The functional neuroanatomy of the placebo effect

OBJECTIVE: Administration of placebo can result in a clinical response indistinguishable from that seen with active antidepressant treatment. Functional brain correlates of this phenomenon have not been fully characterized. METHOD: Changes in brain glucose metabolism were measured by using positron emission tomography in hospitalized men with unipolar depression who were administered placebo as part of an inpatient imaging study of fluoxetine. Common and unique response effects to administration of placebo or fluoxetine were assessed after a 6-week, double-blind trial. RESULTS: Placebo response was associated with regional metabolic increases involving the prefrontal, anterior cingulate, premotor, parietal, posterior insula, and posterior cingulate and metabolic decreases involving the subgenual cingulate, parahippocampus, and thalamus. Regions of change overlapped those seen in responders administered active fluoxetine. Fluoxetine response, however, was associated with additional subcortical and limbic changes in the brainstem, striatum, anterior insula, and hippocampus, sources of efferent input to the response-specific regions identified with both agents. CONCLUSIONS: The common pattern of cortical glucose metabolism increases and limbic-paralimbic metabolism decreases in placebo and fluoxetine responders suggests that facilitation of these changes may be necessary for depression remission, regardless of treatment modality. Clinical improvement in the group receiving placebo as part of an inpatient study is consistent with the well-recognized effect that altering the therapeutic environment may significantly contribute to reducing clinical symptoms. The additional subcortical and limbic metabolism decreases seen uniquely in fluoxetine responders may convey additional advantage in maintaining long-term clinical response and in relapse prevention.     

Regional cerebral blood flow changes after low-frequency transcranial magnetic stimulation of the right dorsolateral prefrontal cortex in treatment-resistant depression

Several studies have proved that low-frequency transcranial magnetic stimulation (TMS) of the right dorsolateral prefrontal cortex (DLPFC) showed an antidepressant effect, although its mechanism is still not completely elucidated. The aim of the present study was to clarify the alteration in neuroanatomical function elicited by low-frequency TMS of the right DLPFC in treatment-resistant depression and to detect the difference between responders and nonresponders to TMS. Single-photon emission computed tomography with (99m)Tc-ethyl cysteinate dimer was performed in 14 right-handed male patients with treatment-resistant unipolar depression before and after low-frequency TMS of the right DLPFC. Five 60-second 1-Hz trains were applied and 12 treatment sessions were administered within a 3-week period (total pulses, 3,600). The Hamilton Rating Scale for Depression was administered and the regional cerebral blood flow (rCBF) was analyzed using statistical parametric mapping (SPM2). After TMS treatment in 14 patients, the score on the Hamilton Rating Scale for Depression decreased significantly, and considerable decreases in rCBF were seen in the bilateral prefrontal, orbitofrontal, anterior insula, right subgenual cingulate, and left parietal cortex, but no significant increase in rCBF occurred. Additionally, as compared with 8 nonresponders, 6 responders showed significant increases in rCBF at baseline in the left hemisphere including the prefrontal and limbic-paralimbic regions. These results suggest that the antidepressant effect of low-frequency TMS of the right DLPFC is associated with a decrease in rCBF in the limbic-paralimbic regions via the ipsilateral subgenual cingulate, and increased rCBF at baseline in the left hemisphere may be involved in the response to low-frequency TMS treatment.     

Changes in QEEG prefrontal cordance as a predictor of response to antidepressants in patients with treatment resistant depressive disorder: a pilot study

INTRODUCTION: Previous studies of patients with unipolar depression have shown that early decreases of EEG cordance (a new quantitative EEG method) can predict clinical response. We examined whether early QEEG decrease represents a phenomenon associated with response to treatment with different antidepressants in patients with treatment resistant depression. METHOD: The subjects were 17 inpatients with treatment resistant depression. EEG data and response to treatment were monitored at baseline and after 1 and 4 weeks on an antidepressant treatment. QEEG cordance was computed at three frontal electrodes in theta frequency band. The prefrontal cordance combines complementary information from absolute and relative power of EEG spectra. Recent studies have shown that cordance correlates with cortical perfusion. Depressive symptoms were assessed using Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS: All 17 patients completed the 4-week study. All five responders showed decreases in prefrontal cordance after the first week of treatment. Only 2 of the 12 nonresponders showed early prefrontal cordance decrease. The decrease of prefrontal QEEG cordance after week 1 in responders as well as the increase in nonresponders were both statistically significant (p-value 0.03 and 0.01, respectively) and the changes of prefrontal cordance values were different between both groups (p-value 0.001). CONCLUSION: Our results suggest that decrease in prefrontal cordance may indicate early changes of prefrontal activity in responders to antidepressants. QEEG cordance may become a useful tool in the prediction of response to antidepressants.     

Changes in brain function of depressed subjects during treatment with placebo.

OBJECTIVE: It has been proposed that 50%-75% of the efficacy of antidepressant medication represents the placebo effect, since many depressed patients improve when treated with either medication or placebo. This study examined brain function in depressed subjects receiving either active medication or placebo and sought to determine whether quantitative electroencephalography (QEEG) could detect differences in brain function between medication and placebo responders. Both QEEG power and cordance, a new measure that reflects cerebral perfusion and is sensitive to the effect of antidepressant medication, were examined. METHOD: Fifty-one subjects with major depression were enrolled in one of two independent, 9-week double-blind, placebo-controlled studies in which either fluoxetine (N=24) or venlafaxine (N=27) was the active medication. Serial QEEG recordings were performed during the course of treatment. After 9 weeks, the blind was broken and subjects were classified as medication responders, placebo responders, medication nonresponders, or placebo nonresponders. RESULTS: No significant pretreatment differences in clinical or QEEG measures were found among the four outcome groups. Placebo responders, however, showed a significant increase in prefrontal cordance starting early in treatment that was not seen in medication responders (who showed decreased cordance) or in medication nonresponders or placebo nonresponders (who showed no significant change). There was no significant change in QEEG power during treatment. CONCLUSIONS: These findings suggest that "effective" placebo treatment induces changes in brain function that are distinct from those associated with antidepressant medication. If these results are confirmed, cordance may be useful for differentiating between medication and placebo responders.     

Regional Brain Metabolism and Treatment Response in Panic Disorder Patients: An [F]FDG-PET Study

Background: Panic disorder (PD) is a common and often chronic psychiatric condition that can lead to considerable disability in daily life. Using [(18)F]fluorodeoxyglucose-PET, we examined brain baseline glucose metabolism in PD patients in comparison with normal controls and the changes in glucose metabolism after 12 weeks of escitalopram treatment. Methods: Fifteen patients with PD were compared to 20 normal controls using [(18)F]FDG-PET at baseline and brain metabolism after 12 weeks of escitalopram treatment was compared to pretreatment in the patient group using voxel-based statistical analysis and post hoc region-of-interest analysis. Results: Patients with PD showed decreased metabolism in both the frontal, right temporal, and left posterior cingulate gyruses. After 12 weeks of escitalopram treatment, treatment responders showed metabolic increases in global neocortical areas as well as limbic areas whereas nonresponders did not. Conclusion: Abnormal neocortical function appears to be associated with the pathophysiology of PD and escitalopram exerts its therapeutic action by modulating brain activity at the level of the neocortex and limbic system, notably the amygdala and parahippocampal gyrus.     

Differences in brain glucose metabolism between responders to CBT and venlafaxine in a 16-week randomized controlled trial

OBJECTIVE: Neuroimaging investigations reveal changes in glucose metabolism (fluorine-18-fluorodeoxyglucose positron emission tomography [PET]) associated with response to disparate antidepressant treatment modalities, including cognitive behavior therapy (CBT), antidepressant pharmacotherapies, and deep brain stimulation. Using a nonrandomized design, the authors previously compared changes following CBT or paroxetine in depressed patients. In this study, the authors report changes in fluorine-18-fluorodeoxyglucose PET in responders to CBT or venlafaxine during a randomized controlled trial. METHODS: Subjects meeting DSM-IV-TR criteria for a major depressive episode and a diagnosis of a major depressive disorder received a fluorine-18-fluorodeoxyglucose PET scan before randomization and after 16 weeks of antidepressant treatment with either CBT (N=12) or venlafaxine (N=12). Modality-specific and modality-independent regional brain metabolic changes associated with response status were analyzed. RESULTS: Response rates were comparable between the CBT (7/12) and venlafaxine (9/12) groups. Response to either treatment modality was associated with decreased glucose metabolism bilaterally in the orbitofrontal cortex and left medial prefrontal cortex, along with increased metabolism in the right occipital-temporal cortex. Changes in metabolism in the anterior and posterior parts of the subgenual cingulate cortex and the caudate differentiated CBT and venlafaxine responders. CONCLUSIONS: Responders to either treatment modality demonstrated reduced metabolism in several prefrontal regions. Consistent with earlier reports, response to CBT was associated with a reciprocal modulation of cortical-limbic connectivity, while venlafaxine engaged additional cortical and striatal regions previously unreported in neuroimaging investigations.     

Modulation of cortical-limbic pathways in major depression: treatment-specific effects of cognitive behavior therapy

BACKGROUND: Functional imaging studies of major depressive disorder demonstrate response-specific regional changes following various modes of antidepressant treatment. OBJECTIVE: To examine changes associated with cognitive behavior therapy (CBT). METHODS: Brain changes underlying response to CBT were examined using resting-state fluorine-18-labeled deoxyglucose positron emission tomography. Seventeen unmedicated, unipolar depressed outpatients (mean +/- SD age, 41 +/- 9 years; mean +/- SD initial 17-item Hamilton Depression Rating Scale score, 20 +/- 3) were scanned before and after a 15- to 20-session course of outpatient CBT. Whole-brain, voxel-based methods were used to assess response-specific CBT effects. A post hoc comparison to an independent group of 13 paroxetine-treated responders was also performed to interpret the specificity of identified CBT effects. RESULTS: A full course of CBT resulted in significant clinical improvement in the 14 study completers (mean +/- SD posttreatment Hamilton Depression Rating Scale score of 6.7 +/- 4). Treatment response was associated with significant metabolic changes: increases in hippocampus and dorsal cingulate (Brodmann area [BA] 24) and decreases in dorsal (BA 9/46), ventral (BA 47/11), and medial (BA 9/10/11) frontal cortex. This pattern is distinct from that seen with paroxetine-facilitated clinical recovery where prefrontal increases and hippocampal and subgenual cingulate decreases were seen. CONCLUSIONS: Like other antidepressant treatments, CBT seems to affect clinical recovery by modulating the functioning of specific sites in limbic and cortical regions. Unique directional changes in frontal cortex, cingulate, and hippocampus with CBT relative to paroxetine may reflect modality-specific effects with implications for understanding mechanisms underlying different treatment strategies.     

Neural and genetic correlates of antidepressant response to sleep deprivation: a functional magnetic resonance imaging study of moral valence decision in bipolar depression

CONTEXT: Total sleep deprivation combined with light therapy causes rapid amelioration of bipolar depression. A polymorphism in the promoter for the serotonin transporter influences both antidepressant response and the structure and function of specific brain areas. OBJECTIVE: To determine whether antidepressant therapy or the genotype of the serotonin transporter influence the pattern of neural response to a task targeting the depressive biases in information processing (moral valence decision). DESIGN: Before-and-after trial studying the biologic correlates of response to treatment. SETTING: University hospital. Patients Twenty inpatients with bipolar depression. Intervention Repeated total sleep deprivation combined with light therapy for 1 week. MAIN OUTCOME MEASURES: Brain blood oxygen level-dependent functional magnetic resonance imaging using a 3.0-T scanner before and after treatment. Self-ratings and observer ratings of mood (visual analog scale 3 times daily and Hamilton Depression Rating Scale) before and after treatment. RESULTS: We found significant interactions of treatment (before and after), response to treatment (Hamilton Depression Rating Scale score <8), and moral valence of the stimuli (positive or negative) in the anterior cingulate cortex, dorsolateral prefrontal cortex, insula, and parietal cortex. In these areas, responders changed their blood oxygen level-dependent responses to emotional stimuli in a pattern opposite of that in nonresponders. Genotype of the promoter for the serotonin transporter predicted response to treatment and influenced baseline neural responses in the anterior cingulate cortex and the dorsolateral prefrontal cortex. CONCLUSION: Multiple factors that affect or are affected at the individual level by major depressive episodes in the course of bipolar disorder significantly interact in influencing brain cortical activity in specific areas.     

Treatment of pediatric anxiety disorders: an open-label extension of the research units on pediatric psychopharmacology anxiety study

BACKGROUND: An 8-week placebo-controlled study, the Research Units on Pediatric Psychopharmacology Anxiety Study, documented beneficial effects of fluvoxamine in the treatment of pediatric social anxiety, separation anxiety, or generalized anxiety disorders. Following completion of this study, participants were invited to enter a 6-month open-label treatment phase designed to examine three issues: (a) long-term maintenance of response in fluvoxamine responders, (b) acute response to fluoxetine in fluvoxamine nonresponders, and (c) acute response to fluvoxamine in placebo nonresponders. METHODS: Participants aged 6-17 years meeting criteria for social anxiety, separation anxiety, or generalized anxiety disorders previously treated in an 8-week placebo-controlled trial (n = 128) were offered open treatment. Changes in symptoms of anxiety during open treatment were assessed in three groups: (a) fluvoxamine responders maintained on fluvoxamine, (b) fluvoxamine nonresponders changed to fluoxetine, and (c) placebo nonresponders changed to fluvoxamine. Response was defined based on Clinical Global Impression criteria. RESULTS: During 6 months of continued open treatment, anxiety symptoms remained low in 33 of 35 (94%) subjects who initially responded to fluvoxamine. Among 14 fluvoxamine nonresponders switched to fluoxetine, anxiety symptoms appeared significantly improved in 10 (71%) subjects. Finally, among 48 placebo nonresponders, 27 (56%) showed clinically significant improvement in anxiety on fluvoxamine. CONCLUSION: The current findings concerning extended treatment of pediatric anxiety disorders are only preliminary, because treatment was uncontrolled. Results suggest that an initial fluvoxamine response is likely to be retained with continued treatment, that some fluvoxamine nonresponders may respond to fluoxetine, and that some placebo nonresponders may respond to fluvoxamine.     

Attenuation of the neural response to sad faces in major depression by antidepressant treatment: a prospective, event-related functional magnetic resonance imaging study

BACKGROUND: Depression is associated with interpersonal difficulties related to abnormalities in affective facial processing. OBJECTIVES: To map brain systems activated by sad facial affect processing in patients with depression and to identify brain functional correlates of antidepressant treatment and symptomatic response. DESIGN: Two groups underwent scanning twice using functional magnetic resonance imaging (fMRI) during an 8-week period. The event-related fMRI paradigm entailed incidental affect recognition of facial stimuli morphed to express discriminable intensities of sadness. SETTING: Participants were recruited by advertisement from the local population; depressed subjects were treated as outpatients. PATIENTS AND OTHER PARTICIPANTS: We matched 19 medication-free, acutely symptomatic patients satisfying DSM-IV criteria for unipolar major depressive disorder by age, sex, and IQ with 19 healthy volunteers.Intervention After the baseline assessment, patients received fluoxetine hydrochloride, 20 mg/d, for 8 weeks. MAIN OUTCOME MEASURES: Average activation (capacity) and differential response to variable affective intensity (dynamic range) were estimated in each fMRI time series. We used analysis of variance to identify brain regions that demonstrated a main effect of group (depressed vs healthy subjects) and a group x time interaction (attributable to antidepressant treatment). Change in brain activation associated with reduction of depressive symptoms in the patient group was identified by means of regression analysis. Permutation tests were used for inference. RESULTS: Over time, depressed subjects showed reduced capacity for activation in the left amygdala, ventral striatum, and frontoparietal cortex and a negatively correlated increase of dynamic range in the prefrontal cortex. Symptomatic improvement was associated with reduction of dynamic range in the pregenual cingulate cortex, ventral striatum, and cerebellum. CONCLUSIONS: Antidepressant treatment reduces left limbic, subcortical, and neocortical capacity for activation in depressed subjects and increases the dynamic range of the left prefrontal cortex. Changes in anterior cingulate function associated with symptomatic improvement indicate that fMRI may be a useful surrogate marker of antidepressant treatment response.     

Reciprocal limbic-cortical function and negative mood: converging PET findings in depression and normal sadness.

OBJECTIVE: Theories of human behavior from Plato to Freud have repeatedly emphasized links between emotion and reason, a relationship now commonly attributed to pathways connecting phylogenetically "old" and "new" brain regions. Expanding on this theory, this study examined functional interactions between specific limbic and neocortical regions accompanying normal and disease-associated shifts in negative mood state. METHOD: Regions of concordant functional change accompanying provocation of transient sadness in healthy volunteers and resolution of chronic dysphoric symptoms in depressed patients were examined with two positron emission tomography techniques: [15O]water and [18F]fluorodeoxyglucose, respectively. RESULTS: With sadness, increases in limbic-paralimbic blood flow (subgenual cingulate, anterior insula) and decreases in neocortical regions (right dorsolateral prefrontal, inferior parietal) were identified. With recovery from depression, the reverse pattern, involving the same regions, was seen--limbic metabolic decreases and neocortical increases. A significant inverse correlation between subgenual cingulate and right dorsolateral prefrontal activity was also demonstrated in both conditions. CONCLUSIONS: Reciprocal changes involving subgenual cingulate and right prefrontal cortex occur with both transient and chronic changes in negative mood. The presence and maintenance of functional reciprocity between these regions with shifts in mood in either direction suggests that these regional interactions are obligatory and probably mediate the well-recognized relationships between mood and attention seen in both normal and pathological conditions. The bidirectional nature of this limbic-cortical reciprocity provides additional evidence of potential mechanisms mediating cognitive ("top-down"), pharmacological (mixed), and surgical ("bottom-up") treatments of mood disorders such as depression.     

Neuroanatomical correlates of therapeutic efficacy of low-frequency right prefrontal transcranial magnetic stimulation in treatment-resistant depression

Aims: Low‐frequency transcranial magnetic stimulation (TMS) to the right prefrontal cortex has been shown to be effective in treatment‐resistant depression. The aim of the present study was to investigate changes in regional cerebral blood flow (rCBF) after low‐frequency right prefrontal stimulation (LFRS), and neuroanatomical correlates of therapeutic efficacy of LFRS in treatment‐resistant depression. Methods: Twenty‐six patients with treatment‐resistant depression received five 60‐s 1‐Hz trains over the right prefrontal cortex, and 12 treatment sessions were administered during 3 weeks. Brain scans were acquired before and after LFRS using single photon emission computed tomography with ^99mTc‐ethyl cysteinate dimer. Severity of depression was assessed on the Hamilton Depression Rating Scale (HDRS). Results: Significant decreases in rCBF after LFRS were seen in the prefrontal cortex, orbitofrontal cortex, subgenual cingulate cortex, globus pallidus, thalamus, anterior and posterior insula, and midbrain in the right hemisphere. Therapeutic efficacy of LFRS was correlated with decreases in rCBF in the right prefrontal cortex, bilateral orbitofrontal cortex, right subgenual cingulate cortex, right putamen, and right anterior insula. Conclusion: The antidepressant effects of LFRS in treatment‐resistant depression may be associated with decreases in rCBF in the orbitofrontal cortex and the subgenual cingulate cortex via the right prefrontal cortex.     

Brain imaging correlates of depressive symptom severity and predictors of symptom improvement after antidepressant treatment.

BACKGROUND: It would be therapeutically useful to predict clinical response to antidepressant drugs. We evaluated structural magnetic resonance imaging (MRI) and functional MRI (fMRI) data as predictors of symptom change in people with depression. METHODS: Brain structure and function were measured with MRI in 17 patients with major depression immediately before 8 weeks treatment with fluoxetine 20 mg/day. For fMRI, patients were scanned during visual presentation of faces representing different intensities of sadness. Clinical response was measured by change in serial scores on the Hamilton Rating Scale for Depression. Symptom change scores (and baseline symptom severity) were regressed on structural and functional MRI data to map brain regions where grey matter volume, or activation by sad facial affect processing, was significantly associated with symptom change (or baseline severity). RESULTS: Faster rates of symptom improvement were strongly associated with greater grey matter volume in anterior cingulate cortex, insula, and right temporo-parietal cortex. Patients with greater than median grey matter volume in this system had faster rates of improvement and significantly lower residual symptom scores after 8 weeks' treatment. Faster improvement was also predicted by greater functional activation of anterior cingulate cortex. Baseline symptom severity was negatively correlated with greater grey matter volume in dorsal prefrontal and anterior midcingulate regions anatomically distinct from the pregenual and subgenual cingulate regions predicting treatment response. CONCLUSIONS: Structural MRI measurements of anterior cingulate cortex could provide a useful predictor of antidepressant treatment response.     

Supraphysiological doses of levothyroxine alter regional cerebral metabolism and improve mood in bipolar depression

Supplementation of standard treatment with high-dose levothyroxine (L-T(4)) is a novel approach for treatment-refractory bipolar disorders. This study tested for effects on brain function associated with mood alterations in bipolar depressed patients receiving high-dose L-T(4) treatment adjunctive to ongoing medication (antidepressants and mood stabilizers). Regional activity and whole-brain analyses were assessed with positron emission tomography and [(18)F]fluorodeoxyglucose in 10 euthyroid depressed women with bipolar disorder, before and after 7 weeks of open-label adjunctive treatment with supraphysiological doses of L-T(4) (mean dose 320 microg/day). Corresponding measurements were acquired in an age-matched comparison group of 10 healthy women without L-T(4) treatment. The primary biological measures were relative regional activity (with relative brain radioactivity taken as a surrogate index of glucose metabolism) in preselected brain regions and neuroendocrine markers of thyroid function. Treatment-associated changes in regional activity (relative to global activity) were tested against clinical response. Before L-T(4) treatment, the patients exhibited significantly higher activity in the right subgenual cingulate cortex, left thalamus, medial temporal lobe (right amygdala, right hippocampus), right ventral striatum, and cerebellar vermis; and had lower relative activity in the middle frontal gyri bilaterally. Significant behavioral and cerebral metabolic effects accompanied changes in thyroid hormone status. L-T(4) improved mood (remission in seven patients; partial response in three); and decreased relative activity in the right subgenual cingulate cortex, left thalamus, right amygdala, right hippocampus, right dorsal and ventral striatum, and cerebellar vermis. The decrease in relative activity of the left thalamus, left amygdala, left hippocampus, and left ventral striatum was significantly correlated with reduction in depression scores. Results of the whole-brain analyses were generally consistent with the volume of interest results. We conclude that bipolar depressed patients have abnormal function in prefrontal and limbic brain areas. L-T(4) may improve mood by affecting circuits involving these areas, which have been previously implicated in affective disorders.     

Symptom clusters as predictors of late response to antidepressant treatment

OBJECTIVE: While there is some indication from studies in the acute phase of antidepressant treatment that there are differences in the timing of improvement in symptoms, relatively little work has explored the patterns of change for specific symptom clusters and the predictability of these changes to signal eventual response during the acute phase of treatment. This article investigates the use of clusters of symptoms on the 17-item Hamilton Rating Scale for Depression (HAM-D-17) to define the pattern of late response versus nonresponse to antidepressant medication. METHOD: Using principal component analysis, the HAM-D-17 was divided into 4 symptom clusters (mood, sleep/psychic anxiety, appetite, and somatic anxiety/weight). Data for 996 patients with major depressive disorder (DSM-III-R criteria), who participated in a 12-week acute phase study with nefazodone, were subjected to a post hoc analysis of changes in symptom cluster scores. Patients were divided into 3 groups: early responders (< 4 weeks), late responders (4-12 weeks), and nonresponders (> 12 weeks) as defined by < 50% reduction in HAM-D-17 scores from baseline. The late-responder and nonresponder groups were subjected to the principal component analysis. Data were collected from October 1992 to November 1994. RESULTS: There were significant differences in the pattern of symptom change on the mood cluster (weeks 3-4) (p < .0001), the sleep/psychic anxiety cluster (weeks 3-4) (p < .003), and the somatic anxiety/weight cluster (weeks 3-4) (p < .01) for the late responders compared to the nonresponders. Using change scores, a discriminant function analysis correctly assigned 127 of the 182 late responders and 85 of the 133 nonresponders, or 70% of the late responders and 64% of the nonresponders, to their final response groups. CONCLUSION: Monitoring changes in symptom clusters from the HAM-D-17 during this crucial early stage (first 4 weeks) can be used to distinguish late responders (after week 4) from nonresponders. Successful identification of nonresponders based on symptom cluster change in the first 4 weeks would facilitate a shortening of an ineffective treatment trial and allow for necessary changes in treatment strategy, helping physicians more closely follow treatment guidelines.     

Effect of sleep deprivation on brain metabolism of depressed patients.

OBJECTIVE: Sleep deprivation is a rapid, nonpharmacologic antidepressant intervention that is effective for a subset of depressed patients. The objective of this study was to identify which brain structures' activity differentiates responders from nonresponders and to study how metabolism in these brain regions changes with mood. METHOD: Regional cerebral glucose metabolism was assessed by positron emission tomography (PET) with [18F]deoxyglucose (FDG) before and after total sleep deprivation in 15 unmedicated awake patients with unipolar major depression and 15 normal control subjects, who did the continuous performance test during FDG uptake. RESULTS: After sleep deprivation, four patients showed a 40% or more improvement on the Hamilton Rating Scale for Depression. Before sleep deprivation the depressed responders had a significantly higher cingulate cortex metabolic rate than the depressed nonresponders, and this normalized after sleep deprivation. The normal control subjects and nonresponding depressed patients showed no change in cingulate metabolic rate after sleep deprivation. CONCLUSIONS: Overactivation of the limbic system as assessed by PET scans may characterize a subset of depressed patients. Normalization of activity with sleep deprivation is associated with a decrease in depression.     

Neurometabolite effects of response to quetiapine and placebo in adolescents with bipolar depression

Abstract Objective: Mood stabilizers have been reported to affect brain concentrations of myo-inositol (mI) and N-acetylaspartate (NAA). We examined the effects of quetiapine (QUET), an atypical antipsychotic, on these neurochemicals, and potential predictors of response to QUET in adolescents with bipolar depression. Methods: Twenty-six adolescents with bipolar depression participated in an 8-week placebo-controlled trial of QUET monotherapy. Subjects were scanned at baseline and after 8 weeks with proton magnetic resonance spectroscopy (1H-MRS) at 3T and 4T at two sites, with 8?cm(3) voxels placed in the right and left dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC). LCModel was used to calculate absolute concentrations of NAA and mI. Results: Twenty-six subjects had pre- and posttreatment scans (mean age=15.6 years, 9 boys). Of these subjects, 5 out of 16 subjects receiving QUET and 5 out of 10 receiving placebo (PBO) were responders (50% decrease in Children's Depression Rating Scale [CDRS] score). Although baseline ACC mI did not predict responder status, responders had significantly lower posttreatment ACC mI values than did nonresponders (3.27±.71 vs. 4.23±.70; p=0.004). There were no significant differences in the changes in ACC and DLPFC NAA levels in the QUET group compared with the PBO group (ACC: -0.55±1.3 vs.+0.25±1.5, p=0.23; right-DLPFC: -0.55±1.3 vs. 0.33±0.89, p=0.13; left-DLPFC: -0.04±0.91 vs.+0.29±0.61, p=0.41). Conclusion: We found that posttreatment, not baseline, ACC mI levels were associated with response to QUET in adolescents with bipolar depression. There were no differences in NAA concentration changes between the QUET and PBO groups. Larger studies including different brain regions would help to clarify the effects of QUET on neurochemistry in patients with bipolar disorder.     

Baseline cerebral hypermetabolism associated with carbamazepine response, and hypometabolism with nimodipine response in mood disorders.

BACKGROUND: Positron emission tomography (PET) studies have reported baseline (medication free) differences between mood disorder patients and healthy control subjects, but relatively little is known about relationships between baseline PET scans and treatment responses. Carbamazepine (CBZ) and to a more limited extent nimodipine (NIMO) seem useful in mood disorders. We explored whether baseline regional cerebral glucose metabolism (rCMRglu) could discriminate CBZ and NIMO responders from nonresponders and healthy control subjects. METHODS: In refractory mood disorder patients, we examined relationships between responses to these drugs, assessed by Clinical Global Impression-Improvement scores, and baseline rCMRglu, determined with fluorine-18 deoxy-glucose and PET. RESULTS: CBZ responders had baseline left insular hyper-metabolism compared to healthy control subjects and nonresponders, whereas nonresponders had widespread (including left insular) hypometabolism. Degree of CBZ response correlated with baseline paralimbic (including insula) and prefrontal hypermetabolism. In responders but not nonresponders, CBZ decreased widespread metabolism, with the degree of decrease in left insula correlating with response. In contrast, NIMO responders but not nonresponders had baseline widespread (including left insular) hypometabolism. Left prefrontal and left insular baseline hypometabolism, but not metabolic changes with treatment correlated with degree of NIMO response. CONCLUSIONS: These data suggest that baseline anterior paralimbic and prefrontal hypermetabolism may be associated with CBZ response, and hypometabolism with NIMO response. Based on these preliminary data, further exploration of relationships between baseline PET scans and treatment responses is indicated.     

A double-blind, placebo-controlled trial of olanzapine addition in fluoxetine-refractory obsessive-compulsive disorder.

BACKGROUND: One of the few combination approaches to the treatment of obsessive-compulsive disorder (OCD) with encouraging support is the addition of an antipsychotic to a serotonin reuptake inhibitor. METHODS: The study consisted of a 6-week, placebo-controlled addition of olanzapine 5-10 mg (6.1 +/- 2.1 mg, mean +/- SD) to fluoxetine in OCD subjects who were partial or nonresponders to an 8-week, open-label fluoxetine trial (40 mg in 43 subjects, 20 mg in 1 subject). RESULTS: Both the fluoxetine-plus-olanzapine (n = 22) and fluoxetine-plus-placebo (n = 22) groups improved significantly over 6 weeks [F(3,113) = 11.64, p <.0001] according to Yale-Brown Obsessive Compulsive Scale scores with repeated-measures analysis of variance; however, the treatment x time interaction was not significant for olanzapine versus placebo addition to fluoxetine. CONCLUSIONS: These findings indicate no additional advantage of adding olanzapine for 6 weeks in OCD patients who have not had a satisfactory response to fluoxetine for 8 weeks, compared with extending the monotherapy trial.     

Changes in prefrontal activity characterize clinical response in SSRI nonresponders: a pilot study

Previous studies in unipolar depression have shown that early decreases in prefrontal values of the QEEG cordance measure identified responders to pharmacotherapy. These studies have all examined individuals who were drug-free prior to the first physiologic assessment, yet in the clinical management of treatment resistant depression (TRD), many patients undergo changes in treatment without a drug-free interval between treatments. Here, we investigated whether cordance decreases were associated with response in Stage I TRD subjects without wash-out between treatment trials. Awake EEGs were recorded from 12 adults with unipolar depression. Subjects were receiving naturalistic treatment, had failed SSRI monotherapy, and were starting a new treatment prescribed by their treating psychiatrists. EEG data were recorded before starting the new treatment and after approximately 1 week. Six of the 12 subjects responded to treatment after 8--10 weeks. Five of the six responders showed an early cordance decreases, compared with two of the six nonresponders (accurate characterization in 75% of the cases). Consistent with previous treatment trials, decreases in prefrontal cordance differentiated responders from nonresponders in this setting as well. These findings suggest that cordance biomarkers may be a useful tool in effectiveness trials that parallel clinical practices in SSRI nonresponders, and may not require a wash-out period between treatments.