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

Dimenhydrinate (Gravol) abuse worsens schizophrenia

We just published a report in the Journal of Clinical Psychopharmacology of a woman who abused dimenhydrinate for years. Only after she had sustained abstinence from this over-the-counter remedy for nausea did her psychosis respond well to treatment. Read the case report.

Case reports of sodium nitroprusside treatment of clozapine-resistant schizophrenia

In a randomized, controlled trial published in 2014, intravenous sodium nitroprusside was shown to be effective in further reducing positive and negative symptoms of schizophrenia in patients taking a number of antipsychotics including chlorpromazine, haloperidol, olanzapine, risperidone and quetiapine. The same researchers based in Brazil and Canada have published two case reports of patients on clozapine who safely received intravenous sodium nitroprusside (1). The patients, both men, were 22 and 33 years old, and they had persistent positive symptoms of psychosis despite receiving clozapine at adequate dose and duration. Serum clozapine levels were not reported.

The men received nitroprusside according to the same protocol published in JAMA Psychiatry: an infusion of 0.5 microgram per kilogram per minute for four hours. In both cases, the improvements in positive and negative symptoms as measured by the Positive and Negative Syndrome Scale became apparent within hours and lasted for days.

The report does not mention cardiovascular parameters, but in a personal communication, the investigators said that at this dose, nitroprusside has little effect on blood pressure in normotensive people despite treatment with antipsychotics that can reduce blood pressure. The two patients did not receive further infusions because of concern about toxicity with repeated doses of nitrous prusside, which transiently produces small amounts cyanide; however, toxicity is rare with doses less than 5 micrograms per kilogram per minute. With infusions lasting more than 24 hours or in patients with renal insufficiency, accumulation of thiocyanate may occur, which can cause delirium (2). The risk of such toxic events appears to be minimal in low-dose nitroprusside treatment in appropriately selected patients.

This treatment has promise for clozapine-resistant schizophrenia, a severe disease with no well-established treatments except possibly electroconvulsive therapy (ECT). Randomized controlled trial in clozapine-resistant schizophrenia, also called ultra-resistant or super-refractory schizophrenia, are warranted.

References

1. Maia-de-Oliveira JP, Belmonte-de-Abreu P, Bressan RA, Cachoeira C, Baker GB, Dursun SM, Hallak JE. Sodium nitroprusside treatment of clozapine-refractory schizophrenia. J Clin Psychopharmacol. 2014;34:761-763.

2. Michel T, Hoffman BB. Treatment of myocardial ischemia and hypertension. In: Brunton L, Chabner B, Knollman B, eds. Goodman & Gilman’s The Pharmacological Basis of Therapeutics. 12th ed. New York, NY: McGraw-Hill Co., 2011 (online version).

Increasing prevalence of schizophrenia in Canada

The burden of schizophrenia for Canadian society is significant. In a review of incidence and prevalence studies published in peer-reviewed journals dating from 1953 through 2006, Dealberto estimated the one-year prevalence of schizophrenia in Canada at 2.5 to 5.6 per 1000. The investigator found that published incidence and prevalence rates have increased during the past 4 decades. Furthermore, the prevalence and incidence in Canada were greater than international median rates, with Canada’s estimated incidence rate situated between the 45th and 100th percentiles of international comparators.

Dealberto explained the relatively high prevalence of schizophrenia in Canada by three possible factors. First, many studies have found that immigrants have an increased incidence of schizophrenia in both the first and second generations. Canada has a high rate of immigration, about twice that of the United States; 20% of Canadians were born in another country. Second, schizophrenia is more common in countries at high latitude, although the cause of this effect is unknown. Third, urban populations have a greater prevalence of schizophrenia, and 80% of Canadians live in cities.

Population-based studies of the prevalence of treatment-resistant schizophrenia in Canada do not exist. Most reports indicate that treatment resistance occurs in about 30% of patients, hence based on Dealberto’s findings, the estimated one-year prevalence of treatment-resistant schizophrenia in Canada is 7.5 to 17 per 10,000.

Given these data, and assuming a continuation of current immigration policy in Canada, governments at federal and provincial levels must plan for and fund the health-care and social-service needs of a growing number of people with this disorder.

Reference

Dealberto MJ. Are the rates of schizophrenia unusually high in Canada? A comparison of Canadian and international data. Psychiatry Res. 2013;209(3):259-265. Abstract

The refractory psychosis ward at Riverview Hospital between 1993 & 2010

Riverview Psychiatric Hospital Coquitlam BC

OBJECTIVES: Patients in British Columbia who have treatment-resistant psychosis may receive care in a publicly funded academic program where each patient undergoes a multidisciplinary diagnostic evaluation. We describe this assessment process and present findings on a series of patients including a large number with treatment-resistant schizoaffective (SZA) disorder.

METHOD: All patients admitted to the refractory psychosis ward at Riverview Hospital between 1993 and 2010 had failed to respond to at least two previous antipsychotic trials. A psychiatrist, social worker, pharmacist, nurse, general physician, and neuropsychologist evaluated each patient. All available summaries of previous psychiatric admissions were reviewed, and medical, pharmacological, social and behavioural histories were recorded. All information was presented at a case conference and a DSM-IV multiaxial diagnosis reflected agreement between at least two psychiatrists and a psychologist. Symptom ratings included the Positive and Negative Syndrome Scale, the Global Assessment of Functioning, and the Clinical Global Impression-Severity scale.

FINDINGS: Of the 642 patients who were admitted, 92 did not complete treatment (died, were transfered or left against advice) or received a diagnosis other than schizophrenia (SZ), SZA or mood disorder (MD). Consensus diagnosis differed from referral diagnosis in 27% of cases. Of 378 patients referred with SZ, the consensus diagnosis was SZ in 78%, SZA in 15%, MD in 2%, and other in 5%. Of the 145 referred with SZA, the consensus diagnosis was SZA in 63%, SZ in 26%, MD in 3%, and other in 2%. Two thirds of the SZA group were bipolar type. People with confirmed MD or SZA tended to be older and had a longer illness duration, and were more likely to be female, noncaucasian, and married. Functioning and symptom severity in the preceding year and at admission were worse in SZ than SZA patients. PANSS positive scores were greater for SZ and SZA than MD, and PANSS negative scores were more severe in SZ than SZA or MD. Prior depressive episodes were very common in MD (98%) and SZA (89%), but 35% of SZ patients also had a previous depressive episode. Lifetime substance use disorder was found in 63% and recent substance abuse in 35% of patients, and these proportions did not differ across diagnoses. At admission, SZA patients were more likely than SZ patients to have been on a mood stabilizer, but the mean number of antipsychotics and total amount (defined daily dose) did not differ.

CONCLUSION: In a series of patients with treatment-resistant psychosis, the most common diagnosis was SZ, but 29% had SZA. SZA patients were frequently misdiagnosed in the community, and compared to SZ patients, tended to have better baseline functioning, lower symptom severity, were older, and had been ill longer.

Brazil: The Use of Nitrous Prusside for Schizophrenia

nitrous prusside, schizophrenia, mental health

In 2013, Drs. Jaime Hallak, Joao Paulo Maia-de-Oliveira and associates in Ribeirao Preto, Brazil, published results from a randomized controlled trial of intravenous nitroprusside in schizophrenia. Two Canadian researchers from the University of Alberta collaborated on the trial. This study was the first to find that sodium nitroprusside, a treatment for hypertensive crises, has a rapid and prolonged effect on both positive and negative symptoms in patients with acute psychosis. The presumed mechanism is enhancement of nitric oxide in the central nervous system, which may modulate the NMDA receptor-cGMP pathway. In normotensive patients, nitroprusside has minimal effect on blood pressure, and cyanide accumulation is a theoretical concern but occurs only after 72 hours or more of continuous infusion. In treating schizophrenia, the infusion dose is 0.5 mg/kg/minute for four hours.

In the initial trial published in JAMA Psychiatry, Hallak’s team used the Brief Psychiatric Rating Scale and the negative subscale of the Positive and Negative Syndrome Scale (PANSS) as outcome measures. A significant effect on certain components occurred within the first two to three hours of treatment, and improvement endured for four weeks. All the patients were also receiving an antipsychotic other than clozapine.

I met with Jaime, Joao Paulo and their team at the University of Sao Paulo Hospital in Ribeirao Preto and was able to observe a treatment. When I first met the patient, whose infusion had begun 10 minutes before, she appeared anxious and tended to avoid eye contact. When I returned 90 minutes later, she was engaged in an art activity and was eager to show me what she had created. She smiled broadly and even tested her English vocabulary a little. The researchers said that they often see an improvement in the patients’ affect over the course of the infusion, and they are trying to find ways to measure this more objectively. Although data are still limited, the effect in treatment-resistant patients tends to be more delayed.

Further studies of nitrous prusside in Ribeiroa Preto are underway, including for treatment-resistant patients, some on clozapine, and on neurophysiologic effects as detected with fMRI and event-related potential. Because the benefits of the treatment begin to wane after four weeks, they are planning a controlled trial of weekly nitrous prusside infusions for four weeks followed by 60 days of observation.
Reference
Hallak JEC, Maia-de-Oliveira JP, Abroa J, et al. Rapid Improvement of Acute Schizophrenia Symptoms After Intravenous Sodium Nitroprusside: A Randomized, Double-blind, Placebo-Controlled Trial. JAMA Psychiatry. 2013;70:668-676. Abstract
Photo: Left to right: Dr. Jaime Hallak, Dr. Joao Paolo Maia-de-Oliveira, Juliana Almeida (audiologist), their patient and her mother

Estradiol for treatment-resistant schizophrenia

Researchers from Australia have conducted the first controlled trial of estrogen in premenopausal women with treatment-resistant psychosis (1). They recruited 183 women with schizophrenia or schizoaffective disorder who were not pregnant, lactating, or postmenopausal; and who had no history of breast cancer, endocrine disorders, migraine with aura, or thromboembolism. Patients with acute mania were excluded. Patients were randomly assigned to receive either transdermal estradiol 100 mcg daily, transdermal estradiol 200 mcg daily, or placebo patch. The primary outcome measure during the 56-day trial was the Positive and Negative Syndrome Scale (PANSS). Other measures included the Montgomery-Asberg Depression Rating Scale (MADRS), the Repeatable Battery of Neuropsychological Status, adverse-effects monitoring, and serum estradiol concentration at the baseline and during treatment.

The baseline demographic, illness, and treatment characteristics did not differ among the placebo, 100 mcg-estradiol, and 200-mcg estradiol groups. Most subjects were outpatients, and the three groups had mean PANSS total scores of 72-75. Compared with the placebo group, both treatment groups had significant increases in serum estradiol concentration; and greater decreases in mean PANSS positive, general, and total scores. The effect size for positive symptoms, however, was 0.0 for the 100 mcg group and 0.44 for the 200 mcg group, which reflected a mean 3.3-point reduction in PANSS-positive score with the higher dose. No significant treatment effect was found for negative symptoms or cognition. The only significant adverse effect was an increase of irregular menses in the 200 mcg group compared with the placebo group.

The investigators acknowledge that this trial was short-term and that the risks of thromboembolism and endometrial carcinoma may accumulate during longer-duration therapy. Raloxifene, a selective estrogen receptor modulator, entails a lower risk of these adverse effects. In 2011, investigators from Spain reported on a randomized trial of 16 postmenopausal women who had significant mean reduction of positive, negative, and general symptoms compared with a comparable placebo group (2). Case reports exist of raloxifene use in premenopausal women with treatment-resistant schizophrenia (3,4), but controlled trials in this population have not been published.

References

1. Kulkarni J, Gavrilidis E, Wang W. Estradiol for treatment-resistant schizophrenia: a large-scale randomized-controlled trial in women of child-bearing age. Molecular Psychiatry. Published online 15 Apr 2014. Abstract

2. Usall J, Huerta-Ramos E, et al. Raloxifene as an adjunctive treatment for postmenopausal women with schizophrenia: a double-blind, randomized, placebo-controlled trial. J Clin Psychiatry. 2011;72(11):1552-1557. Abstract

3. Raveendranathan D, Shivakumar V, Jayaram N, Rao NP, Venkatasubramanian G. Beneficial effects of add-on raloxifene in schizophrenia. Arch Womens Ment Health. 2012;15(2):147-148. Abstract

4. Shivakumar V, Venkatasubramanian G. Successful use of adjuvant raloxifene treatment in clozapine-resistant schizophrenia. Indian J Psychiatry. 2012;54(4):394. Full text

A Meta-Analysis of CBT for Medication-Resistant Psychosis

A team of BC psychologists has performed the first meta-analysis of cognitive-behavioral therapy for medication-resistant psychosis. The 16 published studies that met their inclusion criteria comprised 12 trials and 639 individual patients. Medication resistance was defined as inadequate response of positive symptoms to at least one medication at adequate dose and duration, or treatment with clozapine. All the trials entailed assignment to either individual CBT for 10 to 24 sessions, or to a control intervention such as treatment as usual, psychoeducation or befriending. Four trials lacked masked raters. Outcome measures were typically PANSS or BPRS, and most studies had a follow-up assessment 3 to 18 months after completion of treatment. Based on pooled outcome data, effect size was derived with Hedge’s g.

For improving positive symptoms, the effect size of CBT compared to control intervention at the end of treatment was 0.47. At follow-up 3-18 months after treatment, the effect size was 0.41. Among studies with an outcome measurement for general psychopathology, such as depression and anxiety, the effect sizes were 0.52 at treatment end and 0.40 at follow-up. According to the researchers, excluding studies without masked raters did not significantly change the effect sizes.

This meta-analysis yielded a medium effect size for time-limited CBT in medication-treated patients with residual positive symptoms. The results suggest improvement may be maintained beyond a year. These were not necessarily treatment-resistant patients as typically defined, although some were on clozapine. Research on other important outcomes such as hospital admission, psychosocial functioning, and suicide would help determine the place of CBT in managing treatment-resistant psychosis.

Reference

Burns AM, Erickson DH, Brenner CA. Cognitive-behavioral therapy for medication-resistant psychosis: a meta-analytic review. Psychiatr Serv. Published online 1 Apr 2014. Abstract

Did DSM-5 throw out the subtype baby with the bathwater?

Many clinicians have suspected and some evidence indicates that patients with the disorganized subtype of schizophrenia, or hebephrenia, do not respond as well to non-clozapine antipsychotics as do other subtypes. Investigators examined this hypothesis in 93 consecutively admitted schizophrenia patients at one hospital in Brazil. They confirmed the diagnosis with the Structured Clinical Interview for DSM-IV, and classified patients as either paranoid or disorganized subtype based upon the predominance of hallucinations and delusions versus disorganized speech and behavior using relevant PANSS items. Only 8 patients, who had either catatonic or residual schizophrenia, were excluded. Treatment resistance was defined as failure of two different antipsychotics, and these patients were offered either clozapine or “combination therapy.”

The mean age of the patients was about 32 years and 56% were male. The demographic profiles did not differ between the 25 disorganized and the 60 paranoid patients; however, the disorganized patients had significantly earlier age of onset, more severe symptoms, and lower functioning as measured by the Global Assessment of Functioning scale. Among the disorganized cohort, 60% were treatment-resistant compared with 20% of the paranoid cohort (p < 0.001). The clozapine response rate, as measured by at least 40% reduction in the total PANSS score, was greater than 60% in both groups. Although DSM-5 has eliminated subtypes of schizophrenia, this study suggests that the disorganized-paranoid axis may retain prognostic and hence diagnostic significance. Another interpretation is merely that positive symptoms respond better to non-clozapine antipsychotics than do disorganized features, which may respond better to clozapine. The study did not have masked raters and the total number of patients is small, so replication is necessary. The Brazilian researchers nonetheless advocate for clozapine use earlier in the course of treatment for disorganized-type patients. If this were adopted widely, clinical subtyping would likely require a more careful approach to evaluation than is carried out in usual practice, such as the use of standardized rating instruments. Reference Ortiz BB, Araújo Filho GM, Araripe Neto AG, Medeiros D, Bressan RA. Is disorganized schizophrenia a predictor of treatment resistance? Evidence from an observational study. Rev Bras Psiquiatr. 2013;35(4):432-434. Full text

A study of clozapine discontinuation

In what they call the largest study to date of clozapine discontinuation, researchers examined a Veterans Administration cohort in the United States of 320 patients with schizophrenia or schizoaffective disorder, 91% male, who received clozapine. The Brief Psychiatric Rating Scale (BPRS) was used to assess symptoms. During 15 years of follow-up, 57% of patients had at least one discontinuation, which occurred most often between 3 and 6 months after treatment initiation.

Factors associated with an elevated likelihood of discontinuation were:
• African-American race
• Older age
• Lower disability award from the VA
• Smaller reduction in BPRS score

The top three causes of discontinuation were nonadherence (35%), adverse effects (28%), and administrative reasons (19%). The adverse effects related to discontinuation in order of frequency were:
• Hematologic, most often neutropenia
• Nervous system including sedation and seizures
• Cardiovascular including hypotension and tachycardia
• Autonomic including sialorrhea
• Weight gain

Agranulocytosis occurred in 3 patients, whereas lesser cases of granulocytopenia which still eliminated the possibility of rechallenge occurred in 4 patients; 3.3% of discontinuations therefore precluded restarting clozapine. One patient died of agranulocytosis; the only other clozapine-related death was in a patient with adynamic bowel and consequent aspiration.

The investigators looked at outcomes following discontinuation. Among 183 patients who stopped clozapine, only 16% restarted it and about half of those continued it. Among the approximately 170 patients who remained off clozapine and who received at least 3 months treatment with another antipsychotic, the mean BPRS score rose significantly from 39 to 52.

The limitations of the study include its naturalistic design and retrospective method.

The data confirm clinical impression that clozapine trials often do not succeed, and the chief challenges are managing adherence and adverse effects. Patients who can’t tolerate clozapine do poorly. We need more options for treatment-resistant psychosis.

Reference

Davis MC, Fuller MA, Strauss ME, Konicki PE, Jaskiw GE. Discontinuation of clozapine: a 15-year naturalistic retrospective study of 320 patients. Acta Psychiatr Scand. Published online 2 Dec 2013. Abstract