stabilise sleep, and manipulations of sleep timing and duration as rapid antidepressant modalities. Although sleep deprivation ("wake therapy") can act within hours, and its mood-elevating effects be maintained by regular morning light administration/medication/earlier sleep, it has not entered the regular guidelines for treating affective disorders as a first-line treatment. The hindrances to using chronotherapeutics may lie in their lack of patentability, few sponsors to carry out large multi-centre trials, non-reimbursement by medical insurance and their perceived difficulty or exotic "alternative" nature. Future use can be promoted by new technology (single-sample phase measurements, phone apps, movement and sleep trackers) that provides ambulatory documentation over long periods and feedback to therapist and patient. Light combinations with cognitive behavioural therapy and sleep hygiene practice may speed up and also maintain response. The urgent need for new antidepressants should hopefully lead to reconsideration and implementation of these non-pharmacological methods, as well as further clinical trials. We review the putative neurochemical mechanisms underlying the antidepressant effect of sleep deprivation and light therapy, and current knowledge linking clocks and sleep with affective disorders: neurotransmitter switching, stress and cortico-limbic reactivity, clock genes, cortical neuroplasticity, connectomics and neuroinflammation. Despite the complexity of multi-system mechanisms, more insight will lead to fine tuning and better application of circadian and sleep-related treatments of depression.

Depression in sleep disturbance: A review on a bidirectional relationship, mechanisms and treatment

Sleep disturbance is the most prominent symptom in depressive patients and was formerly regarded as a main secondary manifestation of depression. However, many longitudinal studies have identified insomnia as an independent risk factor for the development of emerging or recurrent depression among young, middle‐aged and older adults. This bidirectional association between sleep disturbance and depression has created a new perspective that sleep problems are no longer an epiphenomenon of depression but a predictive prodromal symptom. In this review, we highlight the treatment of sleep disturbance before, during and after depression, which probably plays an important role in improving outcomes and preventing the recurrence of depression. In clinical practice, pharmacological therapies, including hypnotics and antidepressants, and non‐pharmacological therapies are typically applied. A better understanding of the pathophysiological mechanisms between sleep disturbance and depression can help psychiatrists better manage this comorbidity.

Does early response predict subsequent remission in bipolar depression treated with repeated sleep deprivation combined with light therapy and lithium?

BACKGROUND

The combination of three cycles of sleep deprivation (SD), light therapy (LT), and lithium has recently been proposed as a possible first-line treatment for bipolar depression. However, it is unclear whether early improvement predicts final response/remission in bipolar depression treated with this regimen.

METHOD

We studied 220 consecutively admitted inpatients with a major depressive episode in the course of bipolar disorder. The relation between response to first SD and response/remission at the end of the treatment (day 6) was analyzed using logistic regression analysis. Severity of depression was rated using the Hamilton Depression Rating Scale (HDRS). Clinical response was defined as a ≥50% reduction in HDRS scores, and remission was defined as an HDRS score of ≤7.

RESULTS

Among the 217 completers, 67.7% showed response and 54.4% reached remission at the end of the treatment. Multiple logistic regression analysis revealed that response after first recovery sleep (day 2) predicted final response and remission at the end of the treatment with high odds ratios (10.9 for response and 8.2 for remission); however, response immediately after the first SD (day 1) did not predict final response or remission.

LIMITATIONS

Whether our results can be generalized to unipolar depression remains uncertain.

CONCLUSION

Clinical status after first recovery sleep is a strong predictor of successful final outcome in patients with bipolar depression treated with the combination of repeated SD, LT, and lithium. Recovery sleep may play a role in inducing the antidepressant effect associated with the success of treatment.

Treatment of severe depression – non-pharmacological aspects

Depression, in its severest forms, causes severe morbidity, has a high incidence of mortality and requires emergency treatment. In a previous article in this journal (Porter & Ferrier, 1999), we discussed the emergency treatment of severe depression by pharmacological means and electroconvulsive therapy (ECT). Here, we will discuss the contribution of non-pharmacological aspects of management to fast, effective and safe treatment of severe depression. We will also complete our review of this subject by examining the efficacy of some emerging therapeutic interventions for severe depression.

Ketamine-Induced Glutamatergic Mechanisms of Sleep and Wakefulness: Insights for Developing Novel Treatments for Disturbed Sleep and Mood

Ketamine, a drug with rapid antidepressant effects and well-described effects on slow wave sleep (SWS), is a useful intervention for investigating sleep-wake mechanisms involved in novel therapeutics. The drug rapidly (within minutes to hours) reduces depressive symptoms in individuals with major depressive disorder (MDD) or bipolar disorder (BD), including those with treatment-resistant depression. Ketamine treatment elevates extracellular glutamate in the prefrontal cortex. Glutamate, in turn, plays a critical role as a proximal element in a ketamine-initiated molecular cascade that increases synaptic strength and plasticity, which ultimately results in rapidly improved mood. In MDD, rapid antidepressant response to ketamine is related to decreased waking as well as increased total sleep, SWS, slow wave activity (SWA), and rapid eye movement (REM) sleep. Ketamine also increases brain-derived neurotrophic factor (BDNF) levels. In individuals with MDD, clinical response to ketamine is predicted by low baseline delta sleep ratio, a measure of deficient early night production of SWS. Notably, there are important differences between MDD and BD that may be related to the effects of diagnosis or of mood stabilizers. Consistent with its effects on clock-associated molecules, ketamine alters the timing and amplitude of circadian activity patterns in rapid responders versus non-responders with MDD, suggesting that it affects mood-dependent central neural circuits. Molecular interactions between sleep homeostasis and clock genes may mediate the rapid and durable elements of clinical response to ketamine and its active metabolite.

Discrepancy between subjective and objective severity as a predictor of response to chronotherapeutics in bipolar depression

BACKGROUND

Chronotherapeutic techniques (sleep deprivation and light therapy) are effective treatments for bipolar depression, but viable predictors of response for the daily clinical practice have not yet been established. The discrepancy between subjective and objective severity of the depressive syndrome has been proposed as a possible predictor of treatment outcome in depression. This study examined whether this discrepancy could predict response to chronotherapeutics in bipolar depression.

METHOD

We studied 149 consecutively admitted inpatients with a major depressive episode in course of bipolar disorder. Patients were treated with the combination of repeated sleep deprivation and bright light therapy. Severity of depression was evaluated using self-rated (Beck Depression Inventory: BDI) and observer-rated (Hamilton Depression Rating Scale: HDRS) measures. BDI-HDRS discrepancy score at baseline was calculated, and its associations with clinical response and with depressive cognitive distortions, as measured on the Cognitions Questionnaire, were examined.

RESULTS

Among the 147 completers, 66% responded to treatment (50% reduction of HDRS score). The response rate in patients with low discrepancy scores and in patients with high discrepancy scores were 80.2% and 48.5%, respectively. High BDI-HDRS discrepancy predicted negative response to treatment with odds ratio of 3.79 (95%CI: 1.61-8.93). BDI-HDRS discrepancy was positively associated with depressive cognitive distortions.

LIMITATIONS

Potential factors affecting the discrepancy and outcome other than cognitive distortion were not examined in this study.

CONCLUSION

Higher BDI-HDRS discrepancy can predict poorer response to chronotherapeutics in bipolar depression. The tendency to generalize hopelessness may be a factor influencing the link between the discrepancy and outcome.

Chronobiological Therapy for Mood Disorders

Chronobiological therapies for mood disorders include manipulations of the sleep-wake cycle such as sleep deprivation and sleep phase advance and the controlled exposure to light and darkness. Their antidepressant efficacy can overcome drug resistance and targets the core depressive symptoms including suicide, thus making them treatment options to be tried either alone or as adjunctive treatments combined with common psychopharmacological interventions. The specific pattern of mood change observed with chronobiological therapies is characterized by rapid and sustained effects, when used among themselves or combined with drugs. Effects sizes are the same reported for the most effective psychiatric treatments, but side effects are usually marginal or absent. New treatment protocols are developed to adapt them in different clinical settings. This review deals with the general principles of clinical chronobiology and the latest findings in this rapidly developing field.

A systematic review for the antidepressant effects of sleep deprivation with repetitive transcranial magnetic stimulation

BACKGROUND

Sleep deprivation (SD) and repetitive transcranial magnetic stimulation (rTMS) have been commonly used to treat depression. Recent studies suggest that co-therapy with rTMS and SD may produce better therapeutic effects than either therapy alone. Therefore, this study was to review the current findings to determine if rTMS can augment the therapeutic effects of SD on depression.

METHODS

Embase, JSTOR, Medline, PubMed, ScienceDirect, and the Cochrane Central Register of Controlled Trials were searched for clinical studies published between January 1985 and March 2015 using the search term "rTMS/repetitive transcranial magnetic stimulation AND sleep deprivation AND depress*". Only randomized and sham-controlled trials (RCTs) involving the combined use of rTMS and SD in depression patients were included in this systematic review. The scores of the Hamilton Rating Scale for Depression were extracted as primary outcome measures.

RESULTS

Three RCTs with 72 patients that met the inclusion criteria were included for the systematic review. One of the trials reported skewed data and was described alone. The other two studies, which involved 30 patients in the experimental group (SD + active rTMS) and 22 patients in the control group (SD + sham rTMS), reported normally distributed data. The primary outcome measures showed different results among the three publications: two of which showed great difference between the experimental and the control subjects, and the other one showed non-significant antidepressant effect of rTMS on SD. In addition, two of the included studies reported secondary outcome measures with Clinical Global Impression Rating Scale and a self-reported well-being scale which presented good improvement for the depressive patients in the experiment group when compared with the control. The follow-up assessments in two studies indicated maintained results with the immediate measurements.

CONCLUSIONS

From this study, an overview of the publications concerning the combined use of rTMS and SD is presented, which provides a direction for future research of therapies for depression. More studies are needed to confirm whether there is an augmentative antidepressant effect of rTMS on SD.

Sleep deprivation therapy for depression

Sleep deprivation (SD) is the most widely documented rapid-onset antidepressant therapy, targeting the broadly defined depressive syndrome. Although SD responses are transient, its effects can be sustained by concomitant medications (e.g., selective serotonin reuptake inhibitors and lithium) and circadian-related interventions (e.g., bright light and sleep phase advance). Thus, considering its safety, this technique can now be considered among the first-line antidepressant treatment strategies for patients affected by mood disorders. SD is a complex intervention and it should be considered multi-target in nature. Thus, the mechanisms explaining its antidepressant effect can be looked for on many levels, involving not only monoaminergic mechanisms but also sleep homeostatic and circadian mechanisms, glutamatergic mechanisms and synaptic plasticity.

Changes of cortical excitability as markers of antidepressant response in bipolar depression: preliminary data obtained by combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG)

BACKGROUND

It is still unclear which biological changes are needed to recover from a major depressive episode. Current perspectives focus on cortical synaptic neuroplasticity. Measures of cortical responses evoked by transcranial magnetic stimulation (TMS) change with sleep homeostasic pressure in humans and approximate measures of synaptic strength in animal models. Using repeated total sleep deprivation as a model of antidepressant treatment, we aimed to correlate recovery from depression with these measures of cortical excitability.

METHODS

We recorded electroencephalographic responses to TMS in the prefrontal cortex of 21 depressed inpatients with bipolar disorder treated with repeated sleep deprivation combined with light therapy. We performed seven TMS/electroencephalography sessions during one week and calculated three measures of cortical excitability.

RESULTS

Cortical excitability progressively increased during the antidepressant treatment and as a function of time awake. Higher values differentiated responders from non-responders at baseline and during and after treatment on all measures.

CONCLUSIONS

Changes in measures of cortical excitability parallel and predict antidepressant response to combined sleep deprivation and light therapy. Data suggest that promoting cortical plasticity in bipolar depression could be a major effect of successful antidepressant treatments, and that patients not responding could suffer a persistent impairment in their neuroplasticity mechanisms.

Adverse childhood experiences worsen cognitive distortion during adult bipolar depression

BACKGROUND

Cognitive distortion is a central feature of depression, encompassing negative thinking, dysfunctional personality styles and dysfunctional attitudes. It has been hypothesized that ACEs could increase the vulnerability to depression by contributing to the development of a stable negative cognitive style. Nevertheless, little research has been carried out on possible associations between adverse childhood experiences (ACEs) and cognitive distortion, and whether any gender differences exist.

AIM

The aim of this study was to examine the association between ACEs and cognitive distortions and possible differences between genders in a sample of patients affected by bipolar disorder.

METHOD

130 patients with bipolar disorder (BD) (46 men and 84 females), completed the Risky Family Questionnaire to assess ACEs and the Cognition Questionnaire (CQ) to assess cognitive distortions.

RESULTS

A positive association was found between ACE and the CQ total score. Investigating the 5 dimensions assessed through the CQ, only the dimension "generalization across situations" was significantly associated to ACE. An interaction between ACE and gender was found for "generalization across situations", while no differential effect among females and males was found for CQ total score.

CONCLUSION

This is the first study to report a relationship between negative past experiences and depressive cognitive distortions in subjects affected by BD. Growing in a family environment affected by harsh parenting seems to a cognitive vulnerability to depression; this effect is especially strong in females.

Basic sleep and circadian science as building blocks for behavioral interventions: a translational approach for mood disorders

Sleep and circadian functioning has been of particular interest to researchers focused on improving treatments for psychiatric illness. The goal of the present paper is to highlight the exciting research that utilizes basic sleep and circadian science as building blocks for intervention in the mood disorders. The reviewed evidence suggests that the sleep and circadian systems are a) disrupted in the mood disorders and linked to symptoms, b) open systems that can be modified, c) the focus of interventions which have been developed to effectively treat sleep disturbance within mood disorders, and d) intimately linked with mood, such that improvements in sleep are associated with improvements in mood. Although significant positive treatment effects are evident, more research is needed to fill the gap in our basic understanding of the relationship between sleep and mood.

Neuropsychological deficits in bipolar depression persist after successful antidepressant treatment

BACKGROUND

Bipolar disorder is a common disabling illness with a lifetime morbid risk of approximately 4%. Neuropsychological deficits constitute enduring trait-like features in bipolar disorder, are associated with each phase of the illness and persist also in euthymia. Total sleep deprivation (TSD) has been shown to cause rapid and sustained antidepressant effects in bipolar depression and to revert the biased self description and speed of information processing present in these patients. The aim of the study was to assess neuropsychological performances first in a sample of bipolar patients during a depressive episode compared to healthy controls and secondly to investigate if TSD treatment would change cognitive performances.

METHODS

One-hundred bipolar patients and 100 healthy controls were evaluated through the Brief Assessment of Cognition in Schizophrenia, 42 patients were assessed before and after TSD treatment.

RESULTS

Bipolar patients obtained significantly lower domain scores across the entire battery compared to healthy subjects. Cognitive deficits persisted in each function despite a clinical improvement of depressive symptomatology.

LIMITATIONS

Limitations of the study include issues such as generalizability, possible undetected past comorbidities, population stratification and ongoing medication.

CONCLUSIONS

This is the first study of the effect of TSD treatment on cognitive performance. TSD treatment improved clinical symptoms but not cognitive deficits however bipolar patients did not experience the well known worsening of performance observed in healthy controls after sleep loss.

Antidepressant chronotherapeutics for bipolar depression

Chronotherapeutics refers to treatments based on the principles of circadian rhythm organization and sleep physiology, which control the exposure to environmental stimuli that act on biological rhythms, in order to achieve therapeutic effects in the treatment of psychiatric conditions. It includes manipulations of the sleep-wake cycle such as sleep deprivation and sleep phase advance, and controlled exposure to light and dark. The antidepressant effects of chronotherapeutics are evident in difficult-to-treat conditions such as bipolar depression, which has been associated with extremely low success rates of antidepressant drugs in naturalistic settings and with stable antidepressant response to chronotherapeutics in more than half of the patients. Recent advances in the study of the effects of chronotherapeutics on neurotransmitter systems, and on the biological clock machinery, allow us to pinpoint its mechanism of action and to transform it from a neglected or “orphan” treatment to a powerful clinical instrument in everyday psychiatric practice.

Total sleep deprivation followed by sleep phase advance and bright light therapy in drug-resistant mood disorders

BACKGROUND

Drug-resistant depression is a major therapeutic issue in psychiatry and the development of non-drug therapies that treat drug-resistant depression is required. Sleep deprivation (SD) is a non-drug treatment classified as a form of chronotherapy in addition to bright light therapy (BLT) and sleep phase advance (SPA). Combined chronotherapy is hypothesized to improve drug-resistant depression. In this study, we investigated the benefits of total sleep deprivation (TSD) followed by SPA and BLT in drug-resistant depression alongside ongoing antidepressant medication and observed the added effectiveness of the combined chronotherapy.

METHODS

Thirteen drug-resistant inpatients affected by a major depressive episode were studied. They were treated by TSD followed by SPA (three days) and BLT (five days) with ongoing drug treatment. Effectiveness was rated using the Hamilton Rating Scale for Depression (HAM-D), the Zung Self-Rating Depression Scale (SDS), and the Visual Analogue Scale (VAS) over 3 weeks.

RESULTS

Significant improvements of depressive symptoms were observed in both objective mood ratings (HAM-D) and subjective mood ratings (SDS and VAS). Eight out of 13 patients maintained this responsiveness (50% or greater changes in HAM-D) across the study period. Moreover, no patients dropped out of the combined chronotherapy procedure.

LIMITATIONS

The study did not have a placebo group, and more subjects may be needed.

CONCLUSION

The trial of combined chronotherapy successfully induced rapid improvement in depressive symptoms in drug-resistant patients without early relapse or obvious side effects.

Outpatient triple chronotherapy for bipolar depression: case report

There is an urgent need for rapid, effective, and safe treatments for bipolar depression. Triple chronotherapy is a combination of sleep deprivation, sleep phase advance, and bright light therapy that has been shown to induce accelerated and sustained remissions in bipolar depression. This case report describes the first outpatient program designed to administer triple chronotherapy and reviews the organizational and clinical requirements for providing such care.

Rapid-acting antidepressant strategies: mechanisms of action

Current antidepressants are ineffective in many depressed patients. Thus there is an urgent need to develop treatment strategies which have significantly faster response, can be sustained and have minimal side-effects. This paper reviews clinical data, potential biomarkers, mechanisms of action and future research directions for two proven strategies that produce marked improvement in severe depressive symptoms within 48 h, ketamine and sleep deprivation therapy (SDT). These treatments provide unequivocal evidence that the depressive process can be rapidly reversed in a subgroup of patients. Seventeen ketamine studies in over 150 patients showed a rapid response. Low-dose intravenous ketamine produced mild psychotomimetic effects but response has not been effectively sustained. SDT has been investigated in over 60 studies with a 40-60% response rate within 48 h. Although SDT is often used in Europe to initiate a rapid response, it is less utilized within the USA, in part, because it has a short duration when administered alone. We review data concerning chronotherapeutic strategies of bright-light therapy (BLT) and sleep-phase advance (SPA) which successfully sustain the antidepressant efficacy of SDT. Evidence is further discussed that a significant group of mood disorders have abnormal circadian rhythms which are known to be controlled by clock genes. It is hypothesized that chronotherapeutic manipulations can reset clock genes and thus, abnormalities in circadian rhythms. Further findings are reviewed that ketamine, in addition to its role as an NMDA antagonist, can also alter circadian rhythms. Thus, ketamine may share a critical mechanism with SDT.

Treatment options for acute depression in bipolar disorder

OBJECTIVE

The burden of depression represents the most debilitating dimension for the majority of patients with bipolar disorder and dominates the long-term course of the illness. The purpose of this manuscript is to review the evidence base of the available treatment options for bipolar depression within two frequent clinical scenarios.

METHODS

The evidence is largely based on a systematic literature search and appraisal that was part of the development of the German Guideline for Bipolar Disorders. All relevant randomized controlled trials were critically evaluated.

RESULTS

Overall, the number of suitably controlled studies for the treatment of bipolar depression is relatively low. There are two common scenarios. Scenario A, if a patient with bipolar depression is currently not being treated with a mood-stabilizing agent (de novo depression, first or subsequent episode), then quetiapine or olanzapine are options, or alternatively, carbamazepine and lamotrigine can be considered. Antidepressants are an option for short-term use, but whether they are best administered as monotherapy or in combination with mood-stabilizing agents is still controversial. In practice, most clinicians use antidepressants in combination with an antimanic agent. Scenario B, if a patient is already being treated optimally with a mood-stabilizing agent (good adherence and appropriate dose) such as lithium, lamotrigine is an option. There is no evidence for additional benefit from antidepressants where a patient is already being treated with a mood stabilizer; however, in practice an antidepressant is often trialled. Efficient psychotherapy is an important part of the treatment regimen and should span all phases of the illness.

CONCLUSIONS

Treatment decisions in bipolar depression involve a range of different pharmacological and non-pharmacological options. Monitoring potential unwanted effects and the appropriateness of treatment can help to effectively balance benefits and risks in individual situations. However, the quality of the assessment and reporting of risks in clinical trials need to be improved to better inform treatment decisions.

Sleep deprivation in mood disorders

Growing clinical evidence in support of the efficacy and safety of sleep deprivation (SD), and its biological mechanisms of action suggest that this technique can now be included among the first-line antidepressant treatment strategies for mood disorders. SD targets the broadly defined depressive syndrome, and can be administered according to several different treatment schedules: total versus partial, single versus repeated, alone or combined with antidepressant drugs, mood stabilizers, or other chronotherapeutic techniques, such as light therapy and sleep phase advance. The present review focuses on clinical evidence about the place of SD in therapy, its indications, dosage and timing of the therapeutic wake, interactions with other treatments, precautions and contraindications, adverse reactions, mechanism of action, and comparative efficacy, with the aim of providing the clinical psychiatrist with an updated, concise guide to its application.

Opposite effects of suicidality and lithium on gray matter volumes in bipolar depression

BACKGROUND

Mood disorders are associated with the highest increase of attempted and completed suicide. Suicidality in major depressive disorder and in schizophrenia has been associated with reduced gray matter volumes in orbitofrontal cortex. Lithium reduces the suicide risk of patients with bipolar disorder (BD) to the same levels of the general population, and can increase GM volumes. We studied the effect of a positive history of attempted suicide and ongoing lithium treatment on regional GM volumes of patients affected by bipolar depression.

METHODS

With a correlational design, we studied 57 currently depressed inpatients with bipolar disorder: 19 with and 38 without a positive history of suicide attempts, 39 unmedicated and 18 with ongoing lithium treatment. Total and regional gray matter volumes were assessed using voxel-based morphometry.

RESULTS

Total GM volume is inversely correlated with depression severity. A positive history of suicide attempts was associated with higher stress in early life. Suicide attempters showed reduced GM volumes in several brain areas including dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate, superior temporal cortex, parieto-occipital cortex, and basal ganglia. Long term lithium treatment was associated with increased GM volumes in the same areas where suicide was associated with decreased GM.

CONCLUSIONS

Reduced GM volumes in critical cortical areas of suicidal patients could be a biological correlate of an impaired ability to associate choices and outcomes and to plan goal-directed behaviors based on a lifetime historical perspective, which, coupled with mood-congruent depressive cognitive distortions, could lead to more hopelessness and suicide. Lithium could exert its specific therapeutic effect on suicide by acting in the same areas.

Modafinil reduces microsleep during partial sleep deprivation in depressed patients

OBJECTIVE

Sleep deprivation (SD) can induce a prompt decrease in depressive symptoms within 24h. Following the recovery night, however, a relapse into depression occurs in most patients. Recovery sleep, naps and even very short episodes of sleep (microsleep; MS) during SD have been shown to provoke a rapid relapse into depression. This study tested the hypothesis that modafinil reduces MS during SD and stabilizes the treatment response to PSD compared to placebo.

METHODS

A total of 28 patients (13 men, 15 women; age 45.1+/-12.1 years) with a major depressive episode and a cumulative daytime microsleep of five or more minutes were investigated using a double-blind placebo-controlled study design. All patients were treated with a stable mirtazapine monotherapy. A partial SD (PSD) was performed after one week. Additional morning treatment with modafinil vs. placebo started during PSD and was maintained over two weeks. Sleep-EEG and MS episodes were recorded with a portable EEG. Depression severity was assessed using the Hamilton Depression Rating Scale before, during and after PSD and at follow-ups after one and two weeks.

RESULTS

Patients treated with modafinil showed significantly reduced microsleep during PSD (11.63+/-15.99 min) compared to the placebo group (47.77+/-65.31 min). This suppression of MS was not associated with the antidepressive effect of PSD.

CONCLUSIONS

Compared to placebo, modafinil was efficient in reducing daytime microsleep following partial sleep deprivation but did not enhance the antidepressive effects of PSD and did not stabilize antidepressive effects over two weeks.

The Timing of Antidepressant Effects: A Comparison of Diverse Pharmacological and Somatic Treatments

Currently available antidepressants used to treat major depressive disorder (MDD) unfortunately often take weeks to months to achieve their full effects, commonly resulting in considerable morbidity and increased risk for suicidal behavior. Our lack of understanding of the precise cellular underpinnings of this illness and of the mechanism of action of existing effective pharmacological treatments is a large part of the reason that therapies with a more rapid onset of antidepressant action (ROAA) have not been developed. Other issues that need to be addressed include heterogeneous clinical concepts and statistical models to measure rapid antidepressant effects. This review describes the timing of onset of antidepressant effects for various therapies used to treat MDD. While several agents produce earlier improvement of depressive symptoms (defined as occurring within one week), the response rate associated with such agents can be quite variable. These agents include both currently available antidepressants as well as other pharmacological and non-pharmacological interventions. Considerably fewer treatments are associated with ROAA, defined as occurring within several hours or one day. Treatment strategies for MDD whose sustained antidepressant effects manifest within hours or even a few days would have an enormous impact on public health.

Rapid and sustained antidepressant response with sleep deprivation and chronotherapy in bipolar disorder

BACKGROUND

The development of a rapid-acting and sustainable treatment for bipolar disorder (BPD) depression has been a goal for decades. The most widely documented rapid-onset antidepressant therapy is sleep deprivation (SD), which acts within 24-48 hours in 40%-60% of depressed patients. Conventional antidepressants usually require 2-8 weeks to meet response criteria. The delay, which may prolong suffering and increase suicidal risk, underlines the urgency of alternative treatment strategies. This study evaluates the combined efficacy of three established circadian-related treatments (SD, bright light [BL]), sleep phase advance [SPA]) as adjunctive treatment to lithium and antidepressants.

METHODS

Forty-nine BPD patients were randomly assigned to a chronotherapeutic augmentation (CAT; SD+ BL+ SPA) or to a medication-only (MED) group. Clinical outcome was assessed using the Hamilton Rating Scale for Depression.

RESULTS

Significant decreases in depression in the CAT versus MED patients were seen within 48 hours of SD and were sustained over a 7-week period.

CONCLUSIONS

This is the first study to demonstrate the benefit of adding three noninvasive circadian-related interventions to SD in medicated patients to accelerate and sustain antidepressant responses and provides a strategy for the safe, fast-acting, and sustainable treatment of BPD.

Circadian rhythm disturbances in depression

OBJECTIVE

The aim of this article is to review progress in understanding the mechanisms that underlie circadian and sleep rhythms, and their role in the pathogenesis and treatment of depression.

METHODS

Literature was selected principally by Medline searches, and additional reports were identified based on ongoing research activities in the authors' laboratory.

RESULTS

Many physiological processes show circadian rhythms of activity. Sleep and waking are the most obvious circadian rhythms in mammals. There is considerable evidence that circadian and sleep disturbances are important in the pathophysiology of mood disorders. Depressed patients often show altered circadian rhythms, sleep disturbances, and diurnal mood variation. Chronotherapies, including bright light exposure, sleep deprivation, and social rhythm therapies, may be useful adjuncts in non-seasonal and seasonal depression. Antidepressant drugs have marked effects on circadian processes and sleep.

CONCLUSIONS

Recent progress in understanding chronobiological and sleep regulation mechanisms may provide novel insights and avenues into the development of new pharmacological and behavioral treatment strategies for mood disorders.

Rapid onset of antidepressant action: a new paradigm in the research and treatment of major depressive disorder

OBJECTIVE

Current therapeutics of depression are similar in their time to antidepressant action and often take weeks to months to achieve response and remission, which commonly results in considerable morbidity and disruption in personal, professional, family, and social life, as well as risk for suicidal behavior. Thus, treatment strategies presenting a rapid improvement of depressive symptoms--within hours or even a few days--and whose effects are sustained would have an enormous impact on public health. This article reviews the published data related to different aspects of rapid improvement of depressive symptoms.

DATA SOURCES

Literature for this review was obtained through a search of the MEDLINE database (1966-2007) using the following keywords and phrases: rapid response, antidepressant, time to, glutamate, sleep, therapeutics, latency, and depression. The data obtained were organized according to the following topics: clinical relevance and time course of antidepressant action, interventions showing evidence of rapid response and its potential neurobiological basis, and new technologies for better understanding rapid anti-depressant actions.

DATA SYNTHESIS

A limited number of prospective studies evaluating rapid antidepressant actions have been conducted. Currently, only a few interventions have been shown to produce antidepressant response in hours or a few days. The neurobiological basis of these rapid antidepressant actions is only now being deciphered.

CONCLUSIONS

Certain experimental treatments can produce antidepressant response in a much shorter period of time than existing medications. Understanding the molecular basis of these experimental interventions is likely to lead to the development of improved therapeutics rather than simply furthering our knowledge of current standard antidepressants.

Chronotherapeutics in a psychiatric ward

Psychiatric chronotherapeutics is the controlled exposure to environmental stimuli that act on biological rhythms in order to achieve therapeutic effects in the treatment of psychiatric conditions. In recent years some techniques (mainly light therapy and sleep deprivation) have passed the experimental developmental phase and reached the status of powerful and affordable clinical interventions for everyday clinical treatment of depressed patients. These techniques target the same brain neurotransmitter systems and the same brain areas as do antidepressant drugs, and should be administered under careful medical supervision. Their effects are rapid and transient, but can be stabilised by combining techniques among themselves or together with common drug treatments. Antidepressant chronotherapeutics target the broadly defined depressive syndrome, with response and relapse rates similar to those obtained with antidepressant drugs, and good results are obtained even in difficult-to-treat conditions such as bipolar depression. Chronotherapeutics offer a benign alternative to more radical treatments of depression for the treatment of severe depression in psychiatric wards, but with the advantage of rapidity of onset.

Limitations of current medical treatments for depression: disturbed circadian rhythms as a possible therapeutic target

The proportion of diagnosed depressives prescribed antidepressants has increased markedly over the last 20 years, mainly following the introduction of the selective serotonin reuptake inhibitors. However, currently available antidepressants have notable limitations, relating to their only moderate efficacy relative to placebo, relatively slow onset of action, possible withdrawal symptoms, and problems of compliance. Sleep disturbances are often used to identify newly presenting depressive patients, and may be part of a more general alteration of bodily rhythms. There are links between pharmacological treatments and circadian rhythms in depression, which might represent another, new option for the development of a therapeutic approach to depression treatment. Many antidepressants affect sleep, some are sedative, and others have been used specifically in severely insomniac depressives. Disturbances in circadian rhythms may be an integral part of depressive mechanisms, and normalising them via an innovative mechanism of antidepressant action may be a fruitful avenue in the search for improved antidepressant agents.

The influence of Serotonin Transporter Promoter Polymorphism (SERTPR) and other polymorphisms of the serotonin pathway on the efficacy of antidepressant treatments

The definition of a genetic liability profile for specific antidepressant treatment will soon be available offering considerable help in early detection of effective therapy in affective disorders. The search for genetic factors predisposing to drug response or side-effects in affective disorders started only in the last few years. The efficacy of antidepressant action was associated with several polymorphisms, located on coding genes of proteins thought to be involved in the different mechanisms of action of antidepressant treatments. Among these, gene variants in sequences of serotonin pathway proteins were candidate, both for the well known evidence of its involvement in the development of depressive symptomathology and for the wide-world use of selective serotonin reuptake inhibitors as first choice treatment of depression. A polymorphism in the promoter region of the serotonin transporter (SERTPR) was independently associated with efficacy for a range of treatments, other polymorphism located on the tryptophan hydroxylase gene, 5-HT2a receptor and G-protein beta 3 showed some association, while other candidate genes were not associated with treatment efficacy. Possible liability genes controlling at least to some extent both acute and long-term treatment were identified, and the further objective is to identify other candidate genes in order to define individualized treatments according to genetic profile in a future. The present paper reviews the pharmacogenetic studies published to date, focusing the attention on the serotonergic pathway.

Depressive syndrome in major psychoses: a study on 1351 subjects

The aim of this study was to investigate depressive symptomatology across distinct major psychiatric disorders. A total of 1351 subjects affected by major depressive disorder (MDD = 389), bipolar disorder (BP = 511), delusional disorder (DD = 93) and schizophrenia (SKZ = 358) were included in our study. Subjects were assessed using the Operational Criteria for Psychotic Illness checklist (OPCRIT). The most frequently represented depressive symptoms in MDD were Loss of energy/tiredness, Loss of pleasure, Poor concentration, and Sleep disorders. Compared with MDD, BP had higher occurrences of Agitated activity, Excessive sleep, and Increased appetite and/or Weight gain, as well as lower Loss of pleasure. In our sample, 32.3% and 26.8% of DD and SKZ, respectively, had quite consistent depressive symptomatology, with at least four or more depressive symptoms. The most common depressive symptoms were Sleep disorders, Poor concentration and Loss of energy/Tiredness, followed by Psychomotor symptoms in SKZ only. Excessive self-reproach, Suicidal ideation, and Appetite and/or Weight changes were more specific to mood disorders. Finally, compared with SKZ, DD suffered from more depressive symptoms and had more severe depressive symptomatology. A quite consistent level of depressive symptomatology is therefore present in subpopulations of delusional and schizophrenic subjects other than in affective subjects. We identified some symptoms that are common across all major psychoses and symptoms that are more specific to each group.

Influence of CLOCK gene polymorphism on circadian mood fluctuation and illness recurrence in bipolar depression

Recent studies showed that a polymorphism (T to C nucleotide substitution) in the 3' flanking region of the human CLOCK gene is associated with diurnal preferences of human healthy subjects, with higher "eveningness" in subjects carrying at least one copy of the C allele. We investigated the possible role of CLOCK gene polymorphism in the regulation of diurnal mood fluctuations during a major depressive episode. Sample (n = 101) was collected, in the context of previously reported trials, among patients affected by bipolar disorder type I, depressive episode without psychotic features, free of psychotropic medications. Perceived mood levels were assessed three times a day with self-administered visual analogue scales. Genotype groups showed no significant difference in diurnal mood fluctuations. When stratifying the sample by including only patients with an adequate period of observation (duration of illness higher than 5 years, n = 69), we post-hoc observed a significantly higher recurrence rate in homozygotes for the C variant, which was almost double than that of the other genotype groups. This preliminary observation leads to hypothesize a role for the CLOCK gene polymorphism in the regulation of long-term illness recurrence in bipolar disorder. Given the post-hoc nature of the finding, replication in independent samples is necessary to confirm it.

Predicting response to lithium in mood disorders: role of genetic polymorphisms

Lithium is considered to be the first choice mood stabilizer in recurrent mood disorders. Its widespread and large-scale use is the result of its proven efficacy. In spite of this fact, patients have been observed to show a variable response to lithium treatment: in some cases it is completely effective in preventing manic or depressive relapses, while in other cases it appears to show no influence on the disease course. The possible definition of a genetic liability profile for adverse effects and efficacy will be of great help, as lithium therapy needs at least 6 months to be effective in stabilizing mood disorders. During the last few years, a number of groups have reported possible liability genes. Lithium long-term prophylactic efficacy has been associated with serotonin transporter protein, tryptophan hydroxylase and inositol polyphosphate 1-phosphatase variants. A number of other candidate genes and anonymous markers did not yield positive associations. Therefore, even if some positive results have been reported, no unequivocal susceptibility gene for lithium efficacy has been identified. Although the available data may not currently allow a meaningful prediction of lithium response, future research is aimed at the development of individualized treament of mood disorders, including the possibility of 'pharmacological genetic counseling'.

Clinical features of antidepressant associated manic and hypomanic switches in bipolar disorder

The present study investigated possible clinical differences between bipolar patients with and without manic or hypomanic switch during antidepressant (AD) treatment. The authors undertook a retrospective assessment of 169 individuals affected by bipolar disorder type I (BP I: n=96) and II (BP II: n=73) who experienced at least one manic or hypomanic episode following depression without any interposed normothymic period ("manic switch") during AD therapy. They were compared with a sex, age (+/-5 years), and ethnicity-matched group of 247 subjects, randomly selected from our pool of bipolar subjects who have never had manic switches. Only 2 of the 169 patients had had spontaneous switches before the AD-related one. Switched subjects were marginally older (t=-2.65, df=414, P=.008) compared to not switched and less frequently delusional (chi2=13.86, P=.0002). Polarity of the onset episode was more frequently depressive in switched patients (chi2=21.93, P=.00002), which had also less previous manic episodes than not switched (t=3.44, df=332, P=.0006). Those differences were more pronounced in the BP I subsample. Switched patients were more frequently BP I (chi2=29.66; P<.00001). Maintenance with mood stabilizers appears to be a strong protective factor; in fact, of the 124 individuals undertaking a mood stabilizer therapy, 21 had a switch and 103 had no switches (chi2=41.10, P<.000001). In conclusion, some clinical variables, such as the number of manic episodes, the presence of delusions, the polarity of onset episode, and the mood-stabilizing treatment, may be involved in AD-related switches. Further studies are required to investigate the causal relationships between those factors.

Clinical and demographic features of mood disorder subtypes

The aim of this study was to investigate demographic, clinical and symptomatologic features of the following mood disorder subtypes: bipolar disorder I (BP-I); bipolar disorder II (BP-II); major depressive disorder, recurrent (MDR); and major depressive episode, single episode (MDSE). A total of 1832 patients with mood disorders (BP-I=863, BP-II=141, MDR=708, and MDSE=120) were included in our study. The patients were assessed using structured diagnostic interviews and the operational criteria for psychotic illness checklist (n=885), the Hamilton depression rating scale (n=167), and the social adjustment scale (n=305). The BP-I patients were younger; had more hospital admissions; presented a more severe form of symptomatology in terms of psychotic symptoms, disorganization, and atypical features; and showed less insight into their disorder than patients in the other groups. Compared with the major depressive subgroups, BP-I patients were more likely to have an earlier age at onset, an earlier first lifetime psychiatric treatment, and a greater number of illness episodes. BP-II patients had a higher suicide risk than both BP-I and MDSE patients. MDSE patients presented less severe symptomatology, lower age at observation, and a higher number of males. The retrospective approach and the selection constraints due to the inclusion criteria are the main limitations of the study. Our data support the view that BP-I disorder is quite different from the remaining mood disorders from a demographic and clinical perspective, with BP-II disorder having an intermediate position to MDR and MDSE, that is, as a less severe disorder. This finding may help in the search for the biological basis of mood disorders.