On schizophrenia and new generation drugs

Speech disturbances and quality of life in schizophrenia: differential impacts on functioning and life satisfaction

Speech disturbances in schizophrenia impact on the individual's communicative ability. Although they are considered a core feature of schizophrenia, comparatively little work has been done to examine their impact on the life experiences of patients. This study aimed to examine the relationship between schizophrenia speech disturbances, including those traditionally known as formal thought disorder (TD), and quality of life (QoL). It assessed effects on functioning (objective QoL) and satisfaction (subjective QoL) concurrently, while controlling for the influence of neurocognition and depression. Fifty-four patients with schizophrenia/schizoaffective disorder were administered the MATRICS Consensus Cognitive Battery (MCCB), the PANSS, MADRS (with separate ratings for negative TD [verbal underproductivity] and positive TD [verbal disorganisation and pressured speech]) and Lehman's QOLI assessing both objective and subjective QoL. Ratings of positive and negative TD, depression, and general neurocognition were entered into hierarchical regressions to explore their relationship with both life functioning and satisfaction. Verbal underproductivity was a significant predictor of objective QoL, while pressured speech had a trend association with subjective QoL. This suggests a differential relationship between speech disturbances and QoL. Verbal underproductivity seems to affect daily functioning and relations with others, while pressured speech is predictive of satisfaction with life. The impact of verbal underproductivity on QoL suggests it to be an important target for rehabilitation in schizophrenia.

Clozapine: key discussion points for prescribers

Clozapine is the most effective antipsychotic medication for treatment-refractory schizophrenia and is also approved for suicidality in schizophrenia patients. However, it can cause significant medical morbidity and requires intensive medical monitoring once prescribed. Perhaps due to lack of familiarity with its use, it is underused in clinical practice and its initiation often delayed. This article reviews the literature on clozapine in order to measure its potential effectiveness against its adverse effects and ultimately aims to serve as a useful summary for clinicians in their everyday prescribing.

Differential effects of within-day continuous vs. transient dopamine D2 receptor occupancy in the development of vacuous chewing movements (VCMs) in rats

Accumulating evidence suggests that antipsychotics (APs) that lead to sustained blockade of dopamine D(2) receptors are more likely to induce acute extrapyramidal side effects (EPS) compared to APs that only occupy D(2) receptors transiently. It is unclear, however, whether a similar relationship exists for long-term AP-induced motoric side effects like tardive dyskinesia (TD). The objective of this study was to ascertain whether transient (via daily subcutaneous (s.c.) injections) vs continuous (via osmotic minipump) AP-induced D(2) receptor occupancy differentially affects the development of haloperidol-induced vacuous chewing movements (VCMs), an animal model of TD. Six groups of 12 rats received 0.1, 0.25, or 1 mg/kg of haloperidol or vehicle (n=36) via osmotic minipump (to provide within-day sustained) or daily s.c. injection (within-day transient) for 8 weeks. VCMs were measured on a weekly basis and D(2) occupancy levels were measured in vivo using [(3)H]-raclopride at the end of the experiment. Minipump-treated rats developed HAL dose-dependent D(2) occupancies of 0.1 mg/kg/day (57%), 0.25 mg/kg/day (70%), and 1 mg/kg/day (88%). S.C.-treated rats also developed HAL dose-dependent D(2) occupancies of 0.1 mg/kg/day (83% peak, 3% trough), 0.25 mg/kg/day (89% peak, 0% trough), and 1 mg/kg/day (94% peak, 17% trough). A total of 43% of rats given 0.25 and 1 mg/kg/day of HAL via minipump developed high VCMs compared to only 8% of the rats given the same doses via daily s.c. injections. The 0.1 mg/kg dose did not give rise to VCMs beyond vehicle levels regardless of the route of administration. These findings support the contention that D(2) occupancy levels induced by chronic HAL must be high and sustained through the day before significant risk of VCMs, and perhaps also TD, emerges.