Modafinil Decreased Thalamic Activation in Auditory Emotional Processing: A Randomized Controlled Functional Magnetic Resonance Imaging Study.

BACKGROUND: Modafinil improves wakefulness and attention, is approved in Japan for treatment of narcolepsy, and was reported to be effective for attention-deficit/hyperactivity disorder. However, it was reported to induce emotional instability, including mania, depression, and suicidal ideation. Such side effects may be related to changes in cognitive behavior caused by the effects of modafinil on emotional recognition. However, the effects of modafinil on the neural basis of emotional processing have not been fully verified. We used functional magnetic resonance imaging to investigate the effects of modafinil on the neural basis of auditory emotional processing. METHODS: This study adopted a placebo-controlled within-subject crossover design. Data from 14 participants were analyzed. The effects of modafinil on cerebral activation and task performance during an emotional judgement task were analyzed. RESULTS: Task accuracy decreased significantly and response time of emotional judgement was significantly delayed by modafinil, as compared with placebo. Right thalamic activation in auditory emotional processing was significantly less in the modafinil condition than in the placebo condition. In addition, reduction of right thalamic activation by modafinil was positively correlated with accuracy of emotional judgement. CONCLUSIONS: Our findings suggest that modafinil acts on the right thalamus and changes behavior and brain function associated with auditory emotional processing. These results indicate that modafinil might change emotional recognition by reducing emotional activation related to social communication.

Occupancy of serotonin transporter by tramadol: a positron emission tomography study with [11C]DASB.

Tramadol is used for the treatment of pain, and it is generally believed to activate the µ-opioid receptor and inhibit serotonin (5-HT) and norepinephrine (NE) transporters. Recent findings from animal experiments suggest that 5-HT reuptake inhibition in brain is related to pain reduction. However, there has been no report of 5-HT transporter (5-HTT) occupancy by tramadol at clinical doses in humans. In the present study, we investigated 5-HTT occupancy by tramadol in five subjects receiving various doses of tramadol by using positron emission tomography (PET) scanning with the radioligand [11C]DASB. Our data showed that mean 5-HTT occupancies in the thalamus by single doses of tramadol were 34.7% at 50 mg and 50.2% at 100 mg. The estimated median effective dose (ED50) of tramadol was 98.1 mg, and the plasma concentration was 0.33 µg/ml 2 h after its administration; 5-HTT occupancy by tramadol was dose-dependent. We estimated 5-HTT occupancy at 78.7% upon taking an upper limit dose (400 mg) of tramadol. The results of the present study support the finding that 5-HTT inhibition is involved in the mechanism underlying the analgesic effect of tramadol in humans, and a clinical dose of tramadol sufficiently inhibits 5-HTT reuptake; this inhibition is similar to that shown by selective serotonin reuptake inhibitors (SSRIs).

Norepinephrine transporter occupancy by nortriptyline in patients with depression: a positron emission tomography study with (S,S)-[¹8F]FMeNER-D2.

Norepinephrine transporter (NET) plays important roles in the treatment of various neuropsychiatric disorders, such as depression and attention deficit hyperactivity disorder (ADHD). Nortriptyline is a NET-selective tricyclic antidepressant (TCAs) that has been widely used for the treatment of depression. Previous positron emission tomography (PET) studies have reported over 80% serotonin transporter occupancy with clinical doses of selective serotonin reuptake inhibitors (SSRIs), but there has been no report of NET occupancy in patients treated with relatively NET-selective antidepressants. In the present study, we used PET and (S,S)-[18¹8F]FMeNER-D2 to investigate NET occupancies in the thalamus in 10 patients with major depressive disorder taking various doses of nortriptyline, who were considered to be responders to the treatment. Reference data for the calculation of occupancy were derived from age-matched healthy controls. The result showed approximately 50-70% NET occupancies in the brain as a result of the administration of 75-200 mg/d of nortriptyline. The estimated effective dose (ED50) and concentration (EC50) required to induce 50% occupancy was 65.9 mg/d and 79.8 ng/ml, respectively. Furthermore, as the minimum therapeutic level of plasma nortriptyline for the treatment of depression has been reported to be 70 ng/ml, our data indicate that this plasma nortriptyline concentration corresponds to approximately 50% NET occupancy measured with PET, suggesting that more than 50% of central NET occupancy would be appropriate for the nortriptyline treatment of patients with depression.

Efficacy and tolerability of risperidone, yokukansan, and fluvoxamine for the treatment of behavioral and psychological symptoms of dementia: a blinded, randomized trial.

The descriptive term behavioral and psychological symptoms of dementia (BPSD) is used to cover a range of noncognitive disturbances including anxiety, depression, irritability, aggression, agitation, eating disorders, and inappropriate social or sexual behaviors. Behavioral and psychological symptoms of dementia are seen in about 90% of patients with dementia. We aimed to compare the efficacy and tolerability of risperidone, yokukansan, and fluvoxamine used for BPSD in elderly patients with dementia. Ninety inpatients with dementia according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria were investigated in Sato Hospital, Koutokukai. We conducted an 8-week, rater-blinded, randomized trial, administering flexibly dosed risperidone, yokukansan, or fluvoxamine. Primary outcome measures were Neuropsychiatric Inventory in Nursing Home Version total score and its items. Secondary outcome measures were cognitive function measured by Mini-Mental State Examination and daily life function measured by Functional Independence Measure (FIM). Neurological adverse effects were measured by the Drug-Induced Extra-Pyramidal Symptoms Scale. At the end of the study, we analyzed 76 patients (92.7%). Mean Neuropsychiatric Inventory in Nursing Home Version total score decreased in all 3 drug groups, with no significant between-group differences. Mini-Mental State Examination and Functional Independence Measure scores did not change significantly. Drug-Induced Extra-Pyramidal Symptoms Scale scores did not change in the yokukansan and fluvoxamine groups, but increased significantly in the risperidone group. Risperidone, yokukansan, and fluvoxamine were equally effective in the treatment of BPSD in elderly patients. However, yokukansan or fluvoxamine for BPSD showed a more favorable profile in tolerability compared with risperidone. This trial is registered at UMIN Clinical Trials Registry (identifier: UMIN000006146).

Repetitive transcranial magnetic stimulation as treatment of poststroke depression: a preliminary study.

BACKGROUND: Depression has a significant impact on poststroke recovery and mortality. There are a proportion of patients with poststroke depression (PSD) who do not respond to antidepressants. Repetitive Transcranial Magnetic Stimulation (rTMS) might be a safe and effective alternative in these refractory cases. METHODS: We conducted a randomized, parallel, double-blind study of active versus sham left prefrontal rTMS in patients with refractory PSD. After discontinuing antidepressants, patients were randomly assigned to receive 10 sessions of active (10 Hz, 110% of the motor threshold, 20 trains of 5 seconds duration) or sham left prefrontal rTMS. Efficacy measures included HAM-D scores, response and remission rates. Patients completed a neuropsychological battery at baseline and after completing the protocol. RESULTS: When compared with sham stimulation, 10 sessions of active rTMS of the left dorsolateral prefrontal cortex were associated with a significant reduction of depressive symptoms. This reduction was not influenced by patient's age, type or location of stroke, volume of left frontal leukoaraiosis or by the distance of the stimulating coil to the prefrontal cortex. However, there was a significant positive correlation between the percentage of reduction of Ham-D scores and frontal gray and white matter volumes. There were no significant changes in cognitive functioning between the active and the sham stimulation groups. In addition, there were few and mild adverse effects that were equally distributed among groups. CONCLUSIONS: Taken together, these preliminary findings suggest that rTMS may be an effective and safe treatment alternative for patients with refractory depression and stroke.