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.

A Homer 1 gene variant influences brain structure and function, lithium effects on white matter, and antidepressant response in bipolar disorder: A multimodal genetic imaging study.

BACKGROUND: The Homer family of postsynaptic scaffolding proteins plays a crucial role in glutamate-mediated synaptic plasticity, a phenotype associated with Bipolar Disorder (BD). Homer is a target for antidepressants and mood stabilizers. The AA risk genotype of the Homer rs7713917 A>G SNP has been associated with mood disorders and suicide, and in healthy humans with brain function. Despite the evidence linking Homer 1 gene and function to mood disorder, as well as its involvement in animal models of depression, no study has yet investigated the role of Homer in bipolar depression and treatment response. METHODS: We studied 199 inpatients, affected by a major depressive episode in course of BD. 147 patients were studied with structural MRI of grey and white matter, and 50 with BOLD functional MRI of emotional processing. 158 patients were treated with combined total sleep deprivation and light therapy. RESULTS: At neuroimaging, patients with the AA genotype showed lower grey matter volumes in medial prefrontal cortex, higher BOLD fMRI neural responses to emotional stimuli in anterior cingulate cortex, and lower fractional anisotropy in bilateral frontal WM tracts. Lithium treatment increased axial diffusivity more in AA patients than in G*carriers. At clinical evaluation, the same AA homozygotes showed a worse antidepressant response to combined SD and LT. CONCLUSIONS: rs7713917 influenced brain grey and white matter structure and function in BD, long term effects of lithium on white matter structure, and antidepressant response to chronotherapeutics, thus suggesting that glutamatergic neuroplasticity and Homer 1 function might play a role in BD psychopathology and response to treatment.

Higher Baseline Proinflammatory Cytokines Mark Poor Antidepressant Response in Bipolar Disorder.

BACKGROUND: The clinical relevance of raised levels of circulating cytokines in bipolar disorder is still unclear. Cytokines influence neurotransmitters, neuroplasticity, and white matter integrity. An inconsistent literature suggests that higher cytokine levels could hamper antidepressant response. Total sleep deprivation (TSD) and light therapy (LT) prompt a rapid antidepressant response and can provide a model treatment to study predictors of response. METHODS: We studied at baseline 15 immune-regulating compounds in 37 consecutively admitted inpatients with a major depressive episode in the course of bipolar disorder (DSM-5 criteria) and in 24 controls. Thirty-one patients (84%) had a lifetime history of drug resistance. Patients were administered 3 TSD + LT cycles in 1 week (study period: 2010-2012). Data were analyzed with age- and false-discovery-rate-corrected analysis of variance and were tested as predictors in a regressive model. RESULTS: Twenty-three patients (62%) responded to treatment (Inventory of Depressive Symptomatology IDS-C score < 12). Five highly intercorrelated compounds (IL-8, MCP-1, IFN-γ, IL-6, TNF-α) showed higher levels in nonresponder patients as compared to responders, corrected for multiple comparisons (respectively F = 6.138, PFDR = .0134; F = 6.197, PFDR = .0134; F = 4.785, PFDR = .0255; F = 3.782, PFDR = .0441; F = 3.764, PFDR = .0441). A principal component analysis identified a single component that explained 84% of variance of these cytokines (Q² = 0.15), and a high factor score significantly predicted worse response (b = -0.692; W = 4.34, P = .037). A higher body mass index correlated with higher cytokines (r = 0.430, P = .010), indirectly hampering response (b = -0.0192, P = .013). CONCLUSIONS: Proinflammatory compounds reflecting an M1-like proinflammatory state of monocytes/macrophages are associated with a poor response to antidepressant TSD + LT treatment in bipolar depression.

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.

Stem Cell Factor (SCF) is a putative biomarker of antidepressant response.

Growth factors involved in neurogenesis and neuroplasticity could play a role in biological processes that drive depression recovery. Combined total sleep deprivation and morning light therapy (TSD + LT) can acutely reverse depressive symptoms, thus allowing to investigate the neurobiological correlates of antidepressant response. We tested if changes on plasma levels of Brain Derived Neurotrophic Factor (BDNF), S100 calcium binding protein B (S100-B), Stem Cell Factor (SCF), Insulin-like Growth Factor-Binding Protein 2 (IGFBP-2), Epidermal Growth Factor (EGF), Platelet-Derived Growth Factor-BB (PDGF-BB), and Vascular Endothelial Growth Factor (VEGF) are associated with response to TSD + LT in 26 inpatients affected by a major depressive episode in the course of bipolar disorder. Regional grey matter (GM) volumes were assessed at baseline, and BOLD fMRI neural responses to a moral valence decision task were recorded before and after treatment. 61.5 % of patients responded to treatment. SCF plasma levels increased significantly more in responders, and correlated with GM volumes in frontal and parietal cortical areas. The pattern of change of SCF also associated with both GM volumes and changes of BOLD fMRI neural responses in the anterior cingulate and medial prefrontal cortex. SCF is both a hematopoietic growth factor and a neurotrophic factor, involved in neuron-neuron and neuron-(micro) glia interactions, fostering neuronal growth and an anti-inflammatory milieu. We correlated SCF levels with antidepressant response and with functional and structural MRI measures in cortical areas that are involved in the cognitive generation and control of affect. SCF may be a candidate growth factor that contributes to neurotrophic and immune effects that are involved in the process of remission/recovery from depression.

Sleep homeostatic pressure and PER3 VNTR gene polymorphism influence antidepressant response to sleep deprivation in bipolar depression.

BACKGROUND: Combined Total sleep deprivation (TSD) and light therapy (LT) cause a rapid improvement in bipolar depression which has been hypothesized to be paralleled by changes in sleep homeostasis. Recent studies showed that bipolar patients had lower changes of EEG theta power after sleep and responders to antidepressant TSD+LT slept less and showed a lower increase of EEG theta power then non-responders. A polymorphism in PER3 gene has been associated with diurnal preference, sleep structure and homeostatic response to sleep deprivation in healthy subjects. We hypothesized that the individual variability in the homeostatic response to TSD could be a correlate of antidepressant response and be influenced by genetic factors. METHODS: We administered three TSD+LT cycles to bipolar depressed patients. Severity of depression was rated on Hamilton Depression Rating Scale. Actigraphic recordings were performed in a group of patients. RESULTS: PER3 polymorphism influenced changes in total sleep time (F=2.24; p=0.024): while PER3(4/4) and PER3(4/5) patients showed a reduction in it after treatment, PER3(5/5) subjects showed an increase of about 40min, suggesting a higher homeostatic pressure. The same polymorphism influenced the change of depressive symptomatology during treatment (F=3.72; p=0.028). LIMITATIONS: Sleep information was recorded till the day after the end of treatment: a longer period of observation could give more information about the possible maintenance of allostatic adaptation. CONCLUSIONS: A higher sleep homeostatic pressure reduced the antidepressant response to TSD+LT, while an allostatic adaptation to sleep loss was associated with better response. This process seems to be under genetic control.

Successful antidepressant chronotherapeutics enhance fronto-limbic neural responses and connectivity in bipolar depression.

The identification of antidepressant response predictors in bipolar disorder (BD) may provide new potential enhancements in treatment selection. Repeated total sleep deprivation combined with light therapy (TSD+LT) can acutely reverse depressive symptoms and has been proposed as a model antidepressant treatment. This study aims at investigating the effect of TSD+LT on effective connectivity and neural response in cortico-limbic circuitries during implicit processing of fearful and angry faces in patients with BD. fMRI and Dynamic Causal Modeling (DCM) were combined to study the effect of chronotherapeutics on neural responses in healthy controls (HC, n = 35) and BD patients either responder (RBD, n = 26) or non responder (nRBD, n = 11) to 3 consecutive TSD+LT sessions. Twenty-four DCMs exploring connectivity between anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), Amygdala (Amy), fusiform gyrus and visual cortex were constructed. After treatment, patients significantly increased their neural responses in DLPFC, ACC and insula. nRBD showed lower baseline and endpoint neural responses than RBD. The increased activity in ACC and in medial prefrontal cortex, associated with antidepressant treatment, was positively associated with the improvement of depressive symptomatology. Only RBD patients increased intrinsic connectivity from DLPFC to ACC and reduced the modulatory effect of the task on Amy-DLPFC connection. A successful antidepressant treatment was associated with an increased functional activity and connectivity within cortico-limbic networks, suggesting the possible role of these measures in providing possible biomarkers for treatment efficacy.

Disruption of white matter integrity marks poor antidepressant response in bipolar disorder.

BACKGROUND: Changes of white matter (WM) microstructure have been proposed as structural biomarkers of 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 proposed as a model antidepressant treatment to investigate the neurobiological correlates of rapid antidepressant response. METHODS: We tested if baseline DTI measures can predict response to treatment in 70 in-patients affected by a major depressive episode in the course of BD, treated with chronotherapeutics for one week. We performed whole-brain tract-based spatial statistics with threshold-free cluster enhancement for the DTI measures of WM microstructure integrity: fractional anisotropy, axial, radial, and mean diffusivity. RESULTS: Increased mean and radial water diffusivity correlated with poor antidepressant response to TSD+LT in core WM tracts which are crucial for the functional integrity of the brain, including corpus callosum, corona radiata, cingulum bundle, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and thalamic radiation. LIMITATIONS: Limitations include issues such as generalizability, possible population stratification, medications and their effects on DTI measures, and no placebo control for chronotherapeutics. We could not consider other factors such as gene-environment interactions. CONCLUSIONS: The association of increased radial and mean diffusivity with poor response to chronotherapeutic treatment warrants interest for the study of DTI measures of WM microstructure as markers for treatment response in bipolar depression.

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.

Acute antidepressant response to sleep deprivation combined with light therapy is influenced by the catechol-O-methyltransferase Val(108/158)Met polymorphism.

Catechol-O-methyltransferase (COMT) inactivates norepinephrine and dopamine via methyl conjugation, and a G-A transition in the COMT gene (rs4680) influences the enzyme activity. It is a current area of debate whether rs4680 can influence antidepressant response in major depressive disorder, and whether this influence extends to bipolar depression. Chronotherapeutic interventions, such as sleep deprivation and light therapy, are multi-target in nature and are effective in bipolar depression. Here we studied the effect of rs4680 on response to sleep deprivation combined with light therapy (36 h awake followed by a night of undisturbed sleep, with 10,000 lx light administered for 30 min during the night awake and upon awakening) in 87 bipolar depressed inpatients. Patients who were homozygotic for the Val/Val variant showed a significantly less efficient antidepressant effect after the night awake than those who were heterozygotic and homozygotic for the Met variant. This effect of rs4680 is similar to its observed influence on response to serotonergic and noradrenergic drug treatments in major depressive disorder. This is the first study reporting an influence of rs4680 on antidepressant response in bipolar depression. This finding supports the hypothesis of a major role for catecholamines in the mechanism of action of chronotherapeutics, and for rs4680 in modulating this effect.