What Happens to First-Episode Patients After 5 Years?

Following a first episode of psychosis, patients always want to know when they can stop taking medication. Adverse effect such as weight gain or sedation may play a role, but the need to take a daily pill or receive an injection may be inconvenient or stigmatizing no matter the side effects. Existing evidence suggests a high risk of relapse during the first 5 years if medication is discontinued, up to a 5-fold compared to continuous medication treatment, although longer-term outcomes remain uncertain. Two new studies provide further evidence about outcomes longer than 5 years.

In 2003, Drs. Eric Chen, Bill Honer and collaborators in Hong Kong initiated a randomized trial with 178 first-episode patients in several clinics. To be eligible, patients had to be free of positive symptoms during at least 12 months on medication; the mean was 21.9 months. They then received either quetiapine 400 mg daily or placebo for a year or until relapse. Following the RCT, the patients returned to the community for usual clinical care.

Ten years later, the research team followed up the 178 patients; they performed a chart review on all and interviewed 142 of them. A poor outcome was defined as death by suicide, need for clozapine treatment, or persistent positive symptoms measured by the Positive and Negative Syndrome Scale (PANSS). Of 138 patients with adequate follow-up data, 110 were taking antipsychotic medication; the mean dose was 355 chlorpromazine equivalents.

Of those subjects assigned to a year of quetiapine treatment in the RCT 10 years before follow-up, 21% had a poor outcome; of those assigned to placebo in the RCT, 39% had a poor outcome. The relative risk was 1.84 (P = 0.012). Six patients died by suicide and 11 required clozapine; the incidence of these outcomes individually did not significantly differ between the groups. The investigators also found that among subjects originally assigned to medication discontinuation, i.e. placebo, relapse of psychosis during the first 2-3 years of diagnosis seemed to mediate the elevated risk of poor outcomes.

In Finland, Dr. Jari Tiihonen and his group performed a 20-year follow up on all persons hospitalized for schizophrenia for the first time during 1972–2014. Given that everyone in Finland has health and pharmacy services recorded in a national data registry, it was possible to determine who was readmitted to hospital and who filled prescriptions for antipsychotics. Based on this data, the researchers looked at whether subjects were taking medication or had been rehospitalized at various time points and then classified them as either antipsychotic users or nonusers. I suggest readers go to the original article to gain a full understanding of the methods.

Treatment failure was defined as rehospitalization or death. The table below shows the interesting finding that patients who continued antipsychotic treatment throughout the follow-up period had the lowest risk of relapse or death, but those risks rose as a function of the duration of treatment preceding discontinuation. In other words, stopping medication after several years of stability may be more associated with poor outcome than stopping it very soon after the first episode. However, compared to those who were treated continuously, the groups that discontinued treatment at any interval had a higher rate of poor outcome.

Adjusted Hazard Ratio chart

FIGURE: Adjusted hazard ratios as a function of duration of antipsychotic use prior to discontinuation.

The number of deaths was relatively small, but available data allowed the calculation of hazard ratios in 3 matched groups: those who discontinued antipsychotic treatment within the first year, those who remained on antipsychotics throughout, and those who did not use antipsychotics.  In 3057 subjects, 91 deaths occurred; compared with continuous antipsychotic users, nonusers had a 214% higher risk of death (hazard ratio, 3.14; 95% CI, 1.29–7.68), and those who discontinued within a year had a 174% higher risk of death (hazard ratio, 2.74; 95% CI,1.09–6.89).

These studies have important limitations, given their retrospective nature and the lack of details about important outcomes related to function and comorbidities. Nonetheless, they bring new understandings to the role of antipsychotic therapy after the first few years of psychotic illness: patients who go untreated have a higher risk of remaining psychotic and of dying. But the finding that discontinuation after 5 or more years of antipsychotic therapy is highly associated with relapse suggests that stopping medication in chronic patients is risky.

References

Hui CLM, Honer WG, Lee EHM, Chang WC, et al. Long-term effects of discontinuation from antipsychotic maintenance following first-episode schizophrenia and related disorders: a 10 year follow-up of a randomised, double-blind trial. Lancet Psychiatry. 2018;5(5):432-442.

Tiihonen J, Tanskanen A, Taipale H. 20-Year nationwide follow-up study on discontinuation of antipsychotic treatment in first-episode schizophrenia. Am J Psychiatry. Published online Apr 6, 2018:

Meta-Analysis Conundrums

For patients whose psychosis doesn’t adequately respond to antipsychotics, especially clozapine, treatment options include electroconvulsive therapy, cognitive-behavior therapy, and augmentation with another medication. Investigators have done cotreatment trials with other antipsychotics, anticonvulsant/mood stabilizers, and even the antibiotic minocycline and anti-inflammatory agents such as aspirin. The trials are small in many cases, so meta-analyses allow various trials to be pooled. Two recent publications give some new guidance but also may sow confusion.

One team examined clinical trials of the anticonvulsants lamotrigine, topirimate and valproate added to clozapine. They included 22 randomized controlled trials (RCTs) comprising 1227 subjects; 613 received clozapine alone, whereas the others received, in order of frequency, valproate, lamotrigine or topirimate. The primary outcome was change in Positive and Negative Syndrome Scale (PANSS) or Brief Psychiatric Rating Scale (BPRS) total score. The analysis showed no significant effect for lamotrigine, confirming a previous meta-analysis, but also confirming a prior analysis, topirimate was superior to clozapine alone for reduction in total, positive and negative psychotic symptoms ratings. Sodium valproate, but not magnesium valproate, was superior to clozapine alone in reducing total and positive psychotic symptom scores; it was not effective for negative symptoms. In terms of tolerability, topirimate but not valproate had a significant all-cause discontinuation rate compared to clozapine monotherapy.

One of the limitations of this pooled data set was that many of the patients were not clearly designated as having clozapine resistance; for instance, clozapine serum levels were not recorded. Another concern was that all the trials for valproate augmentation were done in China, and the generalizability to other settings and ethnic groups is uncertain.

The anticonvulsant meta-analysis is one of many that has examined antipsychotic augmentation, which prompted a group led by Christoph Correll to do a meta-meta-analysis. Summarizing this article will not do it justice, so I recommend reading it in its entirety. The investigators looked at 29 existing meta-analyses of trials of augmentation of any antipsychotic with any of 42 medications including, mood stabilizers, anticonvulsants, antidepressants, minocycline, a second antipsychotic, or various hormones such as estrogenic agents. They applied a novel method to assess the quality of the meta-analyses, AMSTAR-Plus Content. Five of the meta-analyses looked at augmentation of clozapine.

In combination with clozapine for positive symptoms of psychosis, only glycine, an amino acid which modulates the NMDA glutamate receptor, had a significant effect size. No treatments showed efficacy in combination with clozapine for total psychopathology or negative symptom scores. In combination with non-clozapine antipsychotics, lamotrigine, estrogenic agents, mirtazapine and a few others showed efficacy.

An important finding is buried in the discussion: “When all this metanalytic literature was compared regarding the quality of its meta-analyzed content, the effect sizes were inversely correlated with the study quality, reducing confidence in these affirmative recommendations.” In other words, many of the studies in this uber-study were small or contained biases, and those studies tended to overrate the effects of the adjunctive treatments. They point out that individual patients may benefit from specific interventions, but the evidence to guide treatment selection is lacking. This leaves the clinician without clear direction for the most difficult-to-treat patients. In an accompanying editorial, however, Wolfgang Fleishhacker suggests that this meta-analysis does not necessarily invalidate all preceding analyses.

References

Zheng W, Xiang YT, Yang XH, Xiang YQ, de Leon J. Clozapine Augmentation with Antiepileptic Drugs for Treatment-Resistant Schizophrenia: A Meta-Analysis of Randomized Controlled Trials. J Clin Psychiatry. 2017;78(5):e498-e505. Abstract

Correll CU, Rubio JM, Inczedy-Farkas G, Birnbaum ML, Kane JM, Leucht S. Efficacy of 42 Pharmacologic Cotreatment Strategies Added to Antipsychotic Monotherapy in Schizophrenia: Systematic Overview and Quality Appraisal of the Meta-Analytic Evidence. JAMA Psychiatry. 2017;74(7):675-684. Astract

Raloxifene as adjunctive treatment for chronic psychosis

Psychosis and mood symptoms are sometimes exacerbated  during times of hormonal flux in women such as postpartum and during menopause. Research from Australia has suggested that estradiol may ameliorate psychosis in women with schizoaffective disorder or schizophrenia. The same Australian team has recently published a randomized controlled trial of raloxifene in postmenopausal women with those diagnoses; raloxifene is an estrogen receptor modulator that may be safer than estradiol as it is less likely to provoke hormone-influenced cancers. However, it does entail an increased risk of thromboembolism.

The 56 subjects had a mean age of 53 years and a mean illness duration of 24 years, all were on antipsychotic therapy, and none was deemed at baseline to have elevated risk for thrombotic disease or evidence of reproductive cancers. They were randomly assigned to receive 120 mg of raloxifene or placebo for 12 weeks as cotreatment with their psychiatric medications; 8 patients were taking clozapine, 5 in the active treatment group. The primary outcome measure was the Positive and Negative Syndrome Scale (PANSS); the investigators also monitored depression, movement disorder, cognitive function, and safety measures.

At the end of 12 weeks, the women receiving raloxifene had a significant reduction in the PANSS total and general scores, whether the diagnosis was schizophrenia or schizoaffective disorder; the PANSS positive and negative symptom subscales showed no significant improvement with raloxifene. Significantly more subjects who received raloxifene had a clinical response defined as a 20% reduction in PANSS total score (P = 0.01).  Measures of depression and cognition did not show any difference between the groups and adverse events were minimal; no thromboembolic events occurred in either group.

Raloxifene may help prevent osteoporosis and breast cancer, so it confers benefits beyond ameliorating symptoms of chronic psychosis. It has also been trialed in men cotreated with risperidone during an 8-week study in Iran; compared with placebo, the active treatment resulted in improvement in the PANSS total score and the negative and general subscale scores (2). Adverse effects did not occur more often with raloxifene, although the researchers admit that with longer-term treatment, gynecomastia and infertility would be possible which would greatly limit its utility in men.

References

1.Effect of adjunctive raloxifene therapy on severity of refractory schizophrenia in women: a randomized clinical trial. Kulkarni J, Gavrilidis E, Gwini SM, et al. JAMA Psychiatry. 2016;73(9):947-354. Abstract

2.Khodaie-Ardakani MR, Khosravi M, Zarinfard R, et al. A placebo-controlled study of raloxifene added to risperidone in men with chronic schizophrenia. Acta Med Iran. 2015;53(6):337-345. Full text

 

Twenty percent of schizophrenia may be treatment-resistant from onset

About 30% of people with schizophrenia do not have adequate response to antipsychotic medications other than clozapine. Treatment-resistant psychosis has no well-established predictors although early-onset psychosis and prolonged duration of untreated psychosis may be risk factors. The Genetics and Psychosis study based in South London, UK, enrolled 283 patients with schizophrenia-spectrum disorders in their first episode who underwent assessments including the Positive and Negative Syndrome Scale, Global Assessment of Functioning, and the Weschler Adult Intelligence Scale. The cohort had follow-up investigations 5 years after first assessment by means of the WHO Life Chart Schedule, intended for documenting the longitudinal course of schizophrenia.

Patients were determined to have treatment-resistant schizophrenia (TRS) if they were either treated with clozapine or failed to respond to 2 consecutive, adequate trials of non-clozapine antipsychotics. Remission of psychosis was defined as absence of overt psychotic symptoms for 6 months or more. The investigators classified the TRS as either early-onset or late-onset. Early onset TRS occurred when no remission occurred at any time whereas late-onset occurred when resistance developed after an interval of remission.

Of the original cohort, 246 or 87% had follow-up data. Four patients had died, and their mean age was significantly older than the cohort as a whole. In 33.7%, TRS had developed and their only distinguishing characteristic was a younger age of contact for treatment of psychosis: 25.2 years versus 27.9 years in the non-TRS group. Family history of psychosis, use of alcohol or cannabis, cognitive performance, and duration of untreated psychosis (DUP) did not differ between TRS and non-TRS groups. Those patients who were younger than 20 years at the time of first contact had an odds ratio of 2.49 for developing TRS, and men and Black people were also more likely to have TRS at follow-up.

About 70% of TRS patients had early-onset treatment resistance. Compared to the non-TRS group, those with early-onset TRS had a higher mean total PANSS score at baseline; 74% were male compared to 46% in the late-TRS group.

In the TRS cohort, about half the patients received clozapine, and they had on average a greater burden of total psychopathology and negative symptoms compared to the TRS patients who never received clozapine. The clozapine patients were also more likely to reside with family or friends.

According to the investigators, this is the largest first-episode cohort followed for onset of treatment resistance. They estimate that 23% of their patients had resistance to antipsychotic therapy from the onset of illness, and given the mean DUP of 4.5 weeks, which is quite brief, factors other than delayed treatment seem to be at play. If this study is generalizable, only a third of treatment resistance develops after the  onset of illness, and understanding that process could lead to prevention strategies. Furthermore, availability of biomarkers for TRS in early psychosis populations might help determine which patients would benefit from receiving clozapine immediately.

Lally J et al. Psychol Med. 2016;46(15):3231-3240. Abstract

Benzodiazepines may increase the risk of death in people with schizophrenia

Patients with psychosis often accumulate medications during hospitalizations and changes in prescribers. The use of multiple medications, often with uncertain benefit, is called polypharmacy. The use of more than one antipsychotic is considered problematic and may increase the risk of adverse effects such as weight gain and diabetes, but other kinds of psychiatric medications often accumulate as well, including antidepressants and benzodiazepines. The latter are used for a variety of reasons, often for acute agitation in an emergency setting, but also for insomnia or chronic anxiety. They may be associated with tolerance, escalating dosage and dependence, although overall are considered safe medications.

Population-based studies from Finland and Denmark have revealed that patients with schizophrenia, however, may be at elevated risk for death when treated with a benzodiazepine.  Now the same has been found in a US cohort. Researchers from Ohio State University examined outpatients covered by US Medicaid, age 18 to 58 years old, who had received a diagnosis of schizophrenia during 2007 to 2009. They looked at prescription claims for benzodiazepines, antipsychotics, antidepressants and mood stabilizers from time of diagnosis through 2013. They then examined death certificate files for deaths among the 18,953 identified subjects and calculated hazard ratios for all-cause mortality, death from suicide and accidental poisoning, and death by natural causes.

Of 18,953 patients with schizophrenia, 3,476 received a benzodiazepine, and those subjects were more often Caucasian females who were separated or divorced. The top 3 benzodiazepines prescribed were, in order, lorazepam, clonazepam and alprazolam. In patients taking an antipsychotic, in comparison with those who had no added benzodiazepine, the adjusted hazard ratio after initiating a benzodiazepine was 1.48, i.e. a 48% increased risk of death during the time of cotreatment. For patients who received only a benzodiazepine and no antipsychotic or other medication, the adjusted hazard ratio was 3.08. The calculated mortality rate per 1000 person-years was significantly elevated in every examined combination of medications, e.g. for a mood stabilizer alone, or for an antidepressant plus an antipsychotic, when a benzodiazepine was added. Furthermore, the risks of death from suicide, accidental poisoning and natural causes were all elevated.

The investigators caution that this is an association, and that benzodiazepines cannot yet be implicated as a definite cause of premature mortality in people with schizophrenia. However, this evidence adds to existing epidemiologic findings to make the risk-benefit ratio of benzodiazepine prescription less favorable. The possible mechanisms behind the risk could be multiple, and the researchers mention lower mood and impulsiveness which may occur during benzodiazepine use along with withdrawal-related anxiety as factors that could elevate risk of suicide. As for natural causes, some evidence exists for heightened incidence of infectious diseases concomitant with benzodiazepine use. Prospective studies and larger epidemiologic investigations are required to understand this association, but prescribers should always keep in mind the maxim “do no harm” and attempt to eliminate unnecessary medications.

Reference

Fontanella CA, Campo JV, Phillips GS, Hiance-Steelesmith DL, Sweeney HA, Tam K, Lehrer D, Klein R, Hurst M. Benzodiazepine use and risk of mortality among patients with schizophrenia: a retrospective longitudinal study. J Clin Psychiatry. 2016;77(5):661-667. Abstract

Topirimate as augmentation for antipsychotic treatment

With modulating dopamine as the primary pharmacotherapeutic option to treat schizophrenia, we are left unable to adequately treat at least 30% of our patients, Dr. Christoph Correll told the audience at the 2016 Pacific Psychopharmacology Conference in Vancouver. The evidence for combining dopamine antagonists, whether first- or second-generation antipsychotics, is not favorable according to a meta-analysis he described which is in review for publication. When only high-quality studies were included, which involved 14 trials with 938 subjects, the evidence for combining antipsychotics melted to nothing. Although it makes sense that using two medications with the essentially the same mechanism of action would not be synergistic, many practitioners nevertheless do just that.

Dr. Christoph Correll at the 2016 Pacific Psychopharmacology Conference

Dr. Christoph Correll at the 2016 Pacific Psychopharmacology Conference

Dr. Correll, who is Professor of Psychiatry at Hofstra Northwell School of Medicine and Medical Director of the Recognition and Prevention Program at the Zucker Hillside Hospital in Queens, New York, said that adding agents with a different mechanism of action may be more promising. Topirimate acts to inhibit activity in the glutamate-NMDA receptor complex and is approved as an anticonvulsant. It also counters the weight gain of psychotropic medications by reducing appetite and enhancing insulin sensitivity. He and six coauthors have recently published a meta-analysis of 16 randomized, controlled trials including a total of 934 patients who received topirimate adjunctive to antipsychotic therapy; outcome data included PANSS or BPRS total scores and body weight, and secondary outcomes included positive and negative symptoms and various metabolic measures including waist circumference and serum glucose.

The benefit for augmentation was significant as measured by total PANSS or BPRS for the entire group, and sensitivity analyses showed it held true with a dose of 150 mg per day or less, in first and multi-episode patients, and either with clozapine or non-clozapine antipsychotics. The effect was independently significant for positive and for negative symptoms. Topirimate was associated with a significant reduction in weight with a mean reduction of 2.75 kg; other metabolic measures were unchanged except for significant reduction in serum triglycerides and fasting insulin. Although discontinuation for adverse effects or inefficacy did not differ with topirimate or placebo, notable adverse effects of topirimate included concentration problems and paresthesias.

These studies were all short-term with a mean duration of 11.8 weeks, a problem with many clinical trials in psychiatry  given that schizophrenia is a chronic disorder and patients remain on  medication for months to years. Cognitive problems including word-finding difficulty are a known effect of topirimate, and in an illness in which cognitive impairment is inherent, this could be a major liability. Longer-term effects on cognition, metabolic outcomes and psychosis are needed. Will topirimate be the NMDA-modulating treatment that makes a difference or end up like lamotrigine, abandoned after a brief dalliance?

Reference

Zheng W, Xiang Y-T, Xiang Y-Q, Li X-B, Ungvari GS, Chiu HFK, Correll CU. Efficacy and safety of adjunctive topiramate for schizophrenia: a meta-analysis of randomized controlled trials. Acta Psychiatr Scand. 2016:1–14. Published online 1 Sep 2016. Abstract

Schizophrenia is not a progressive brain disease

DSC_0072 1 (2)Despite Emil Kraepelin’s early characterization of dementia praecox, the disorder or disorders that we now call schizophrenia are not characterized by dementia, or inevitable loss of cognitive ability and function. Dr. Robert B. Zipursky, Professor of Psychiatry and Behavioural Neurosciences at McMaster University in Hamilton, Ontario, said that psychiatrists may share Kraepelin’s impression of a malignant illness because of the clinician’s illusion, which arises from the biased sample of patients that psychiatrists treat, i.e. people with chronic, relapsing illness and multiple co-morbidities who come to hospitals (1). According to Professor Zipursky, who spoke at the 9th Annual Pacific Psychopharmacology Conference in Coquitlam, BC on September 18, 2015, available studies indicate that about 70% of people with first-episode psychosis will achieve remission within a year; he defined remission as having positive symptoms no greater that mild in severity and negative symptoms no greater than moderate in severity.

First-episode psychosis includes patients with various diagnoses including bipolar disorder, schizoaffective disorder, brief psychotic disorder as well as schizophrenia. Patients who achieve functional recovery, however, represent a smaller group, especially in those confirmed to have schizophrenia. In long-term outcome research, 20% or fewer of people with schizophrenia meet criteria for recovery defined as sustained remission of symptoms and success in social relations and competitive employment.
Some psychiatrists have concluded that this long-term functional impairment is due to progressive cognitive deterioration which may occur with untreated or chronic positive psychotic symptoms. A related hypothesis is the “neurotoxicity of psychosis” which posits that persisting psychosis leads to ongoing loss of cerebral tissue as manifested by enlarged ventricles and cortical atrophy on neuroimaging, accompanied by worsening deficits on neuropsychologic testing. Consequently, many clinicians working in first episode psychosis accept that the duration of untreated psychosis is an important determinant of long-term outcome.

While he acknowledged that deficits in grey matter volumes observed with MRI are more prominent in chronic patients, Dr. Zipursky asserted that many factors may contribute to this such as sampling bias; concurrent substance use including cannabis, tobacco and alcohol; lack of physical activity; and chronic antipsychotic therapy. The latter is controversial, but he cited a meta-analysis of longitudinal MRI studies in which change in grey matter volumes was correlated with antipsychotic exposure but not illness duration or severity (2). However, he emphasized that relieving suffering and improving function are the goals of treatment, not specifically increasing cerebral volume, which is affected by various factors mentioned before. Furthermore, Dr. Zipursky showed compelling evidence that following a first episode of schizophrenia, antipsychotic discontinuation is by far the most important cause of relapse.

Duration of untreated psychosis (DUP) has a small correlation with treatment outcome, likely accounting for less than 5% of the variance in clinical outcome measures, and questionable association with cognitive functioning and structural brain measures, according to Dr. Zipursky. He presented evidence that it is a risk marker for poor outcome in schizophrenia as opposed to a causative risk factor. “It’s not certain that it relates to improving outcomes, but it does relate to reducing suffering,” Zipursky said.
He concluded that to improve outcomes and promote functional recovery, antipsychotic medication is crucial but so are psychosocial interventions to manage substance use, educate families, provide adequate housing and income support when needed, and engage patients in vocational rehabilitation and supported employment.

References

Zipursky RB, Reilly TJ, Murray RM. The myth of schizophrenia as a progressive brain disease. Schizophr Bull. 2013;39:1363-1372. Full text

Fusar-Poli P, Smieskova R, Kempton MJ, Ho BC, Andreasen NC, Borgwardt S. Progressive brain changes in schizophrenia related to antipsychotic treatment? A meta-analysis of longitudinal MRI studies. Neurosci Biobehav Rev. 2013;37:1680-1691. Full text

Norclozapine, the metabolite of clozapine, may be more useful than you think

Although psychiatrists know that long-term disability in schizophrenia is related to negative and cognitive symptoms, our treatment goals often focus on positive symptoms. The unfortunate reason is that we lack good treatments for cognitive and behavioral deficits. Many antipsychotics have anticholinergic properties which we know can dull cognition or even cause delirium in sensitive patients, but we accept this risk in exchange for the benefit of eliminating psychosis.

Clozapine is highly anticholinergic but its metabolite, N-desmethylclozapine or norclozapine, has partial cholinergic agonist activity at muscarinic receptors. Although psychopharmacologists have suspected that this property of norclozapine may have cognitive benefits, most psychiatrists focus on optimizing clozapine serum level which is sometimes achieved by blocking clozapine metabolism with cytochrome enzyme inhibitors such as the antidepressant fluvoxamine. This increases the clozapine/norclozapine ratio; some evidence suggests this may reduce the metabolic burden of clozapine therapy (1). However, new evidence suggests that this may come at the price of worse cognitive performance, in particular working memory.

A team of researchers at the Centre for Mental Health and Addictions in Toronto examined the hypothesis that a greater ratio of clozapine to norclozapine would correlate with worse cognitive performance as measured by the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MATRICS battery) (2).  They recruited 30 adults, mean age 38.6 years, on clozapine monotherapy for schizophrenia or schizoaffective disorder whose dose had been unchanged for at least 4 weeks. The subjects had blood taken for clozapine and norclozapine concentrations on the same day that they underwent PANSS rating and the MATRICS battery, which comprises 10 tests in 7 cognitive domains such as verbal learning, visual learning, working memory and processing speed.

In multiple regression analyses, the clozapine/norclozapine ratio was negatively correlated with performance on working memory but not with the other 6 cognitive domains. Working memory performance was not correlated with demographic variables or PANSS score, nor with either clozapine or norclozapine serum concentrations independently of each other.

The investigators suggest that the significance of the clozapine/norclozapine ratio reflects the opposing effects of the two molecules on muscarinic type 1 receptors, given that the cholinergic system is crucial for complex attentional processes as tested by working memory measures. They acknowledge that the MATRICS battery may not be sensitive enough to detect effects on other domains, and also that this is a cross-sectional study that cannot establish causation. Serial measurements in individuals as the clozapine/norclozapine ratio changes would be more conclusive.

References

1. Lu ML, Lane HY, Lin SK, Chen KP, Chang WH. Adjunctive fluvoxamine inhibits clozapine-related weight gain and metabolic disturbances. J Clin Psychiatry. 2004;65:766-771. Abstract

2. Rajji TK, Mulsant BH, Davies S, et al. Prediction of working memory performance in schizophrenia by plasma ratio of clozapine to N-desmethylclozapine. Am J Psychiatry. 2015;172:579-585. Abstract

Supersensitivity psychosis in treatment resistance

Guy Chouinard proposed the concept of dopamine supersensitivity psychosis (DSP) in 1978, a consequence of chronic antagonism of dopamine D-2 receptors which also is posited to cause tardive dyskinesia (1). The proposed mechanism is upregulation of D2 receptors in the basal ganglia, and tardive dyskinesia is itself considered one of the markers of the condition, also characterized by tolerance to increasing doses of antipsychotic. Supersensitivity psychosis patients may therefore represent a subtype of treatment resistance. In this study from Japan, the investigators examined this hypothesis in a group of patients with chronic psychosis (2).

The 147 patients enrolled had treatment-resistant schizophrenia or schizoaffective disorder as defined by failure of at least 2 antipsychotics at a dose equivalent to 600 mg chlorpromazine for 4 weeks. Although specifics of antipsychotic therapy were not provided, none of the patients was on clozapine. Their mean duration of illness was about 23 years. Supersensitivity was diagnosed if a patient met one of 3 criteria, which were adopted from Chouinard:

  • Antipsychotic tolerance indicated by relapse while on medication and failure to improve despite 20% or more increase in dosage
  • Rebound psychosis manifested by swift relapse with reduction or discontinuation of medication; the psychosis may involve new symptoms for a patient
  • Presence of tardive dyskinesia

The investigators found that 106 or 72.1% of the patients met at least one criterion for DSP; 56% had tolerance, 44% had tardive dyskinesia, and 42% had rebound psychosis. The patients were also classified by the presence or absence of deficit syndrome, defined by prominent negative symptoms assessed by standardized rating instruments. Of 55 patients judged to have deficit syndrome, the majority did not meet criteria for DSP; hence, DSP was significantly negatively associated with prominent deficit symptoms.

Although the researchers evaluated the present state of each subject, the main limitation of the study was reliance on chart reviews for the longitudinal course of patients’ illness. Furthermore, relapse of symptoms due to nonadherence could not be reliably distinguished from antipsychotic tolerance. The findings however suggest that supersensitivity psychosis may be an important contributor to treatment resistance, and that investigations using functional imaging and other techniques are warranted to validate the concept of DSP.

References Continue reading

Could grey matter loss in the superior temporal gyrus contribute to treatment resistance?

The DSM 5 abandoned classifying schizophrenia by psychopathology subtype, but the heterogeneity of the disorder still requires explanation. A more pragmatic approach advocated by some researchers is classification according to treatment response: antipsychotic responsive, clozapine responsive, and clozapine non-responsive. Investigators are looking at the biologic correlates of these subtypes, and a group from New Zealand recently examined differences in brain volume. Using a 3-Tesla scanner, they obtained T1-weighted images of the brains of 18 antipsychotic responders, 19 clozapine responders (for whom other antipsychotics failed), 15 clozapine nonresponders, and 20 controls. All subjects were 18 to 45 years old, and patients with neurologic or active addictive disorders were excluded. The clozapine responsive and non-responsive patients had failed to respond to at least two trials of other antipsychotics, and the PANSS was used to assess symptoms.

The groups of patients did not differ by mean age, PANSS scores or illness duration. The groups had some differences in substance use history; the clozapine-resistant patients had more use of hallucinogens, and the antipsychotic responsive group had more use of cannabis, but the groups did not differ in stimulant use history.

Compared with controls, all patient groups had a reduction in whole-brain and white-matter volumes, and the clozapine-resistant group had a significant increase in ventricular volume. The treatment-resistant and clozapine-resistant patients had smaller grey matter volumes compared with controls and antipsychotic-responsive patients. In analysis using voxel-based morphometry, a technique to examine the volume of specific brain regions, the clozapine-resistant patients, compared with controls, showed bilateral grey matter reductions in the superior and middle temporal gyri, ventromedial prefrontal cortex, anterior cingulate gyrus, and postcentral gyrus. The left cerebellum and right occipital cortex also showed grey matter reduction. Compared with controls, the treatment-resistant group had a similar magnitude of grey matter volume reduction which especially affected the right perisylvian region.

Compared with the antipsychotic-responsive group, both clozapine-resistant and clozapine-responsive groups had reduction in grey matter volume with somewhat differing patterns. Only the clozapine-resistant patients had a relative reduction in the left cerebellum and left anterior cingulate gyrus. No differences were seen in comparing the clozapine-resistant and clozapine-responsive groups.

A controversy in the field of neuroimaging of schizophrenia is the role of antipsychotic exposure in cerebral volume loss; previous research has shown conflicting results. In this study, the clozapine-resistant group had a higher mean daily dose of antipsychotic compared with the other groups, but the researchers found no overall correlation between daily dose and grey matter volume. The study did not look at lifetime antipsychotic exposure.

The investigators highlight the finding of prominent volume reduction in the superior temporal gyrus in the clozapine-resistant group, which was seen in a number of prior studies including longitudinal investigations and in first-episode patients. This brain structure is crucial for auditory processing and language, which are highly implicated in schizophrenia; perhaps tissue loss in this region contributes to poor medication response. However, as the researchers state, in this kind of observational study we are unable to draw conclusions about cause and effect.

Anderson VM, Goldstein ME, Kydd RR, Russell BR. Extensive grey matter volume reduction in treatment-resistant schizophrenia. Int J Neuropsychopharmacol. Published online Feb 25, 2015. Abstract