• The treatment of schizophrenic patients who fail to respond to adequate trials of neuroleptics is a major challenge. Clozapine, an atypical antipsychotic drug, has long been of scientific interest, but its clinical development has been delayed because of an associated risk of agranulocytosis. This report describes a multicenter clinical trial to assess clozapine's efficacy in the treatment of patients who are refractory to neuroleptics.DSM-IIIschizophrenics who had failed to respond to at least three different neuroleptics underwent a prospective, single-blind trial of haloperidol (mean dosage, 61 ±14 mg/d) for six weeks. Patients whose condition remained unimproved were then randomly assigned, in a double-blind manner, to clozapine (up to 900 mg/d) or chlorpromazine (up to 1800 mg/d) for six weeks. Two hundred sixty-eight patients were entered in the doubleblind comparison. When a priori criteria were used, 30% of the clozapine-treated patients were categorized as responders compared with 4% of chlorpromazine-treated patients. Clozapine produced significantly greater improvement on the Brief Psychiatric Rating Scale, Clinical Global Impression Scale, and Nurses' Observation Scale for Inpatient Evaluation; this improvement included "negative" as well as positive symptom areas. Although no cases of agranulocytosis occurred during this relatively brief study, in our view, the apparently increased comparative risk requires that the use of clozapine be limited to selected treatment-resistant patients.

Clozapine for the treatment-resistant schizophrenic. A double-blind comparison with chlorpromazine

OBJECTIVE: The purpose of this study was to estimate and compare the effects of anti­psychotics—both the newer ones and the conventional ones—on body weight. METHOD: A comprehensive literature search identified 81 English- and non-English-language articles that included data on weight change in antipsychotic-treated patients. For each agent, a meta-analysis and random effects metaregression estimated the weight change after 10 weeks of treatment at a standard dose. A comprehensive narrative review was also conducted on all articles that did not yield quantitative information but did yield important qualitative information. RESULTS: Placebo was associated with a mean weight reduction of 0.74 kg. Among conventional agents, mean weight change ranged from a reduction of 0.39 kg with molindone to an increase of 3.19 kg with thioridazine. Among newer antipsychotic agents, mean increases were as follows: clozapine, 4.45 kg; olanzapine, 4.15 kg; sertindole, 2.92 kg; risperidone, 2.10 kg; and ziprasidone, 0.04 kg....

https://ajp.psychiatryonline.org/doi/pdf/10.1176/ajp.156.11.1686

Antipsychotic-Induced Weight Gain: A Comprehensive Research Synthesis

http://zaldlab.psy.vanderbilt.edu/resources/Publications/mtt11nbr.pdf

Reconsidering anhedonia in depression: lessons from translational neuroscience.

Brain reserve capacity on symptom onset after brain injury: A formulation and review of evidence for threshold theory.

The discovery of neuroleptic drugs in 1952 provided a new strategy for seeking a biological basis of schizophrenia. This entailed a search for a primary site of neuroleptic action. The Parkinsonian effects caused by neuroleptics suggested that dopamine transmission may be disrupted by these drugs. In 1963 it was proposed that neuroleptics blocked "monoamine receptors" or impeded the release of monoamine metabolites. The neuroleptic concentration in plasma water or cerebrospinal fluid was of the order of 2 nM for haloperidol in clinical therapy. A systematic research was made between 1963 and 1974 for a primary site of neuroleptic action which would be sensitive to 2 nM haloperidol and stereoselective for (+)-butaclamol. Direct evidence that neuroleptics selectively blocked dopamine receptors occurred in 1974 with the finding that nanomolar concentrations of these drugs stereoselectively inhibited the binding of [3H]-dopamine or [3H]-haloperidol. These binding sites, now termed D2 dopamine receptors (which inhibit adenylate cyclase), are blocked by neuroleptics in direct relation to the antipsychotic potencies of the neuroleptics. No such correlation exists for D1 receptors (which stimulate adenylate cyclase). Based on the fact that dopamine-mimetic drugs elicited hallucinations, and that neuroleptics caused rigidity, Van Rossum in 1966 had suggested a hypothesis that dopamine pathways may be overactive in schizophrenia. The D2-selective blockade by all neuroleptics (except the monoamine-depleting reserpine) provided strong support for the dopamine hypothesis. Further support now comes from postmortem data and in vivo positron tomographic data, both of which indicate that the density of D2 receptors are elevated in the schizophrenic brain. The postmortem data indicate a bimodal pattern with half the schizophrenics having striatal D2 densities of 14 pmol/g (control is 13 pmol/g) and the other half having 26 pmol/g. Current positron tomographic data indicate D2 densities of 14 pmol/g in control subjects, but values of 34 pmol/g in drug-naive schizophrenics. Future tests of the dopamine hypothesis of schizophrenia may entail an examination of the amino acid composition and genes for D2 receptors in schizophrenic tissue, an examination of the ability of the D2 receptor to become phosphorylated and to desensitize into the low-affinity state, and an examination of the interaction of D2 receptors with D1 receptors or other neurotransmitters.

Dopamine receptors and the dopamine hypothesis of schizophrenia.

Two hundred and sixteen psychiatric patients (183 men and 33 women) hospitalized in Sct. Hans Hospital were treated with clozapine between 1971-1983. All had been treated previously with one or more neuroleptic(s) and had either failed to respond adequately, or their response was limited by side effects. Eighty-five patients were treated exclusively with clozapine, while the remaining 131 received additional medication, mainly other neuroleptic drugs. The mean clozapine dosage was 317 mg/day (range 50-1200), and the mean duration of treatment was 23/4 years (range 1/12-12). The tolerability to clozapine was determined by an evaluation of haematological changes, pronounced side effects and mortality. One patient treated with clozapine (8 months) and nitrofurantoin (8 days) developed a reversible granulocytopenia. One patient (treated with a combination of drugs) had clinically insignificant depression of the leucocytes and three of segmented granulocytes. Seven had a reduction in thrombocytes. Two patients developed cardiac insufficiency, and four epileptic seizures. None of the patients treated exclusively with clozapine developed neurological side effects. A global estimation of therapeutic effect revealed that clozapine alone or in combination with other neuroleptic drugs was significantly better than previous antipsychotic therapy, although 47-63% of the patients showed no change. It is concluded that clozapine is a potent antipsychotic drug offering particular advantages in the treatment of schizophrenic patients with a pronounced symptomatology and tendency towards developing extrapyramidal side effects. Caution is advised in patients with cardiac insufficiency and epilepsy. There appears to be a slight risk of granulocytopenia, and therefore the present monitoring of WBC should continue in order to prevent this reaction and to obtain more complete information regarding risk of granulocytopenia.

Tolerability and therapeutic effect of clozapine. A retrospective investigation of 216 patients treated with clozapine for up to 12 years.

Behavioral aspects of serotonin-dopamine interaction in the monkey.

• Brain γ-aminobutyric acid (GABA) has been proposed to play a role in the modulation of extrapyramidal motor function. The effects of increasing brain GABA with γ-acetylenic GABA (GAG), a drug that inhibits GABA transaminase, were evaluated in ten patients with stable tardive dyskinesia during a blind placebo-controlled trial. Drug effects during active treatment and two placebo periods were evaluated by scoring randomly sequenced videotapes of tardive dyskinesia and parkinsonian symptoms recorded weekly during a standardized examination. Tardive dyskinesia was significantly reduced, and preexisting parkinsonism increased slightly. The largest decrease in tardive dyskinesia symptoms occurred in patients receiving higher neuroleptic doses, suggesting an interaction between GABA and dopamine. Prolactin values increased but growth hormone values were unchanged. Psychiatric symptoms were also unchanged during GAG treatment.

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=psych&articleId=492445&pdfFileName=archpsyc_37_12_007.pdf

γ-Acetylenic GABA in Tardive Dyskinesia

Bromocriptine and imipramine in endogenous depression. A double-blind controlled trial in out-patients.

In a 12-weeks double-blind study high dosage versus standard dosage haloperidol therapy was evaluated in 23 male, chronic schizophrenic inpatients. The patients were relatively treatment-resistant and, in spite of traditional neuroleptic medication, were characterized by a moderate to severe degree of illness. At the end of the trial the dose of haloperidol in the standard dosage group was 12–36 mg/day (mean 15), in the high dosage group 10–240 mg/day (mean 103). No significant difference in therapeutic effect was found between the two groups as measured by the Brief Psychiatric Rating Scale and global assessment. About half the patients in both groups improved during the trial. A greater incidence of side effects was noticed in the high dosage group than in the standard group, especially in the form of sedation (5 of 12 patients), aggressive episodes (three patients), muscular weakness and tendency to fall (two patients), and epileptic attacks (one patient). The incidence of extrapyramidal phenomena showed fewer differences between the two groups. In addition, the high dosage group showed a temporary rise in serum alkaline phosphatase and serum aspartate-aminotransferase. There was a positive correlation between the dose of haloperidol and serum haloperidol, and between the haloperidol dose of up to 80 mg/day and serum prolactin. At higher doses prolactin response leveled off. Neither serum haloperidol nor serum prolactin showed any correlation to clinical response. It is concluded (1) that very high doses of haloperidol in only a few cases show any therapeutic advantage over haloperidol in standard doses; (2) that high dosage treatment has a higher incidence of side effects; and (3) that the serum concentrations of a given neuroleptic and of prolactin are of very limited value in the monitoring of neuroleptic treatment.

High dosage haloperidol therapy in chronic schizophrenic patients: A double-blind study of clinical response, side effects, serum haloperidol, and serum prolactin

Jes Gerlach

Papers

Tolerability and therapeutic effect of clozapine. A retrospective investigation of 216 patients treated with clozapine for up to 12 years.

Behavioral aspects of serotonin-dopamine interaction in the monkey.

γ-Acetylenic GABA in Tardive Dyskinesia

Bromocriptine and imipramine in endogenous depression. A double-blind controlled trial in out-patients.

High dosage haloperidol therapy in chronic schizophrenic patients: A double-blind study of clinical response, side effects, serum haloperidol, and serum prolactin