Low-frequency repetitive transcranial magnetic stimulation to the temporoparietal junction for tinnitus: four-week stimulation trial.

IMPORTANCE: This research examines the impact of 4 weeks of repetitive transcranial magnetic stimulation (rTMS) stimulation to the temporoparietal junction and compares the results of this longer duration of treatment with a similar stimulus protocol of only 2 weeks' duration. OBJECTIVE: To examine the effectiveness and safety of 4 weeks of low-frequency rTMS to the left temporoparietal junction in a cohort of patients with bothersome tinnitus. DESIGN: Crossover, double-blind, randomized controlled trial. SETTING: Outpatient academic medical center. PARTICIPANTS: The study population comprised 14 adults aged between 22 and 59 years with subjective, unilateral or bilateral, nonpulsatile tinnitus of 6 months' duration or greater and a score of 34 or greater on the Tinnitus Handicap Inventory (THI). INTERVENTIONS: Low-frequency (1 Hz) 110% motor threshold rTMS or sham to the left temporoparietal junction for 4 weeks. MAIN OUTCOME AND MEASURE: The difference of the change in the THI score between active rTMS and sham rTMS. RESULTS: Active treatment was associated with a median reduction in THI score of 10 (range, -20 to +4) points, and sham treatment was associated with a median reduction of 6 (range, -24 to +12) points. The median difference in THI score between the change associated with active and sham rTMS was 4 (95% CI, -9 to 10; and range, -32 to +14) points. CONCLUSIONS AND RELEVANCE: Daily low-frequency active rTMS to the left temporoparietal junction area for 4 weeks was no more effective than sham for patients with chronic bothersome tinnitus. Possible explanations for this negative study include the failure of rTMS to stimulate deeper parts of auditory cortex within the sylvian fissure and more widespread cortical network changes not amenable to localized rTMS effects. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00567892.

Neural correlates of weight gain with olanzapine.

CONTEXT Iatrogenic obesity caused by atypical antipsychotics increases the rate of death from all causes. Olanzapine is a commonly prescribed atypical antipsychotic medication that frequently causes weight gain. To our knowledge, the neural correlates of this weight gain have not been adequately studied in humans. OBJECTIVE To test the hypothesis that olanzapine treatment disrupts the neural activity associated with the anticipation and receipt (consumption) of food rewards (chocolate milk and tomato juice). DESIGN Event-related functional magnetic resonance imaging study, before and after a 1-week treatment with olanzapine. SETTING A university neuroimaging center. PARTICIPANTS Twenty-five healthy individuals. MAIN OUTCOME MEASURES Changes in blood oxygen level-dependent activations to the anticipation and receipt of food rewards after olanzapine treatment. RESULTS One week of olanzapine treatment caused significant increases in weight, food consumption, and disinhibited eating. Our imaging data showed enhanced activations in the inferior frontal cortex, striatum, and anterior cingulate cortex to the anticipation of a food reward. Activation in the caudate and putamen were enhanced to the receipt of the rewarding food. We also found a decrease in reward responsivity to receipt of the rewarding food in the lateral orbital frontal cortex, an area of the brain thought to exercise inhibitory control on feeding. CONCLUSIONS Olanzapine treatment enhanced both the anticipatory and consummatory reward responses to food rewards in the brain reward circuitry that is known to respond to food rewards in healthy individuals. We also noted a decrease in responsivity to food consumption in a brain area thought to inhibit feeding behavior.

Late life depression with cognitive impairment: evaluation and treatment.

Older adults with depression often present with signs and symptoms indicative of functional or cognitive impairment. These somatic symptoms make evaluating and treating depression in older adults more complex. Late life depression (LLD), depression in adults over the age of 65, is more frequently associated with cognitive changes. Cognitive impairment in LLD may be a result of the depressive disorder or an underlying dementing condition. Memory complaints are also common in older adults with depression. There is a wide range of cognitive impairment in LLD including decreased central processing speed, executive dysfunction, and impaired short-term memory. The etiology of cognitive impairment in LLD may include cerebrovascular disease, a significant risk factor for LLD, which likely interrupts key pathways between frontal white matter and subcortical structures important in mood regulation. Because depressive symptoms often coexist with dementia, it is important to determine the temporal relationship between depressive symptoms and cognitive change. If depressive symptoms pre-date the cognitive impairment and cognitive symptoms are mild and temporary, LLD is the likely etiology of the cognitive impairment. If cognitive changes appear prior to depressive symptoms and persist after LLD is successfully treated, an underlying dementia is more likely. Clinicians should be exclude common conditions such as thyroid disease which can contribute to depressive symptoms and cognitive impairment prior to treating LLD. Both antidepressants and psychotherapy can be effective in treating LLD. Subsequent evaluations following treatment should also reassess cognition.

Antidepressant treatment normalizes hypoactivity in dorsolateral prefrontal cortex during emotional interference processing in major depression.

BACKGROUND: Major depression (MDD) is characterized by altered emotion processing and deficits in cognitive control. In cognitive interference tasks, patients with MDD have shown excessive amygdala activity and under-recruitment of dorsolateral prefrontal cortex (DLPFC). The purpose of this study was to examine the effects of antidepressant treatment on anomalous neural activity in cognitive-control and emotion-processing circuitry. METHODS: Functional magnetic resonance imaging was conducted on depressed patients (n=23) (both before and after antidepressant treatment) compared with matched controls (n=18) while they performed a cognitive task involving attended and unattended fear-related stimuli. RESULTS: After eight weeks of SSRI antidepressant treatment, patients with depression showed significantly increased DLPFC activity to unattended fear-related stimuli and no longer differed from controls in either DLPFC or amygdala activity. CONCLUSIONS: These results suggest that antidepressant treatment increases DLPFC under-activity during cognitive tasks that include emotional interference. LIMITATIONS: The sample was fairly homogeneous and this may limit generalizability.

Altered emotional interference processing in affective and cognitive-control brain circuitry in major depression.

BACKGROUND: Major depression is characterized by a negativity bias: an enhanced responsiveness to, and memory for, affectively negative stimuli. However, it is not yet clear whether this bias represents 1) impaired top-down cognitive control over affective responses, potentially linked to deficits in dorsolateral prefrontal cortex function; or 2) enhanced bottom-up responses to affectively laden stimuli that dysregulate cognitive control mechanisms, potentially linked to deficits in amygdala and anterior cingulate function. METHODS: We used an attentional interference task using emotional distracters to test for top-down versus bottom-up dysfunction in the interaction of cognitive-control circuitry and emotion-processing circuitry. A total of 27 patients with major depression and 24 control participants was tested. Event-related functional magnetic resonance imaging was carried out as participants directly attended to, or attempted to ignore, fear-related stimuli. RESULTS: Compared with control subjects, patients with depression showed an enhanced amygdala response to unattended fear-related stimuli (relative to unattended neutral). By contrast, control participants showed increased activity in right dorsolateral prefrontal cortex (Brodmann areas 46/9) when ignoring fear stimuli (relative to neutral), which the patients with depression did not show. In addition, the depressed participants failed to show evidence of error-related cognitive adjustments (increased activity in bilateral dorsolateral prefrontal cortex on posterror trials), but the control group did show them. CONCLUSIONS: These results suggest multiple sources of dysregulation in emotional and cognitive control circuitry in depression, implicating both top-down and bottom-up dysfunction.

Antidepressant efficacy of olanzapine as monotherapy in major depressive disorder, without psychosis: a pilot study.

In this pilot study we assessed the efficacy of olanzapine as monotherapy in the treatment of major depressive disorder, without psychosis. We also demonstrated the in vivo 5-HT2A receptor occupancy of olanzapine using positron emission tomography. An open-label prospective 6-week study design with 14 patients who met the inclusion and exclusion criteria for the study were enrolled from the general community of the St. Louis metropolitan area. All patients met DSM-IV criteria for major depressive disorder without psychosis, had a Hamilton Depression Rating Scale (HAMD17) score >18 and were between the ages of 18 and 65. The primary measure of efficacy was the change in HAMD 17 total score from baseline to endpoint. The data were collected between 1998 and 2004. There was a significant reduction in the HAMD17 scores from baseline to endpoint. Half the patients (n=6) showed > or =50% reduction in their HAMD17 scores. This study points to the potential of olanzapine as a therapeutic agent for the treatment of major depressive disorder without psychosis.

3beta -hydroxypregnane steroids are pregnenolone sulfate-like GABA(A) receptor antagonists.

Endogenous neurosteroids have rapid actions on ion channels, particularly GABA(A) receptors, which are potentiated by nanomolar concentrations of 3alpha-hydroxypregnane neurosteroids. Previous evidence suggests that 3beta-hydroxypregnane steroids may competitively antagonize potentiation induced by their 3alpha diastereomers. Because of the potential importance of antagonists as experimental and clinical tools, we characterized the functional effect of 3beta-hydroxysteroids. Although 3beta-hydroxysteroids reduced the potentiation induced by 3alpha-hydroxysteroids, 3beta-hydroxysteroids acted noncompetitively with respect to potentiating steroids and inhibited the largest degrees of potentiation most effectively. Potentiation by high concentrations of barbiturates was also reduced by 3beta-hydroxysteroids. 3beta-Hydroxysteroids are also direct, noncompetitive GABA(A) receptor antagonists. 3beta-Hydroxysteroids coapplied with GABA significantly inhibited responses to > or =15 microm GABA. The profile of block was similar to that exhibited by sulfated steroids, known blockers of GABA(A) receptors. This direct, noncompetitive effect of 3beta-hydroxysteroids was sufficient to account for the apparent antagonism of potentiating steroids. Mutated receptors exhibiting decreased sensitivity to sulfated steroid block were insensitive to both the direct effects of 3beta-hydroxysteroids on GABA(A) responses and the reduction of potentiating steroid effects. At concentrations that had little effect on GABAergic synaptic currents, 3beta-hydroxysteroids and low concentrations of sulfated steroids significantly reversed the potentiation of synaptic currents induced by 3alpha-hydroxysteroids. We conclude that 3beta-hydroxypregnane steroids are not direct antagonists of potentiating steroids but rather are noncompetitive, likely state-dependent, blockers of GABA(A) receptors. Nevertheless, these steroids may be useful functional blockers of potentiating steroids when used at concentrations that do not affect baseline neurotransmission.