A comparison of olanzapine with haloperidol in cannabis-induced psychotic disorder: a double-blind randomized controlled trial

Little controlled data exist on the treatment of substance induced psychotic disorders. In this study, 30 patients meeting DSM-IV criteria for cannabis induced psychotic disorder were randomly allocated to receive either olanzapine or haloperidol in a 4-week double-blind clinical trial. There were no significant outcome differences between the two groups on any of the primary outcome measures, the Brief Psychiatric Rating Scale (haloperidol 25.7; olanzapine 27.1; P = 0.70); Clinical Global Impression (CGI) severity scale (haloperidol 1.8, olanzapine 2.3; P = 0.21) or the CGI improvement scale (haloperidol 1.3, olanzapine 1.7; P = 0.16). The haloperidol group however, developed significantly more extrapyramidal side-effects as measured by the Simpson Angus Scale (haloperidol 11.4, olanzapine 2.5; P = 0.014). Significantly (P = 0.027) more biperidin was used for extrapyramidal side-effects in the haloperidol (7.143 mg) than in the olanzapine (0.357 mg) group. Olanzapine appears to be as effective as haloperidol in the treatment of cannabis induced psychotic disorder, but is associated with a lower rate of extrapyramidal side-effects.

The potential utility of a staging model as a course specifier: a bipolar disorder perspective.

Staging models are widely used in clinical medicine, and offer an insight into the progressive nature of many disorders. In general, the earlier stages of illness may be associated with a better prognosis and a higher treatment response. Once chronicity is reached, more complex and invasive treatments may be required, and the utility of treatments may decline. There is evidence that treatment response is greatest in the early phases of the disorder. There is also a progressive social and psychological burden of ongoing illness. This is paralleled by the twin notions of neuroprotection, which is supported by increasing evidence that structural changes in the disorder may be progressive and reversible with algorithm appropriate treatment, and that of early intervention, which posits that the optimal window for intervention is early in the illness course. A staging model compliments existing and proposed classifications of bipolar disorder, adding a temporal dimension to a cross sectional view. It may inform treatment choice and prognosis, and could have utility as a course specifier.

The role of lamotrigine in the management of bipolar disorder.

Lamotrigine has emerged with a distinct place in the pharmacological treatment of bipolar disorder, with the potential to treat and prevent bipolar depression, which is the dominant and arguably most disabling and under-treated phase of the illness. This review examines the published clinical trials of lamotrigine in bipolar treatment. While the data supports its tolerability and safety, the strongest evidence for its efficacy lies in the prevention of bipolar depression, with weaker evidence for the treatment of acute bipolar depression, refractory unipolar and bipolar depression, and rapid cycling bipolar disorder. The total number of published well designed trials is small, even the maintenance evidence is derived from two studies. However, this relative inadequacy compares favorably with the alternative treatment options for bipolar depression, which are marked by poor efficacy or risk of polarity switch. The designation of lamotrigine as first-line treatment for bipolar depression prophylaxis should be done in cognizance of this context, and it would seem prudent to await greater evidence of efficacy before designating lamotrigine as first-line treatment for other bipolar indications. Further randomized controlled trials are required to consolidate the available findings and to explore the boundaries of lamotrigine's efficacy, which may encompass the soft spectral disorders.

Lamotrigine and the treatment of mania in bipolar disorder

Anticonvulsants, including valproate and carbamazepine, have established efficacy in the treatment of mania. The anticonvulsant, lamotrigine. has been reported to have antimanic and antidepressant efficacy, and mood-stabilising effects in case reports and preliminary open trials. The efficacy and tolerability of lamotrigine has been compared with olanzapine and lithium in a randomised, prospective, controlled fashion over a period of 4 weeks treatment in a total of 45 hospitalised patients with DSM-IV-defined mania. Significant improvements of a similar magnitude were observed for all treatment groups and lamotrigine was well tolerated. Mechanisms of action proposed to explain the antimanic activity of lamotrigine include inhibition of voltage-sensitive and use-dependent sodium channels, inhibition of glutamate release and calcium channel blockade. Platelet studies have indicated supersensitivity of glutamate receptors and increased intracellular calcium concentrations in patients with mania. Further clinical and mechanistic studies of lamotrigine use in mania are warranted.

Mood stabilizers and treatment adherence in bipolar disorder: addressing adverse events.

Adverse events associated with lithium and anticonvulsant use in patients with bipolar disorder have been determined to decrease rates of treatment adherence; however, research that explores how adverse events influence treatment adherence, and which events have the greatest impact, is sparse and limited. This paper reviews the existing literature regarding common side effects encountered with lithium and anticonvulsant use in patients with bipolar disorder and presents data regarding their impact on treatment adherence. Guidelines for reducing and limiting adverse events are highlighted, as are recommendations for improving compliance associated with the experience of adverse events in the bipolar disorder population.

Pharmacotherapy of bipolar disorder: the role of atypical antipsychotics and experimental strategies.

Bipolar disorder, despite being a common and debilitating illness, has remarkably few pharmacological therapeutic options, the majority of which, with the exception of lithium, have been borrowed from other medical indications. Furthermore the quantity and quality of controlled clinical data are considerably smaller than in conditions of comparable severity and frequency. Not surprisingly, the clinical outcome of bipolar disorder is frequently suboptimal. Fortunately there are a growing number of novel therapeutic options for its treatment such as atypical antipsychotics, calcium channel blockers and omega-3 fatty acids. This paper summarizes some of the data regarding these "experimental" therapeutic options, focusing principally on atypical antipsychotics as these are now widely prescribed in the management of bipolar disorder.

Platelet glutamate receptor supersensitivity in major depressive disorder.

Dysregulation of glutamate has been described in depression, and supersensitivity of platelet glutamate receptors has been found in both psychotic major depression and schizophrenia. The aim of this study was to examine the platelet glutamate receptor sensitivity in patients with nonpsychotic, unipolar major depression to assess whether this is a marker of depression or of psychosis. Glutamate receptor sensitivity was assessed using the platelet intracellular calcium response to glutamate (0-100 micromol) measured by spectrofluorometry. The depression group showed a significantly greater platelet intracellular calcium response to glutamate stimulation than the control group, both in terms of absolute values (p = 0.007) and percentage of response from baseline (p = 0.030). These data suggest that platelet glutamate receptors may be supersensitive in depression and that the platelet may be a possible peripheral marker of glutamate function in depression.

Serum levels of brain-derived neurotrophic factor in patients with schizophrenia and bipolar disorder.

There is evidence that major psychiatric discords such as schizophrenia (SZ) and bipolar disorder (BD) are associated with dysregulation of synaptic plasticity with downstream alterations of neurotrophins. Brain-derived neurotrophic factor (BDNF) is the most widely distributed neurotrophin in the central nervous system (CNS), and performs many biological functions such as promoting the survival, differentiation, and plasticity of neurons. Variants in the BDNF gene increase the risk of SZ and bipolar disorder. Chronic administration of drugs used to treat SZ and BD, such as lithium, valproate, quetiapine, clozapine, and olanzapine, increases BDNF expression in rat brain. To examine serum BDNF, three groups of chronically medicated DSM-IV SZ patients, on treatment with clozapine (n=27), typical (n=14), and other atypical antipsychotics (n=19), 30 euthymic BD patients, and 26 healthy control had 5 ml blood samples collected by venipuncture. Serum BDNF levels were significantly higher in SZ patients (p<0.001) when compared to either controls or euthymic BD patients. Increased BDNF in SZ patients might be related to the course of illness or to treatment variables. Prospective studies are warranted.