Adverse neurobiological effects of long-term use of neuroleptics: human and animal studies

Neuroleptics have revolutionized the treatment of schizophrenia and other psychoses since the early 1950s. Several adverse neurobiological effects are, however, associated with the long-term use of these agents. This article will review human and animal studies of these adverse effects, and also present some new data. Tardive dyskinesia (TD) is the most widely studied potentially persistent movement disorder resulting from long-term neuroleptic treatment, and several risk factors for TD development have been identified. Although drug-induced parkinsonism (DIP) usually disappears after the offending agent is withdrawn, a small portion of patients may have persistent parkinsonism. It is however, unclear if this is an aging-related effect. Persistent cognitive impairment associated with long-term use of typical neuroleptics has not been well documented. Atypical antipsychotics may produce improvement in cognitive performance in patients with chronic schizophrenia. MRI changes that are secondary to neuroleptics are possible, but have not yet been studied adequately. There is one unconfirmed report of neurofibrillary tangles associated with long-term neuroleptic use. A number of investigators have reported vacuous chewing movements, and neuropathologic changes following prolonged administration of neuroleptics in animals. We discuss the implications of the various reported adverse effects of long-term use of neuroleptics.     

Psychotic exacerbations produced by neuroleptics

Thirteen schizophrenic patients who developed abnormal psychotic behavior as an adverse reaction to a neuroleptic are described. A. Three patients showed a marked increase in the psychopathology during neuroleptic treatment. These episodes were treated by decreasing or discontinuing the neuroleptics. They did not respond to anticholinergic durgs nor did they respond to an increase in dosage, (another side effect previously reported and referred to here) indeed this treatment worsened the situation. B. Ten patients showed a mixed picture of catatonic excitement or inhibition on neuroleptics and several developed hallucinatory episodes. All of these exacerbations were terminated by anticholinergic injections. Other more familiar CNS abnormalities produced by neuroleptics are briefly discussed.     

Risk factors for tardive dyskinesia in a large population of youths and adults.

This study was designed to identify predisposing factors for tardive dyskinesia (TD) in youths and adults within a large, predominantly developmentally disabled and mentally ill population. The findings support previously reported risk factors for TD, including increasing age, use of anticholinergic medication for those over 40 years old, and long duration of neuroleptic exposure for those over 18 years of age. Higher cumulative levels of "typical" neuroleptic dosage decreased the risk for TD for those over 18. Novel findings included the benefit of personality disorder in individuals 18 to 40 years old and the strong risk factor of profound mental retardation in all age groups. These findings reveal further complex interactions to the risk factors for TD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuroleptic dose reduction in older psychotic patients

We conducted a non-randomized, rater-blind study to safely determine the lowest effective neuroleptic dosage in older psychotic patients and to evaluate the clinical, neuropsychological, and psychosocial effects of neuroleptic dosage reduction. Twenty-seven carefully selected patients with schizophrenia and related psychotic disorders over the age of 45 had their dosage tapered by 25% each month to determine their lowest effective dosage. These patients were compared with patients similar in age, gender, and education who were currently off neuroleptics (n = 19) or maintained on neuroleptics (n = 22). All groups were followed for 11 months. Over the follow-up period, 29% of patients in the taper group, 8% of neuroleptic-free patients, and 0% of patients in the maintenance group experienced some increase in psychopathology, although there was no significant change in mean PANSS score in any group, and no patient required hospitalization. Patients in the taper group were maintained on approximately 60% of their original neuroleptic dosage after restabilization. Extrapyramidal symptoms continued to improve over time in the taper group. Neuropsychological testing did not change significantly over time except for those in the taper group who experienced a decrease in memory-retention on the Hopkins Verbal Learning Test and a significant improvement in digit vigilance and Stroop Interference Index. Carefully selected middle-aged and elderly psychotic patients can have their neuroleptic medications reduced without a significant change in psychopathology. Extrapyramidal symptoms may continue to improve gradually over time. The impact on cognition functioning needs further investigation.     

Neuroleptic treatment increases soluble IL-2 receptors and decreases soluble IL-6 receptors in schizophrenia

The cytokines interleukin-2 (IL-2) and interleukin-6 (IL-6) increase during immune activation, they are released from activated astrocytes and microglial cells in the central nervous system (CNS), and they are able to enhance the catecholaminergic neurotransmission. This study focused on the soluble receptors of IL-2 and IL-6 (sIL-2R, sIL-6R) as a part of the regulation system of IL-2 and IL-6. We studied serum levels of sIL-2R in 30 schizophrenic patients not under neuroleptic medication during an acute exacerbation of the disease and reexamined these patients under neuroleptic treatment after clinical improvement. The sIL-6R levels of 39 schizophrenic patients were estimated under the same conditions. The results were compared with the levels of sIL-2R and sIL-6R in 42 healthy controls. No difference was found between the schizophrenic patients before neuroleptic treatment and the healthy controls. During neuroleptic treatment, however, there was a significant increase of sIL-2R levels and a significant decrease of the sIL-6R levels between the pre- and post-conditions. In comparison with healthy controls, the treatment group also showed increased sIL-2R levels and decreased sIL-6R levels. These results suggest that treatment with neuroleptics is associated with increased sIL-2R and decreased sIL-6R. Since sIL-2R bind and inactivate IL-2, whereas sIL-6R form an active complex with IL-6, the increase of sIL-2R and the decrease of sIL-6R together may reflect a functional down regulation of these activating cytokines. This suggests that neuroleptic therapy has a differentiated immunomodulatory effect.     

Low superoxide dismutase activity in schizophrenic patients with tardive dyskinesia

BACKGROUND: Tardive dyskinesia (TD) is a therapy-resistant adverse effect of neuroleptics. Although the exact pathophysiology of TD is unknown, oxygen radicals have been speculated to play a role in TD based on several lines of evidence. Superoxide dismutase (SOD) is a key enzyme which scavenges oxygen radicals. The authors investigated the association between erythrocyte SOD activity and TD. METHODS: Erythrocyte SOD activities were measured, blinded as to the presence or absence of TD. In 30 patients with schizophrenia who had been on typical neuroleptics for more than 10 years. TD severity was independently assessed, using the abnormal involuntary movement scale (AIMS), by two raters. RESULTS: There was a significant decrease in erythrocyte SOD activity in the definite TD group (N = 10) as compared with the no TD (N = 8) and questionable TD (N = 12) groups. Erythrocyte Cu,Zn-SOD activities correlated with AIMS scores. CONCLUSIONS: Patients with TD had low SOD activities as compared to those without TD. As a causal link between SOD activity and TD was not established in this study, larger prospective studies are warranted to determine whether patients with low SOD activity are susceptible to neuroleptic-induced TD.     

Current topics in tardive dyskinesia in Japan

This article reviews current topics in tardive dyskinesia (TD), a movement disorder associated with the prolonged use of neuroleptic agents, especially therapeutic and preventive strategies which have been or are now being studied in Japan. Tardive dyskinesia has become a major problem in the clinical psychiatric field since the early 1970s in Japan, lagging behind Western countries by more than 10 years. The average prevalence rate of TD has been estimated as 7.7% in Japan, while it has been reported in the English literature at around 15 to 20%. Clinical trials of treatments for TD have been or are now being performed in Japan with a number of novel compounds, such as ceruletide, meclofenoxate, and rolipram; however, no effective treatment has yet been established and measures to prevent TD have therefore been emphasized. These include (i) the development of new antipsychotic drugs which are free from TD, (ii) the identification of risk factors from prospective longitudinal studies, and (iii) the investigation of genetic variations that could act as a marker to identify especially vulnerable patients within the whole population of patients who need neuroleptic therapy.     

Akathisia in adults with mental retardation: development of the Akathisia Ratings of Movement Scale (ARMS)

We developed an akathisia rating scale for use with persons who have mental retardation and screened for the occurrence of akathisia in three samples: 66 adults receiving maintenance neuroleptic treatment, 20 adults not receiving neuroleptics, and 8 adults undergoing neuroleptic dose reduction. The scale had an acceptable level of interrater reliability and validly measured group differences related to neuroleptic treatment status. Using an empirically derived cut-off-score, we estimated the prevalence rate for akathisia to be 5% in neuroleptic-free subjects, 17% in neuroleptic-maintenance subjects, and 25% in neuroleptic-reduction subjects. Akathisia, dyskinesia, and stereotypy manifested as qualitatively different movement topograhies. The occurrence of dyskinesia stereotyped movement disorder was associated significantly with an increased occurrence of akathisia.     

The changing effector pattern of tardive dyskinesia during the course of neuroleptic withdrawal.

Tardive dyskinesia (TD) is a movement disorder that can be expressed at various body effector points, including the face, neck, arms, fingers, legs, and torso. In this prospective longitudinal study researchers examined whether the effector pattern of TD changed during the course of neuroleptic medication withdrawal in adults with mental retardation. Results indicated that the effector pattern of TD changed over the course of neuroleptic withdrawal. Peak dyskinesia was associated with the involvement of more body areas relative to baseline. Although dyskinesia decreased at follow-up and fewer body areas showed signs of dyskinesia, there were still differences in the effector pattern of dyskinesia relative to baseline at periods of 1 to 2 years following neuroleptic withdrawal. These findings suggest that TD is a dynamic disorder associated with changes in both severity and effector pattern over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intermittent neuroleptic treatment and risk for tardive dyskinesia: Cura?ao Extrapyramidal Syndromes Study III

OBJECTIVE: The authors examined the association between three lifetime medication variables (cumulative amount of neuroleptics, number of interruptions in neuroleptic treatment, cumulative amount of anticholinergics) and the occurrence and severity of tardive dyskinesia. METHOD: The study was conducted in the only psychiatric hospital of a well-defined catchment area (the Netherlands Antilles). For all patients who had a history of taking neuroleptics for at least 3 months and were currently using neuroleptics (N = 133, mean age = 51.5 years), the presence and severity of tardive dyskinesia were measured with the Abnormal Involuntary Movement Scale. RESULTS: Of the three lifetime medication variables, only the number of neuroleptic interruptions was significantly related to tardive dyskinesia. The risk of tardive dyskinesia was three times as great for patients with more than two neuroleptic interruptions as for patients with two or fewer interruptions. CONCLUSIONS: This finding supports the schizophrenia protocol of long-term neuroleptic treatment rather than targeted or intermittent neuroleptic treatment.     

Blood biogenic amines during clozapine treatment of early-onset schizophrenia

The aims of this investigation were to evaluate long-term and short-term effects of clozapine-treatment on plasma biogenic amines and psychopathology measures in adolescents with schizophrenia (DSM-III-R criteria). The long-term study was conducted in a study sample of 40 young patients (age 14-22 years) following a mean of 3.4 years of neuroleptic treatment. During the study, 20 patients received clozapine, and the other 20 patients were treated with standard neuroleptic medications. At the beginning of the open clinical trials, the patients had already been receiving clozapine treatment for 24 +/- 15 months. Assessment of the biochemical and psychopathological measures was performed on six occasions at consecutive 6-week intervals during maintenance treatment with clozapine or conventional neuroleptics. Blood levels of serotonin, 3-methoxy-4-hydroxy-phenylglycol (MHPG), norepinephrine, and epinephrine were significantly higher in clozapine-treated patients than in conventionally treated patients. During long-term treatment, higher serotonin levels were associated with significantly fewer negative symptoms of schizophrenia, whereas higher MHPG levels were correlated with less depression. The short-term effects of clozapine were assessed in a second and independent study sample. After failing on conventional neuroleptics in clinical trials lasting a mean of 1.6 years, 15 inpatients (aged 11-20 years) received clozapine. Weekly ratings of psychopathological symptoms using standard rating scales were performed in parallel to blood samplings for measurements of biogenic amines and serum levels of clozapine. These measures were obtained for 6 weeks during conventional neuroleptic treatment and for 6 weeks during the open-label clozapine trial. Serum levels of serotonin and plasma norepinephrine levels were significantly higher during treatment with clozapine than during pretreatment with typical neuroleptics. A comparison of plasma epinephrine levels in responders (n = 7) and nonresponders (n = 8) to clozapine revealed that response to clozapine can be predicted by epinephrine levels prior to initiation of treatment with clozapine (responders ranging from 32.2 to 90.3 pg/ml; nonresponders ranging from 92.5 to 473.5 pg/ml). Additionally, subjects who responded to clozapine showed increased mean plasma concentrations of MHPG and epinephrine during treatment with this drug in comparison to the levels measured during pretreatment with typical neuroleptic medication. Nonresponders to clozapine failed to show this increase. Finally, in responders to clozapine a negative linear relationship between negative symptoms of schizophrenia and the concentrations of plasma norepinephrine and serum serotonin were observed. In conclusion, our results demonstrate that plasma epinephrine levels prior to initiation of clozapine therapy predict response to this atypical neuroleptic. Our findings derived from short-term and maintenance treatment with clozapine suggest involvement of norepinephrine, epinephrine and serotonin in the therapeutic actions of the atypical neuroleptic clozapine.     

Association of plasma homovanillic acid with behavioral symptoms in patients diagnosed with dementia: a preliminary report

Neuroleptic treatment of psychotic symptoms or agitated behavior in elderly patients diagnosed with dementia is associated with reduced efficacy and increased rates of neuroleptic-induced parkinsonism in comparison to younger patients with schizophrenia. We report the first study to examine the relationship between an in vivo measure of dopaminergic function, plasma homovanillic acid (pHVA), and ratings of psychosis, agitation, and parkinsonism before and after neuroleptic treatment in dementia patients. Pretreatment pHVA was significantly correlated with parkinsonian rigidity, with a trend observed with agitation and hostility. Though mean pHVA did not change during perphenazine treatment, intraindividual change in pHVA at day 15 was correlated with improvement in hostility, with a similar trend for improvement in agitation. These preliminary findings are consistent with reports associating dopaminergic function with agitated, but not psychotic, symptoms in patients diagnosed with dementia, and with a reduced responsivity of dopaminergic systems to neuroleptic treatment in these patients.     

Correlated changes in symptoms and neurotransmitter indices during maintenance treatment with clozapine or conventional neuroleptics in adolescents and young adults with schizophrenia

A study of 40 young patients (age 14-22 years) with DSM-III-R schizophrenia (without substance abuse) was conducted following a mean of 3.4 years of neuroleptic treatment. After failing on conventional agents in clinical trials lasting a mean of 2 years, 20 patients were prospectively maintained on open-label clozapine (mean 324 mg daily), and another 20 patients continued on typical neuroleptics (mean 465 mg chlorpromazine-equivalents daily). Patients were then sampled for biochemical measures and assessed for psychopathology (Brief Psychiatric Rating Scale, Scales for the Assessment of Positive/ Negative Symptoms) on six occasions at consecutive 6-week intervals-during maintenance treatment on clozapine or conventional neuroleptics. There were 22-fold interindividual differences in clozapine levels and also high intraindividual differences over time. Maintenance dosage was linearly related to plasma levels of clozapine and its metabolites. Prolactin levels were elevated with typical neuroleptics but not clozapine. Blood levels of serotonin, methoxyhydroxyphenylglycol (MHPG), norepinephrine, and epinephrine (but not dopamine) were significantly higher in clozapine-treated patients than in conventionally treated patients. Higher serotonin levels were associated with significantly fewer negative symptoms, whereas higher MHPG levels were correlated with less depression. These findings suggest involvement of norepinephrine and serotonin in the pathophysiology of schizophrenia (with depression associated with lower MHPG levels and negative symptoms associated with lower serotonin levels) and in the therapeutic actions of clozapine. Speculatively, a treatment strategy of targeting specific neurotransmitter systems might be based on the presence of specific symptoms in adolescents and young adults with schizophrenia.     

Drugs inducing or aggravating parkinsonism: a review

Drug-induced parkinsonism (DIP) is frequent. The list of drugs able to induce parkinsonism is long and probably incomplete, because new drugs, with previously unknown antidopaminergic activity, are constantly being added. Not all the drugs have the same potency for inducing parkinsonism. We classify these drugs in three groups: (1) drugs with obvious antidopaminergic activity which regularly induce parkinsonism; (2) drugs able to induce parkinsonism in particular individuals and (3) drugs which may aggravate Parkinson's disease treated with levodopa. The reports of isolated cases of parkinsonism induced by widely-used drugs (drugs in group 2) may be the result of either an idiosyncratic side effect or a misdiagnosis of parkinsonism. The antidopaminergic activity of the drugs of this group is weak and not sufficiently demonstrated. Maybe, in these cases, the blockage of other neurotransmitters different from dopamine plays a role in the induction of parkinsonism. Probably, the number of patients with DIP is higher than reported or detected, because many patients suffer from weak symptoms that quickly disappear after drug withdrawal. One of the main points of interest is knowing the list, because all these drugs, specially those of group 1, should be avoided or used with caution in the treatment of some common symptomatic problems in patients with Parkinson's disease, such as depression, arterial hypertension, diabetes mellitus and cardiac disorders. The precautions should extent to other populations especially susceptible to suffer from DIP, such as the elderly or patients with other neurodegenerative disorders, such as Alzheimer's disease.     

Parital cutaneous necrosis of the abdominal wall after cesarean section

OBJECTIVE: The assess the incidence of tardive dyskinesia (TD) in a sample of adolescents treated with neuroleptic medication and to identify the presence of any risk factors for TD within the affected group. METHOD: A retrospective chart review was conducted for 40 cases. The Abnormal Involuntary Movement Scale (AIMS) was used to measure side effects from medication at 6-month intervals over 2 years. Drug exposure was converted to chlorpromazine (CPZ) equivalent and the presence of risk factory for TD, such as a diagnosis of affective disorder, medication noncompliance, early age of illness onset, and concomitant antiparkinsonian medication, was also noted. RESULTS: Of the 40 cases reviewed, 2 patients (5%) met diagnostic criteria for TD, and another 5 patients (12.5%) showed symptoms of TD. CONCLUSIONS: TD is a serious risk at any age. Medication noncompliance, early age of illness onset, and concomitant use of antiparkinsonian medication may increase susceptibility to TD and should be carefully monitored.     

New strategies for old problems: tardive dyskinesia (TD). Review and report on severe TD cases treated with clozapine, with 12, 8 and 5 years of video follow-up

Tardive dyskinesia (TD) is the most feared and troublesome extrapyramidal side-effect of prolonged neuroleptic (NL) treatment. We present a review of TD. Its pathophysiology remains elusive, although extrapyramidal symptoms (EPS) increase the liability for TD. Nowadays, therefore, avoidance of all EPS remains the best preventive strategy, as it is not possible to predict which liable patients will develop TD, or of what type or severity. TD frequently includes dystonic features, and is more disabling when these dystonias are present. Clozapine (CLZ) has been reported to be effective in suppressing nearly 60% of TD syndromes, specially those with dystonic features. Based on the few reports in the literature on CLZ and TD by the early 1980s, we started to videotape the first severe TD patient treated with CLZ in 1984. We present the first three case reports of severe TD, with prominent disabling dystonic features, treated with CLZ and videotaped since pretreatment and then periodically for 12, 8 and 5 years of follow-up, respectively. The patients' current diagnosis, gender and age are: Case 1, DSM-IV Schizophrenia Residual Type, male, 39 years; Case 2, DSM-IV Polysubstance Related Disorder, Borderline Personality Disorder, female, 28 years; Case 3, DSM-IV Schizoaffective Disorder, male, 40 years. Two of them presented with a recurrence of TD because of CLZ interruption within the first 2 months of treatment, with no further breakthrough to date. The first two cases have complete remission of TD; the third case is still improving after 5 years of CLZ treatment, with only minor dystonic features persisting that constitute no impairment for work or daily routines at present. All patients, independent of their psychiatric primary diagnosis, have shown significant and progressive improvement in both motor and psychosocial aspects. None of them has been rehospitalized. Long-term treatment and follow-up is required to avoid TD recurrence and to assure full assessment of treatment effectiveness. Ideally, periodic video recording with standardized examination is advisable for long-term follow-up and outcome assessment. At present, CLZ could be regarded as the drug of choice for patients with TD, specially for those with disabling and or dystonic features and who require ongoing NL therapy. The use of novel antipsychotic agents for TD treatment and prevention, with their low EPS liability, is promising, but has yet to be tested.     

Case study: worsening Tourette's disorder or withdrawal dystonia?

This case report focuses on withdrawal dystonia, a movement disorder associated with neuroleptics. Its occurrence in a patient with Tourette's disorder complicated the clinical picture. A misinterpretation of the symptoms led to ineffective management of the movement disorder. The presence of increased blinking with facial pain, dystonic movements, and other facial movements at each neuroleptic dose reduction pointed toward withdrawal dystonia rather than toward a worsening of Tourette's disorder. Implications for diagnosis and treatment are discussed.     

A postmortem study of frontal cortical dopamine D1 receptors in schizophrenics, psychiatric controls, and normal controls

We tested the hypothesis that aberrant dopaminergic innervation in frontal and cingulate cortices of schizophrenic patients might be revealed by examining dopamine D1 receptor density in these brain regions. A quantitative autoradiographic assay with [3H]-SCH 23390 was performed with samples from schizophrenic patients, normal controls, neuroleptic-treated controls, and suicides. There was a significant elevation in specific binding of [3H]-SCH 23390 in the intermediate layer of the prefrontal cortex from neuroleptic-treated controls (p = .05). Elevated [3H]-SCH 23390 binding in several layers from prefrontal and cingulate cortex was observed in schizophrenic subjects, although these results did not reach statistical significance. When data from subjects who had received neuroleptics (schizophrenics and neuroleptic controls) were compared to subjects who had not received neuroleptics (normal controls and suicides), there was a significant elevation in receptor density in both the prefrontal (p = .05) and cingulate cortices (p = .03). These data suggest that elevated [3H]-SCH 23390 binding in human prefrontal and cingulate cortices may occur with chronic neuroleptic treatment, although increased receptor density that may exist as a feature of psychotic illnesses cannot be excluded.     

Benzodiazepine receptors in the post-mortem brain of suicide victims and schizophrenic subjects

To examine the role of benzodiazepine (BZ) receptors in suicide and schizophrenia, we determined BZ receptors in post-mortem brain (Brodmann's area 10) obtained from suicide victims, schizophrenic patients, and control subjects using [3H]RO15-1788 as the radioligand. The maximum number of binding sites (Bmax) of BZ receptors in the cortex of suicide victims was significantly higher compared with controls, but this increase was mainly due to those suicide victims who died by violent means and whose Bmax was significantly higher than of those who died by non-violent means or control subjects. In schizophrenic patients, Bmax was not significantly different from that of control subjects. When the schizophrenic subjects were separated into two groups, those on neuroleptics and those off neuroleptics for at least 12 months, however, the mean Bmax of BZ receptors in the prefrontal cortex in post-mortem brain obtained from schizophrenic patients on neuroleptics was significantly lower than Bmax in drug-free schizophrenic patients or normal controls. There were no significant differences among groups in values of the apparent dissociation constant (KD) of [3H]RO15-1788 binding. These results suggest that BZ receptors are up-regulated in the cortex of suicide victims, specifically those who used violent means, and that neuroleptic treatment may result in decreased central BZ receptor binding in the cortex of schizophrenic patients. Thus, the method of suicide and previous exposure to neuroleptics should be considered in the interpretation of data on BZ receptors.