Lurasidone is an atypical antipsychotic medication approved for the treatment of schizophrenia over a dose range of 40–160 mg/day. This study examined D2 receptor occupancy and its association with clinical improvement and side effects in patients with schizophrenia or schizoaffective disorder following repeated doses of 80, 120, or 160 mg/day of lurasidone.

Twenty-five patients with The Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) diagnoses of schizophrenia or schizoaffective disorder were washed out of their antipsychotic medications (5 half-lives) and randomly assigned to 80, 120, or 160 mg/day of lurasidone. Subjects were imaged with 18F-fallypride at baseline and at steady-state lurasidone treatment to determine D2 receptor occupancy.

Blood lurasidone concentration (plus major metabolite), but not dose, significantly correlated with D2 receptor occupancy. D2 receptor occupancy in several subcortical structures is associated with positive but not negative symptom improvement or the presence of movement symptoms.

Blood concentrations greater than 70 ng/mL may be required to achieve a 65% occupancy level in subcortical areas. Intersubject blood concentrations at fixed dose were highly variable and may account for the lack of dose correlations.

Positron emission tomography (PET) occupancy data suggest that greater than 65% occupancy can be achieved across the dose range of 80–160 mg/day and that some patients require higher doses to achieve antipsychotic efficacy; this finding supports prior randomized clinical trial results.

We evaluated sexual functioning from 6 acute, randomized, placebo-controlled studies (6–10 weeks) of once-daily extended release quetiapine fumarate (quetiapine XR) 50, 150, or 300 mg/day as monotherapy (Studies 1–4) or adjunct therapy (Studies 6–7) in major depressive disorder (MDD).

We present a pre-planned, non-inferiority analysis of quetiapine XR monotherapy versus placebo using Changes in Sexual Functioning Questionnaire (CSFQ) total score change (Studies 1–4). Post hoc analyses evaluated CSFQ total and domain scores for fixed-dose monotherapy (Studies 1–2), modified fixed-dose (Studies 3–4), and adjunct therapy studies (Studies 6–7). CSFQ data for active comparators (duloxetine [Study 2], escitalopram [Study 4]) are reported.

Quetiapine XR monotherapy was non-inferior to placebo for sexual functioning (least squares mean [LSM] difference in CSFQ score change versus placebo, 0.16 [95% confidence interval: −0.59, 0.92]); LSM change in CSFQ score: 1.90, quetiapine XR (all doses) and 1.73, placebo. LSM differences versus placebo (95% confidence interval): 0.18 (−1.40, 1.75), duloxetine (Study 2); 0.16 (−1.77, 2.10), escitalopram (Study 4). LSM differences with adjunct quetiapine XR 150 mg/day (0.52; p = 0.338) or 300 mg/day (0.22; p = 0.679) were comparable with placebo plus antidepressants. Post hoc all-patient and gender-specific analyses were comparable for CSFQ total scores versus placebo with quetiapine XR 50, 150, or 300 mg/day, duloxetine, and escitalopram.

Lack of negative effects on sexual functioning in patients with MDD may improve treatment acceptability.

Quetiapine XR (monotherapy or adjunct therapy) had an impact on sexual function that was comparable with placebo.

Resolving the entangled nosological dilemma of whether obsessive-compulsive disorder (OCD) with and without schizophrenia (schizo-OCD and OCD, respectively) are two independent entities or whether schizo-OCD is a combined product of its parent disorders.

Studying motor activity in OCD and in schizo-OCD patients. Performance of the patients was compared with the performance of the same motor task by a matching control individual.

Behavior in both schizo-OCD and OCD patients differed from controls in the excessive repetition and addition of acts, thus validating an identical OC facet. However, there was a significant difference in spatial behavior. Schizo-OCD patients traveled over a greater area with less focused activity as typical to schizophrenia patients and in contrast to OCD patients, who were more focused and traveled less in a confined area. While schizo-OCD and OCD patients share most of the OC ritualistic attributes, they differ in the greater spread of activity in schizo-OCD, which is related to schizophrenia disorder.

It is suggested that the finding on difference in spatial behavior is a reflection of the mental differences between OCD and schizophrenia. In other words, this could be an overt and observable manifestation of the mental state, and therefore may facilitate the nosology of OC spectrum disorders and OCD.

It seems as if both the OCD patients’ focus on specific thoughts, and the contrasting wandering thoughts of schizophrenia patients, are reflected in the focused activity of the former and wandering from one place to the next of the latter.

The aim of this analysis was to compare the effects of 2 atypical antipsychotic agents, lurasidone (80 mg/d or 160 mg/d) and quetiapine XR (600 mg/d), on daytime alertness, and to evaluate the effects of daytime sleepiness on treatment outcomes in patients with an acute exacerbation of schizophrenia.

Patients who met Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision (DSM-IV-TR) criteria for schizophrenia were randomized to 6 weeks of double-blind treatment with fixed doses of lurasidone 80 mg/d (n = 125), lurasidone 160 mg/d (n = 121), quetiapine XR 600 mg/d (n = 119), or placebo (n = 121), all dosed once daily in the evening, with food. Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS).

Daytime sleepiness improved in the lurasidone and placebo-treated groups but worsened in the quetiapine XR treatment group when compared to placebo (p = 0.001) and to either dose of lurasidone (both p < 0.01). Sedation associated with quetiapine XR treatment mediated an improvement in agitation [assessed by the Positive and Negative Syndrome Scale—Excitement (PANSS-EC) subscale] and a worsening in functional capacity [assessed by the University of California–San Diego (UCSD) Performance-Based Skills Assessment—Brief Version (UPSA-B) total score]; these mediating relationships were not observed for the lurasidone or placebo treatment groups.

In this 6-week double-blind study, treatment with lurasidone 80 mg or 160 mg, administered once daily in the evening, was associated with a reduction in daytime sleepiness similar in magnitude to placebo, while quetiapine XR 600 mg/d was associated with a significant increase in daytime sleepiness, compared to both lurasidone dose groups and placebo. Daytime sleepiness was associated with improvement in agitation and worsening in functional capacity for quetiapine XR, but not lurasidone or placebo-treated patients.