Increased Prevalence of Rare Copy Number Variants in Treatment-Resistant Psychosis

BACKGROUND

It remains unknown why ~30% of patients with psychotic disorders fail to respond to treatment. Previous genomic investigations of treatment-resistant psychosis have been inconclusive, but some evidence suggests a possible link between rare disease-associated copy number variants (CNVs) and worse clinical outcomes in schizophrenia. Here, we identified schizophrenia-associated CNVs in patients with treatment-resistant psychotic symptoms and then compared the prevalence of these CNVs to previously published schizophrenia cases not selected for treatment resistance.

METHODS

CNVs were identified using chromosomal microarray (CMA) and whole exome sequencing (WES) in 509 patients with treatment-resistant psychosis (a lack of clinical response to ≥3 adequate antipsychotic medication trials over at least 5 years of psychiatric hospitalization). Prevalence of schizophrenia-associated CNVs in this sample was compared to that in a previously published large schizophrenia cohort study.

RESULTS

Integrating CMA and WES data, we identified 47 cases (9.2%) with at least one CNV of known or possible neuropsychiatric risk. 4.7% (n = 24) carried a known neurodevelopmental risk CNV. The prevalence of well-replicated schizophrenia-associated CNVs was 4.1%, with duplications of the 16p11.2 and 15q11.2-q13.1 regions, and deletions of the 22q11.2 chromosomal region as the most frequent CNVs. Pairwise loci-based analysis identified duplications of 15q11.2-q13.1 to be independently associated with treatment resistance.

CONCLUSIONS

These findings suggest that CNVs may uniquely impact clinical phenotypes beyond increasing risk for schizophrenia and may potentially serve as biological entry points for studying treatment resistance. Further investigation will be necessary to elucidate the spectrum of phenotypic characteristics observed in adult psychiatric patients with disease-associated CNVs.

Treatment-resistant psychotic symptoms and early-onset dementia: A case report of the 3q29 deletion syndrome

The 3q29 deletion is a rare copy number variant associated with neurodevelopmental and psychiatric disorders, including a >40-fold increased risk for schizophrenia. Current understanding of the clinical phenotype is derived primarily from published cases of patients in childhood or early adolescence. Symptoms include mild to moderate learning disability, developmental delay, facial dysmorphism, microcephaly, ocular disorders, and gastrointestinal abnormalities. There is, however, a lack of detailed longitudinal case studies describing 3q29 deletion syndrome in adults with psychosis. In this case report, we describe the lifetime clinical portrait of a 57-year-old woman with 3q29 deletion syndrome, treatment-resistant psychotic symptoms, multiple medical comorbidities, and a previously unreported co-occurrence of early-onset dementia.

Improved ethical guidance for the return of results from psychiatric genomics research

There is an emerging consensus that genomic researchers should, at a minimum, offer to return to individual participants clinically valid, medically important and medically actionable genomic findings (for example, pathogenic variants in BRCA1) identified in the course of research. However, this is not a common practice in psychiatric genetics research. Furthermore, psychiatry researchers often generate findings that do not meet all of these criteria, yet there may be ethically compelling arguments to offer selected results. Here, we review the return of results debate in genomics research and propose that, as for genomic studies of other medical conditions, psychiatric genomics researchers should offer findings that meet the minimum criteria stated above. Additionally, if resources allow, psychiatry researchers could consider offering to return pre-specified 'clinically valuable' findings even if not medically actionable-for instance, findings that help corroborate a psychiatric diagnosis, and findings that indicate important health risks. Similarly, we propose offering 'likely clinically valuable' findings, specifically, variants of uncertain significance potentially related to a participant's symptoms. The goal of this Perspective is to initiate a discussion that can help identify optimal ways of managing the return of results from psychiatric genomics research.

Successful Treatment of Severe Tardive Dyskinesia with Valbenazine, Including a Patient's Perspective

Patient: Female, 49

Final Diagnosis: Tardive dyskinesia

Symptoms: Dyskinesia • dystonia

Medication: —

Clinical Procedure: Oral valbenazine

Specialty: Psychiatry

Vaptans: a potential new approach for treating chronic hyponatremia in psychotic patients

OBJECTIVE

Hyponatremia (serum sodium concentration [Na+] <136 mEq/L) is a potentially life-threatening condition often found chronically in patients with psychotic disorders. Vasopressin antagonists have recently been shown in short-term studies to correct hyponatremia in diverse patient populations, including individuals with both psychosis and idiopathic hyponatremia. However, the safety and efficacy of long-term administration of vaptans is only beginning to be investigated. The objective of this study was to assess whether one of the vaptans, specifically tolvaptan, maintained its safety and efficacy over a prolonged period in patients with psychosis and chronic idiopathic hyponatremia.

METHODS

SALTWATER was a multicenter, open-label extension of the Study of Ascending Levels of Tolvaptan in Hyponatremia. Of the 111 patients enrolled in SALTWATER, eight were patients with both psychosis and idiopathic hyponatremia. These eight subjects provided a total of 7,406 patient days of exposure to oral tolvaptan.

RESULTS

Mean serum [Na+] in the eight psychotic patients increased from 131.6 mEq/L at baseline to >135 mEq/L throughout the observation period (p<0.05 versus baseline at most points). No drug-related adverse events led to study discontinuation.

CONCLUSIONS

Chronic hyponatremia is known to have deleterious effects on the quality of life for many patient groups. These preliminary results suggest that oral tolvaptan provides rapid, effective, and safe treatment of chronic hyponatremia in patients with psychotic disorders and that the effect is safely sustained over long periods of time. These findings represent an important step forward in treating a significant unmet need in psychotic populations.

Tolvaptan: a new tool for the effective treatment of hyponatremia in psychotic disorders

IMPORTANCE OF THE FIELD

Hyponatremia (serum sodium concentration < 136 mEq/liter) is a common and potentially life-threatening medical comorbidity seen in patients with psychotic disorders. Tolvaptan, a selective antagonist of the V(2)-receptor, is FDA-approved for the treatment of clinically significant hypervolemic and euvolemic hyponatremia. This represents a major development in the care of psychotic individuals with hyponatremia.

AREAS COVERED IN THE REVIEW

This review provides an overview of the existing literature on prevalence rates and risk factors associated with hyponatremia in psychotic patients (1923 - present). Tolvaptan is discussed as a potential advance in the treatment of hyponatremia in patients with psychotic disorders, and preliminary data are reviewed.

WHAT THE READER WILL GAIN

The reader will gain an appreciation of the prevalence of hyponatremia among psychotic individuals, an understanding of the distinctions between acute and chronic hyponatremia in this population, and awareness that effective treatments are becoming available.

TAKE HOME MESSAGE

A modest literature exists regarding prevalence rates and risk factors associated with hyponatremia in psychotic populations. Hyponatremia is common and serious enough to merit clinical concern. Perhaps, now that tolvaptan has been FDA-approved, progress will accelerate and new insights will develop that begin to bring relief from this medical comorbidity among psychotic patients.

Early intervention with second-generation antipsychotics in first-episode psychosis: results of an 8-week naturalistic study

OBJECTIVE

The objective was to compare short-term effectiveness of aripiprazole with three other second-generation antipsychotics (SGAs) in the treatment of first-episode psychosis.

METHOD

In a naturalistic, 'single-blind' design, 60 subjects experiencing their first psychotic episode were treated for 8 weeks with aripiprazole (n = 19), risperidone (n = 16), olanzapine (n = 14) or quetiapine (n = 11). Medication and dosing decisions were made by treating psychiatrists, constrained to once-a-day dosing, low initial doses and no clozapine. Weekly ratings were obtained using the Positive and Negative Syndrome Scale (PANSS), Simpson-Angus Rating Scale and Barnes Akathasia Rating Scale. Weight and vital signs were also collected weekly.

RESULTS

The group presented with severe psychotic symptoms (mean baseline PANSS total score of 105.2), which were reduced rapidly (P < 0.0005). The between-group and group by time interaction terms were non-significant. Similar reductions were seen across all PANSS sub-scales. At Week 1 the mean PANSS Activation Scale score was reduced more with olanzapine than in the other groups (P < 0.002). Few instances of extrapyramidal symptoms occurred; all were sporadic and did not require treatment. Group body weight increased by 7.3% over the study. Vital signs remained unchanged.

CONCLUSIONS

Early intervention with low doses of four SGAs led to rapid symptom reduction in first-episode psychotic patients with severe psychopathology. Although no clear medication advantages were observed in the short term, longer duration studies with larger samples will be required for determining efficacy, rates of compliance, relapse prevention and diminished incidence of extrapyramidal signs and symptoms.

Clozapine augmented with risperidone in the treatment of schizophrenia: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

The authors evaluated the efficacy and safety of augmenting clozapine with risperidone in patients with treatment-resistant schizophrenia.

METHOD

In a randomized, double-blind, placebo-controlled 12-week trial, 40 patients unresponsive or partially responsive to clozapine monotherapy received a steady dose of clozapine combined with either placebo (N=20) or up to 6 mg/day of risperidone (N=20). Patient psychopathology was assessed at 2-week intervals with the Brief Psychiatric Rating Scale (BPRS) and the Scale for the Assessment of Negative Symptoms (SANS), among other measures. Movement disorders were assessed with the Simpson-Angus Rating Scale.

RESULTS

From baseline to week 6 and week 12, mean BPRS total and positive symptom subscale scores were reduced significantly in both groups, but the reductions were significantly greater with clozapine/risperidone treatment. Reductions in SANS scores were also significantly greater with clozapine/risperidone treatment than with clozapine/placebo. The adverse event profile for clozapine/risperidone treatment was similar to that for clozapine/placebo. Simpson-Angus Rating Scale scores were lower with clozapine/risperidone treatment throughout the trial but increased to approach those of clozapine/placebo treatment at week 12. Clozapine/risperidone treatment did not induce additional weight gain, agranulocytosis, or seizures compared with clozapine/placebo treatment.

CONCLUSIONS

In patients with a suboptimal response to clozapine, the addition of risperidone improved overall symptoms and positive and negative symptoms of schizophrenia. The combination appears to be safe and well tolerated. Augmentation of clozapine with risperidone may provide additional clinical benefit for patients who are nonresponsive or only partially responsive to clozapine alone.

Effects of caffeine and PD 116,600 on the differential-reinforcement-of-low rate 72-S (DRL 72-S) schedule of reinforcement

Caffeine and PD 116,600 were found to decrease the reinforcement rate and increase the response rate in rats performing under a differential-reinforcement-of-low rate 72-s (DRL 72-s) schedule of reinforcement. In contrast, antidepressant drugs previously have been found to increase the reinforcement and decrease the response rate. Caffeine has been found to test similar to antidepressant drugs on at least one other behavioral screen, but caffeine does not possess clinical antidepressant properties. These results provide further support for the DRL 72-s schedule as a behavioral screen for antidepressant drugs.

Variability among brain regions in the specificity of 6-hydroxydopamine (6-OHDA)-induced lesions

6-Hydroxydopamine (6-OHDA; 200 micrograms, 150 micrograms or 110 micrograms) or vehicle was infused stereotaxically into the lateral ventricles of rats, usually following pretreatment with desmethylimipramine (DMI). Various brain regions were then assayed for dopamine (DA), serotonin (5-HT) and norepinephrine (NE). As expected, 6-OHDA depleted DA in all brain regions examined. Unexpectedly, however, the two highest doses of 6-OHDA significantly decreased 5-HT levels in the hippocampus and increased 5-HT levels in the striatum. In addition, despite pretreatment with doses of DMI commonly considered adequate to block 6-OHDA-induced depletion of NE, all doses of 6-OHDA tested significantly reduced NE levels in the hippocampus, hypothalamus and septum. We interpret our data as suggesting that some brain regions are susceptible to nonspecific toxic effects of 6-OHDA at doses commonly employed. Furthermore, these nonspecific effects may or may not occur, depending on seemingly minor variations in experimental technique.

The effect of water-deprivation on locomotor activity in rats treated with 6-hydroxydopamine

Male albino rats treated with 6-hydroxydopamine (6-OHDA) became more hyperactive than did vehicle-treated controls when both groups were water-deprived. Rats were treated with vehicle, 150 or 250 micrograms of 6-OHDA intraventricularly, after pretreatment with desmethylimpramine (25 mg/kg) and pargyline (50 mg/kg). Eleven days after these treatments, under ad libitum water conditions, the 6-OHDA-treated rats were slightly hypoactive. After several days of water-deprivation all three groups showed increased mean locomotor activity levels, but rats treated with 6-OHDA showed a much greater increase than did vehicle-treated rats. Under subsequent ad libitum and deprivation conditions, locomotor activity decreased and increased, respectively, in all 3 groups. Again, the changes in activity levels of the 6-OHDA-treated groups were greater than those of the vehicle-treated group. In addition, rats treated with 250 micrograms 6-OHDA seemed to become sensitized to the novel environment of the stabilimeter rather than habituating to it. Dopamine (DA) levels were decreased as a result of the injections of 6-OHDA, and significant correlations were found between DA levels in the caudate-putamen and nucleus accumbens, and locomotor activity levels. These results, as well as those obtained by others, suggest that there is an interaction among DA levels, deprivational states, and locomotor activity levels in rats.

Behavioral screen for antidepressants: the effects of drugs and electroconvulsive shock on performance under a differential-reinforcement-of-low-rate schedule

Those antidepressant drugs that are in wide clinical use decrease response rate and increase reinforcement rate when administered to rats performing on a differential-reinforcement-of-low-rate 72-s (DRL 72-s) schedule. Drugs that are not antidepressants do not have this effect. In this experiment, the following were examined for their effects on a DRL 72-s schedule: trazodone, zimelidine, fluoxetine, and bupropion (atypical antidepressants); electroconvulsive shock (ECS, which is an effective treatment for depression); and haloperidol and clozapine (antipsychotic drugs). Trazodone (3.12-25.00 mg/kg), fluoxetine (10-20 mg/kg), and ECS decreased response rate and increased reinforcement rate. Zimelidine (20 mg/kg) increased reinforcement rate and nonsignificantly decreased response rate. At doses between 2.5 and 40 mg/kg, bupropion had no effect on reinforcement rate or response rate, but at 60 mg/kg response rate was increased and reinforcement rate was nonsignificantly decreased. At the higher dose, the effects of bupropion resemble those of a psychomotor stimulant. Haloperidol (0.04 mg/kg) and clozapine (2.5-10.0 mg/kg) decreased response rate and reinforcement rate. These results suggest that the DRL 72-s schedule may be useful for testing the antidepressant potential of new drugs.