Guloksuz & van Os boldly challenge the status quo as pertains to schizophrenia. In ‘The Slow Death of the Concept of Schizophrenia, and the Painful Birth of the Psychosis Spectrum’ (Guloksuz & van Os, 2017) they thoughtfully review long-standing concerns about this diagnostic category and present a new conceptualization. The authors question the validity of the schizophrenia concept citing variable clinical outcomes, transdiagnostic manifestations of psychosis, and the difficulty in identifying biomarkers, among other concerns. They also point toward the over-representation of schizophrenia in the psychosis literature and lament that patients and clinicians have come to associate this illness with predominantly poor outcomes. Finally, they propose removing the diagnosis of schizophrenia from the diagnostic nomenclature and instituting a broad new classification system, ‘psychosis spectrum disorder’ (PSD), to capture the many manifestations of psychosis. In this commentary, we advise against the institution of a psychosis spectrum due to the potential negative effects this framework would have on clinical care and progress in biological research.

Intervention in the progression of schizophrenia is an effort not just to deter psychosis but also to protect the brain from physiologic deterioration. Neurodegeneration is believed to result from neurochemical dysregulation during the onset of schizophrenia. Deterioration accrued over recurring psychotic episodes causes cumulative loss of cell processes, loss of gray matter volume, and apoptosis. Neurodegeneration ultimately results in persistent symptomology and functional impairment. Functional decline occurs early in the course of schizophrenia, and the symptoms that emerge during the prodromal stage may derail the normal adolescent neurodevelopment. Both first-episode psychosis and the prodrome may be opportunities to forestall neurodegeneration. Unfortunately, people with schizophrenia often experience a long duration of untreated psychosis. Treatment of first-episode psychosis with antipsychotic agents shows robust response. However, early-stage patients have very high rates of medication noncompliance. Treatment in the prodrome may offer the best chance to delay the onset of illness, mitigate its severity after onset, or even prevent onset of symptoms entirely. Nonpharmacologic treatments during the prodrome, such as education, treatment for substance use, and cognitive-behavioral therapy, are low-risk interventions that are potentially beneficial. Pharmacologic interventions during the prodrome are also effective in delaying onset of illness, but carry the risk of adversely affecting patients who are false positives for prodromal schizophrenia.

In this Expert Roundtable Supplement, Jeffrey A. Lieberman, MD, provides an overview of the neurobiological basis of neurodegeneration and the concept of neuroprotection. Next, Peter F. Buckley, MD, reviews the importance of first-episode psychosis, including duration of untreated illness and medication adherence. Finally, Diana O. Perkins, MD, MPH, reviews treatment strategies for prodromal schizophrenia.

Clozapine is a prototype atypical antipsychotic drug and displays efficacy in 30% to 60% of schizophrenia patients who do not respond to traditional antipsychotics. There is considerable evidence supporting a concentration-response relationship for clozapine. A plasma clozapine concentration >200 to 420 ng/mL increases the probability of antipsychotic effects. Approximately 70% to 80% of variability in clozapine plasma concentration can be attributed to variability in cytochrome P450 1A2 activity. Measurement of caffeine metabolites in plasma or urine can be used as an in vivo index of cytochrome P450 1A2 activity, since caffeine is primarily eliminated by oxidative metabolism through this cytochrome P450 enzyme. Caffeine-based tests may contribute to individualization of clozapine dosages and optimization of its antipsychotic effects in schizophrenia patieents There are several lines of evidence suggesting the potential involvement of the dopamine D4 receptor in pharmacodynamic effects of clozapine. Clozapine has a 10-fold higher affinity for the dopamine D4 receptor in comparison to the D2 and the D3 receptors. Moreover, the free plasma fluid concentration of clozapine is comparable to its binding affinity for the D4 receptor in vitro. Blockade of the D4 receptor in the mesocorticolimbic region, a brain area implicated in the pathogenesis of schizophrenia, may contribute to efficacy of clozapine in negative symptoms. Moreover, the dopamine D4 receptor gene (DRD4) displays an unusual degree of genetic variation (polymorphism). In a recent preliminary study, investigated the (G)n mononucleotide repeat polymorphism within the first intron of the D4 gene in 50 schizophrenia patients refractory to traditional antipsychotics. These patients were prospectively followed for antipsychotic response during clozapine treatment. Analysis of variance found significant differences in antipsychotic response as demonstrated by mean change in Brief Psychiatric Rating Scale scores among the genotype panels for this polymorphism F[3,49]=4.1 (P=0.01). Future studies investigating the mechanistic basis of variability in response to clozapine should focus on both pharmacokinetic and pharmacodynamic factors.

Ziprasidone is a second-generation antipsychotic that received Food and Drug Administration approval in February 2001. It has a unique receptor profile that includes high-affinity antagonist activity at dopamine D2 receptors, inverse agonist activity at serotonin (5-HT)2A receptors, agonist activity at 5-HT1A receptors, and a relatively high affinity for the serotonin and norepinephrine transporters. The 5-HT1A affinity, together with the inhibitory effect on monoamine reuptake, may underlie the hypothesized beneficial effects on comorbid affective and cognitive abnormalities in schizophrenia and schizoaffective disorder. The short-term efficacy of ziprasidone for core positive symptoms of schizophrenia appears to be comparable to other conventional and atypical antipsychotics. The short-term efficacy of ziprasidone in acute mania has been established based on two 3-week, double-blind, placebo-controlled trials. Open-label treatment for up to 52 weeks confirms the sustained efficacy and safety of ziprasidone in bipolar disorder. Maintenance studies in schizophrenia and schizoaffective disorder indicate that long-term ziprasidone therapy is effective in preventing relapse, while maintaining cognitive and psychosocial benefits. The safety database suggests that the overall cardiovascular and cerebrovascular risk associated with ziprasidone is lower than with other atypicals, with notably lower risk of drug-related increases in weight, glucose, or lipids. The data also suggest a modestly increased risk of QTc prolongation that is not dose related or linked to torsades de pointes. Switching to ziprasidone from other atypicals appears to improve both clinical symptoms and metabolic parameters, though more studies are needed to fully characterize these benefits. This monograph summarizes the efficacy, tolerability, and safety of oral ziprasidone in the treatment of schizophrenia, schizoaffective disorder, and bipolar mania.

Schizophrenia is a neurodevelopmental disorder associated with persistent symptomatology, severe functional disability, and residual morbidity characteristic of neurodegenerative brain diseases. The illness begins with genetic susceptibility and generally expresses itself after puberty through subtle changes that begin during the prodromal stage. Symptoms get progressively worse and tend to become more resistant to treatment with each relapse. Evidence for a neuroprotective effect of some forms of early treatment is beginning to emerge. While the underlying mechanisms remain uncertain, atypical antipsychotics may counteract some of the progressive deteriorative effects by enhancing synaptic plasticity and cellular resilience. However, identifying and treating patients in the earliest disease states presents methodological challenges as there is no consensus on the best methods of intervention and differences in at-risk children are not readily detectable or substantial enough to predict which ones will develop schizophrenia.

In this expert roundtable supplement, Jeffrey A. Lieberman, MD, reviews the historical context of progressive deterioration in schizophrenia. Next, Diana O. Perkins, MD, MPH, reviews some of the challenges to early identification of illness as well as the impact of early versus delayed treatment. Finally, L. Fredrik Jarskog, MD, focuses on the neurobiology of functional progression in schizophrenia as well as pharmacology and the potential for neuroprotection.