Effects of atypical and typical neuroleptics on anterior cingulate volume in schizophrenia

Schizophrenia Research 80 (2005) 73 – 84 www.elsevier.com/locate/schres

Effects of atypical and typical neuroleptics on anterior cingulate volume in schizophrenia Laurie McCormick a,*, Lawrence Decker a, Peg Nopoulos a, Beng-Choon Ho a, Nancy Andreasen a,b a

b

The University of Iowa, Carver College of Medicine, Department of Psychiatry, W278 GH, University of Iowa Hospitals and Clinics, Mental Health Clinical Research Center, 200 Hawkins Drive, Iowa City, IA, 52242, United States The MIND Institute and the University of New Mexico, 801 University Boulevard SE, Suite 200, Albuquerque, NM, 87106, United States Received 29 March 2005; received in revised form 30 June 2005; accepted 30 June 2005 Available online 15 September 2005

Abstract We have previously found typical neuroleptic exposure to be correlated with an increase in anterior cingulate volume over time in patients with schizophrenia. However, the effect of atypical neuroleptics on anterior cingulate volume and the clinical significance of these changes are not known. To determine if atypicals differ from typicals in their effect on anterior cingulate volume change over time and to assess the clinical significance of such changes, subjects with schizophrenia were compared to normal controls over time. Anterior cingulate volume was delineated with manual traces on magnetic resonance images of the brain in 31 neuroleptic–naı¨ve subjects and 18 normal controls at admission and 2–3 years later. Neuroleptic exposure for each subject was calculated using a dose–year formula. Increased typical neuroleptics exposure over time was correlated to increased anterior cingulate volume over time (r = 0.92, p b 0.001), while increased atypical neuroleptics exposure was correlated to decreased anterior cingulate volume (r = 0.57, p b 0.006). Increased anterior cingulate volume was correlated to greater psychotic symptom improvement (r = 0.78, p b 0.010). Anterior cingulate volume changes over time are correlated differently with atypical versus typical neuroleptic exposure over time. The increase in anterior cingulate volume with typicals is correlated to improved psychotic symptoms over time. D 2005 Elsevier B.V. All rights reserved. Keywords: Schizophrenia; Neuroleptic; Antipsychotic; Anterior cingulate; Morphometry; Symptoms

1. Introduction * Corresponding author. Tel.: +1 319 353 8536; fax: +1 319 384 5532. E-mail addresses: [email protected] (L. McCormick)8 [email protected] (L. Decker)8 [email protected] (P. Nopoulos)8 [email protected] (B.-C. Ho)8 [email protected] (N. Andreasen). 0920-9964/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.schres.2005.06.022

The anterior cingulate cortex (ACC) is an important part of the limbic system that has been implicated as abnormal in both structure and function in mediating negative and positive symptoms of schizophrenia (Ashton et al., 2000; Sigmundsson et al., 2001; Suhara

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et al., 2002; Theberge et al., 2003). Various studies of ACC abnormalities in schizophrenia have shown there to be reduced or abnormal function (Fallgatter et al., 2003; Haznedar et al., 1997; Hempel et al., 2003; Laurens et al., 2003; Mulert et al., 2001), and reduced or abnormal structure (Benes et al., 2001; Chana et al., 2003; Job et al., 2002; Kubicki et al., 2002; Sun et al., 2003; Suzuki et al., 2002; Velakoulis et al., 2002; Yucel et al., 2002). The reduction in ACC volume for subjects with first onset schizophrenia has been shown to become more significant the longer a subject is sick (Benes et al., 2003; Job et al., 2003; Szeszko et al., 1999). The degree of reduced ACC volume has also been shown to be significantly correlated with executive dysfunction Szeszko et al., 2000), impaired attention (Salgado-Pineda et al., 2003), and overall negative symptoms (Sigmundsson et al., 2001; Paillere-Martinot et al., 2001). Similarly, the degree of decreased blood flow in the ACC has been correlated with negative symptoms (Ashton et al., 2000) and an inability to recognize that mistakes are being made (Carter et al., 1997). Alternatively, an increase in blood flow in the ACC has also been correlated with increased psychotic symptoms (Vollenweider et al., 1997). The effects of medication on brain structure have become an important area of research. In a previous study of neuroleptic naı¨ve subjects, we found no difference in ACC volume compared to controls (Crespo-Facorro et al., 2000a). However, in a follow-up study composed of patients with varying lengths of illness, all exposed to only typical neuroleptics, the left ACC was found to be significantly larger in patients compared to controls. Moreover, volume of the ACC was directly related to medication exposure such that greater exposure was related to greater volume (Kopelman et al., in press). These results are similar to several other studies that have shown a significant correlation of typical neuroleptic dose and increased volume of the basal ganglia (Corson et al., 1999; Heitmiller et al., 2004), insula (Pressler et al., 2005) and the planum polare of the superior temporal gyrus (Crespo-Facorro et al., 2004). Atypical neuroleptic dose on the other hand has been shown to correlate significantly with a decrease in basal ganglia volume over time (Frazier et al., 1996; Gur et al., 1998; Heitmiller et al., 2004; Scheepers et al., 2001). It is unclear, however, if

atypical neuroleptics are similarly correlated with a decrease in ACC volume. More importantly, the clinical implications of brain structure changes related to neuroleptic dose must be clarified. A study by Lieberman et al. (2001) suggests that typical neuroleptic exposure is possibly neuroprotective, it associated with smaller ventricular volume at follow-up, and ventricular enlargement is associated with poor outcome. Although the ACC has classically been linked to cognition, there is also a division of this region that has been linked to both negative and positive symptoms (Mayberg et al., 1999; Vollenweider et al., 1997). No study to date has evaluated changes in brain structure due to neuroleptic exposure with symptom changes in schizophrenia over time. This study is designed as a follow-up to recent findings of neuroleptic effect on the ACC and to assess the effects of both typical and atypical neuroleptics, as well as whether these structural changes are related to changes in symptoms. Both of the two previous studies from our lab were cross-sectional observation studies. In the Crespo-Facorro et al. (2000a,b) study, patients were neuroleptic naı¨ve; thus effects of medication were not studied. In the Kopelman et al. (in press) study, many of these same patients had been exposed to only typical neuroleptics; thus the effects of the atypical class were not evaluated. There is no overlap between patients in this study and the study conducted by Kopelman et al. (in press). This study is a longitudinal study that evaluates both classes of neuroleptic medications (typical and atypical). The design of the study also allows for correlation analysis of change in ACC volume to clinical symptom changes (as measured by the scales for negative and positive symptoms) over time.

2. Method 2.1. Subject description at intake Subjects were obtained from the Prospective Longitudinal Study of Schizophrenia and the Mental Health Clinical Research Center (MH-CRC) at the University of Iowa (Flaum et al., 1992). All subjects were defined as first episode by first hospitalization and were neuroleptic naı¨ve (i.e., had never been on neu-

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roleptics in the past), and then were followed over time. We studied 31 neuroleptic naı¨ve subjects diagnosed with schizophrenia (males = 20, females = 11). Controls for the study consisted of 18 healthy subjects (males = 11, females = 7) matched to the patient sample by sex and age. Exclusionary criteria included a positive history of medical, neurological, or psychiatric illness. They could have no first-degree relatives with schizophrenia or other psychotic disorder. Individuals with a history of alcohol and substance abuse were also excluded. These control subjects were also followed over time and participated in follow-up MRI scanning. The mean age of the patient group was 24.8 years (SD = 5.92) for patients and 30.5 (SD = 6.93) for controls. At intake, the mean duration of illness for the patients was 27.4 months (S.D. = 8.5) and 32.5 months (S.D. = 19.3) for the control subjects. All subjects were initially evaluated using a structured interview, the Comprehensive Assessment of Symptoms and History (CASH) (Andreasen et al., 1992), which has well-documented reliability. The diagnosis of schizophrenia was made according to criteria from the DSM-IV (APA, 1994), on the basis of a structured interview, the CASH, and consensus of at least 2 research psychiatrists. All patients were considered bfirst episodeQ as defined by their intake evaluation being their first psychiatric hospitalization. The average follow-up period for subjects was 3 years (range 2 to 5 years). The diagnosis of schizophrenia was confirmed again at the time of their follow-up scan through the Comprehensive Assessment of Symptoms and History-follow Up (CASH-UP) (Andreasen et al., 1992) and another evaluation by at least 2 research psychiatrists. Demographic information for both of the patient groups as well as the control group is shown in Table 2. The demographics and clinical symptoms over time between the three groups were assessed using an analysis of variance (ANOVA) with normal controls and the 2 subject groups as the between-group factor. There was no significant demographic difference between the 2 subject groups (typical and atypical) and controls in terms of age, gender, handedness, education, or parental socioeconomic class. While there was a small, but significant difference between length of time between scans for patients (28.7 months, S.D. = 12.1) and controls (39.9 months,

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S.D. = 16.8), there was no significant difference between duration between follow-up period between subjects in the atypical (27.5 months, S.D. = 8.7) versus typical (31.7 months, S.D. = 18.2) groups. The study protocol was approved by the Institutional Board of Research at the University of Iowa Hospitals and Clinics and all subjects signed informed consent. 2.2. Medication assessment This study was naturalistic in that all subjects were treated by their own psychiatrists and were not randomized into predetermined treatment groups. Since the Iowa Prospective Longitudinal Study is a naturalistic study design, patients were treated with a variety of different medications from psychiatrists with vastly different practice styles for the past several years throughout the state of Iowa. Complete records of all medications were obtained from medical records and documented in the Psychiatric Symptoms You Currently Have (PSYCH) at the beginning of the study, which is an instrument designed for detailed assessment (Andreasen et al., 1992). A follow-up version of the PSYCH (PSYCH-UP) was then used for follow-up subject assessment (Flaum et al., 1992). Assessments are made every 6 months to provide a time-line of both the dose and start/end dates for every neuroleptic dose change. The detailed medication history obtained over time was used to calculate bdose– yearsQ of exposure to neuroleptics. Exposure was calculated over time (between the intake and followup scan), and weighted for dose (in chlorpromazine equivalents). This calculation was made separately for exposure to atypical and typical neuroleptics (Davis, 1974; Miller et al., 1995; Woods, 2003). Details of the medication classification for the patients as well as the chlorpromazine (CPZ) equivalents for each medication used by our lab are shown in Table 1. (Miller et al., 1995). Based on dose–years at follow-up, patients were initially placed into 3 neuroleptic categories: typical (for those patients treated with only typical neuroleptics, n = 8), atypical (for those patients treated with only atypical neuroleptics, n = 15) or both (for those subjects who had been treated with both classes of medication, n = 8). Subjects in the bbothQ category, were then placed into either the typical or atypical classification based on

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Table 1 Subjects with schizophrenia were divided into 2 groups based on exposure to atypical versus typical neuroleptics based on what they were exposed to most over time

Pure Mixed Risperidone Olanzapine Clozapine Haloperidol Perphenazine Fluphenazine Thiothixene

SZ on Atypicals (n = 22)

SZ on Typicals (n = 9)

15 7 10 11 1

8 1

CPZ equivalents

2 2 50 2 8 2 3

5 2 1 1

Note: SZ = subjects with schizophrenia; CPZ = chlorpromazine equivalents for 100 mg of chlorpromazine. The chlorpromazine equivalence is given for each neuroleptic.

which class of neuroleptic they were exposed to most. The final sample consisted of 22 subjects in the atypical group and 9 subjects in the typical group. For the n = 8 subjects who had received both classes of medication, the timing of the exposure to each class was also assessed. That is, for the n = 7 subjects exposed to both classes of medications but assigned to the atypical group, we documented the medication class that they were exposed to for the 6 months prior to the follow-up scan. All 7 subjects exposed to both classes of medication and assigned to the atypical group were exposed to only atypical neuroleptics in the 6 months prior to the follow-up scan. The same was true for the 1 subjects exposed to both classes of

medication and then assigned to the typical group— that subject had been taking a typical neuroleptic for the 6 months prior to the follow-up scan. The mean atypical dose–years at follow-up for the atypical group was 16.1 (SD = 17.87), while the mean typical dose–years at follow-up for the typical group was 16.6 (SD = 17.70). The specific drugs represented in each group are shown in Table 2. Although many patients had been treated with more than one drug during the follow-up period, this classification was based on the drug they were exposed to most. In the atypical group, n = 11 were primarily treated with olanzapine, n = 10 were primarily exposed to risperidone, n = 1 was primarily treated with clozapine. In the typical group, n = 5 were exposed to haloperidol, n = 2 were exposed to perphenazine, n = 1 was exposed to fluphenazine, n = 1 was exposed to thiothixene. An MRI scan of the brain was obtained when subjects were stable, within just a few days of starting a neuroleptic medication. Thus there was no significant neuroleptic exposure prior to the baseline scans. 2.3. Clinical assessment scales Baseline clinical symptoms were assessed with the Scale for Assessing Negative and Positive Symptoms (SANS and SAPS) (Andreasen, 1990). Scores from the SANS/SAPS are divided into 3 dimensions (positive, negative and disorganized) as described by Arndt et al. (1995). The psychotic symptoms are based on

Table 2 Demographics, clinical and morphological characteristics of healthy controls and subjects with schizophrenia on atypical or typical neuroleptics at baseline Healthy controls (n = 18)

Age (in years) Gender (%) Handedness (%) Educational level Parental socioeconomic status Illness duration (in months) Psychotic symptoms (scale 1–10) Disorganized symptoms (scale 1–15) Negative symptoms (scale 1–20) ACC volume at baseline (cc3)

SZ on atypicals (n = 22)

SZ on typicals (n = 9)

Mean (SD)

Mean (SD)

Mean (SD)

30.5 (6.93) M = 61;F = 39 R = 73; L= 13.5; A= 13.5 14.1 (2.32) 2.9 (0.24) N/A N/A N/A N/A 16.6 (4.77)

23.9 (5.02) M = 71.5; F = 28.5 R = 89; L= 0; A= 11 12.9 (2.24) 3.1 (0.87) 116.2 (164.53) 4.2 (3.58) 3.3 (3.15) 3.4 (4.36) 16.7 (3.64)

27.1 (7.71) M = 62.5; F = 37.5 R = 100 13 (1.60) 3.1 (0.33) 165.2 (263.06) 4.6 (3.21) 5.3 (2.24) 2.56 (6.02) 16.1 (2.85)

F

P

1.70 0.04 2.56 1.33 0.35 0.40 0.06 3.02 0.20 0.08

0.195 0.962 0.088 0.275 0.708 0.534 0.813 0.093 0.661 0.918

Note: SZ = subjects with schizophrenia; M = male, F = female; R = right, L= left; A= ambidextrous; ACC = anterior cingulate cortex; cc3 = cubic centimeters.

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global scores of hallucinations and delusions (scale 1– 10); disorganized symptoms on positive formal thought disorder (disorganized speech), bizarre (disorganized) behavior, and inappropriate affect (scale 1– 15); and negative symptoms based on alogia, affective flattening, avolition, anhedonia (scale 1–20). Clinical symptoms were reassessed with the SANS/SAPS at follow-up approximately 3 years later. The changes in each clinical symptoms over time was calculated as the follow-up scores subtracted by baseline overall and individual clinical symptom scores. Therefore, a positive score indicated an improvement of symptoms while a negative change score indicated a worsening of symptoms. The atypical and typical neuroleptic patient groups did not differ significantly in symptom profiles at baseline or over time. The two patient groups also did not differ on duration of illness or any of the three symptom domains assessed at intake (Table 1). 2.4. MRI acquisition MR scans were obtained for each subject with a standard T1-weighted three-dimensional spoiled gradient recall acquisition sequence on a 1.5T General Electric Signa scanner (GE Medical Systems, Milwaukee, WI) (TE = 5, TR = 24, flip angle = 40 degrees, NEX = 2, FOV = 26, matrix = 256  192, 1.5-mm slice thickness). The two-dimensional PD and T2 sequences were acquired as follows: 3.0 or 4.0 mm thick coronal slices (TE = 36 ms (for PD) and 96 ms (for T2), TR = 3000 ms, NEX = 1, FOV = 26, matrix = 256  192. 192. The in-plane resolution is 1.016  1.016 mm for the three modalities.

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image (Woods, 1992). The data sets were then segmented using the multispectral data and a discriminate analysis method based on automated training class selection (Harris et al., 1999). The tissue-classified image was then used to generate a trianglebased iso-surface using a threshold of 130 representing pure gray matter, which corresponds to the parametric center of the cortex (Magnotta et al., 1999). This triangulated surface was used as the basis for our calculations of volume. 2.6. ROI definition and reliability Manual tracing of the ACC region of interest (ROI) was based primarily on Crespo-Facorro et al. (1999, 2000b) methods. The boundaries of the ACC were defined as the cingulate and para-cingulate gyrus (when present) from just behind the genu of the corpus callosum, to the anterior tip of the inner surface of the corpus callosum genu, to the ventral-most part of the frontal cortex (Fig. 1). The ACC was then traced on alternating serial coronal slices (every 2.0 mm). The sagittal and transaxial slices were also examined to obtain an overall view of the ACC. The deepest point of the callosal sulcus and the most medial point of the dorsal bank of the ACC sulcus constituted the inner and the outer boundary of the ACC in each coronal slice. The primary data collectors were blind to diagnosis and date of scans.

2.5. Image processing MR data were visually assessed for quality and movement artifacts and MR scans were repeated if needed. The scans were then processed on Linux workstations with locally developed BRAINS2 software (Magnotta et al., 2002). The T1-weighted images were spatially normalized and resampled to 1.0 mm3 voxels so that the anterior–posterior axis of the brain was realigned parallel to the ACPC line and the interhemispheric fissure aligned on the other two axes. The T2 and PD-weighted images were aligned to the spatially normalized T1-weighted

Fig. 1. The ACC is delineated on the medial aspect of a T1-brain image of a subject with schizophrenia. Plane B is drawn at the anterior tip of the inner surface of the corpus callosum genu and defines the posterior boundaries of the C-shaped ACC. The outer boundaries of the ACC are drawn to include both the cingulate and paracingulate gyri.

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Inter-rater reliability was performed as a separate data set for this study, which was based on previously traced ACC by experienced raters. The primary data collector (L.D.) had intra-class correlations of 0.92 for the left ACC and 0.89 for the right ACC.

changes (psychotic, disorganized, negative symptoms) were also correlated with change in ACC volume.

3. Results

2.7. Morphological measures 3.1. Change in ACC volume over time

Cortical volume and surface measures were estimated in cubic centimeters (cc’s) separately for left and right sides of the ACC. The change in volume over time was calculated by subtracting baseline volumes from follow-up volumes for each subject and control. Thus, a negative change score indicated a decrease in volume over time, while a positive change score indicated an increase in volume over time. 2.8. Statistical analysis The change in ACC volume was assessed using an ANOVA for normal controls and subjects on either atypical or typical neuroleptics as the between-group factor. Correlation analyses were used to evaluate the relationship between change in ACC volume over time, neuroleptic exposure, and clinical improvement over time. To minimize any effect of outliers, we used a Spearman correlation to account for correlation between the amounts of neuroleptic exposure over time to overall difference in ACC volume change over time. The change in total gray matter was also covaried in this analysis to determine if the effects on volume change were specific to the ACC and not just a global effect. For the typical neuroleptic group, typical dose–year values were correlated with the change in ACC volume. For the atypical neuroleptic group, atypical dose–year values were correlated with the change in ACC volume. Clinical symptom

There was no significant change in ACC volume over time between normal controls and the 2 subject groups (see Table 3). There are large standard deviations across the three groups indicating a tremendous amount of variability in change over time. However, the change in overall ACC volume within patients on atypicals, typicals and controls was normally distributed. With this degree of variability, it stands to reason that the group means are not statistically different. Moreover, the group means do not accurately reflect what factors may be contributing to such high variability. Within the patient sample, the high variability in ACC change over time may be due to he widely different exposure levels to neuroleptics. 3.2. Relationship between change in ACC volume and neuroleptic exposure When we accounted for differing amounts of typical versus atypical neuroleptic exposure over time between the 2 groups, we found a significant difference between the 2 groups. The more atypical neuroleptic the atypical group was exposed to over time, correlated to smaller ACC volume over time (r = 0.57, p b 0.009), while typical neuroleptic exposure in the typical group correlated to a larger ACC volume over time (r = 0.92, p b 0.001; see Table 4). Therefore, subjects in the typical exposure group with the highest exposure to typical neuroleptics had the greatest increase in ACC volume over time. Subjects with greater exposure to the atypical class of medication in the atypical group was correlated to a decreased ACC volume over time. The mean change in ACC volume for both patient groups were very small with large standard deviations, yet

Table 3 ACC volume change (cc3) over time in normal controls and the 2 subject groups on atypical or typical neuroleptics ACC

Right Left Total

Normal controls (n = 18)

SZ on atypicals (n = 22)

SZ on typicals (n = 9)

Mean (SD)

Mean (SD)

Mean (SD)

0.31 (2.58) 0.25 (1.73) 0.07 (1.76)

0.17 (0.76) 0.01 (0.76) 0.16 (1.37)

0.30 (0.47) 0.13 (1.41) 0.17 (1.30)

Note: SZ = subjects with schizophrenia; ACC = anterior cingulate cortex; cc3 = cubic centimeters.

F

p

0.50 0.16 0.18

0.611 0.856 0.835

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the correlation to change in volume over time to drug exposure is highly significant, indicating a wide variance in drug exposure—those subjects receiving the most medication changed the most in ACC volume while those receiving the least medication changed little, if any in ACC volume. For descriptive purposes, the subjects with the most medication exposure in each group (top 50% based on dose–years) were selected for a between group comparison of volume change over time. The average change in ACC volume for the typical group over time was 0.86 cc (5.4% change), while the average change for of the atypical group was 0.54 cc (3.2% change). When we covaried for change in total gray matter with change in ACC volume for the patient groups versus controls, the results were the same suggesting the effect of neuroleptics on brain volume was specific to the ACC and not a global effect. When we compared the bpureQ typical versus atypical neuroleptic groups there was still no significant difference in ACC volume change between the atypical versus typical groups. However, the correlation of atypical dose years and change in ACC volume was even more significant (r = 0.75, p b 0.001). Since many consider risperidone to be similar to typical neuroleptics (especially at higher doses), we also assessed the correlation of ACC volume changes to atypical dose– year exposure of subjects primarily on risperidone (n = 10). This showed that the total amount of risperidone dose–years exposure correlated significantly with ACC volume decrease (r = 0.83, p b 0.011). Thus risperidone is similar to other atypicals in its effect on ACC volume.

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Table 5 Spearman correlations between overall symptom improvementsin subjects with schizophrenia and change in ACC volume (cc3) change over time Symptoms

Psychotic Disorganized Negative

ACC volume changes with atypicals (n = 22)

ACC volume changes with typicals (n = 9)

r

r

p 0.09 0.04 0.05

0.706 0.860 0.822

p 0.80 0.41 0.08

0.010* 0.273 0.847

Note: *significant at 0.05 level (2-tailed); ACC = anterior cingulate cortex; cc3 = cubic centimeters.

schizophrenia on typical neuroletpics, ACC volume change over time was significantly correlated with an improvement of psychotic symptoms (r = 0.80, p b 0.010; see Table 5). This suggests that for those patients treated with a typical neuroleptic, a volume change in the ACC over time was directly related to the degree of clinical improvement in hallucinations and delusions. Specifically, those patients with the greatest increase in ACC volume experienced the greatest clinical improvement in psychosis. Conversely, those patients who had no significant change in ACC volume had the least amount of clinical improvement. The average improvement in psychotic symptoms for this group was 4.6 on a scale from 1–10. Despite the fact that the atypical group had the same degree of clinical improvement as the typical group, there was no correlation between any other clinical symptoms to change in ACC volume with subjects on atypical neuroleptics.

3.3. Relationship between change in ACC volume and symptom improvement

4. Discussion Table 5 shows the correlations between change in ACC volume and the change scores for the three symptom dimensions (positive, negative, disorganized). For subjects with

Table 4 Spearman correlations between cumulative neuroleptic exposure and change in ACC volume (cc3) over time in subjects with schizophrenia ACC

Right Left Total

SZ on atypicals (n = 22)

SZ on typicals (n = 9)

r

p

r

p

0.017* 0.217 0.006*

0.10 0.80 0.92

0.798 0.010* 0.001**

0.50 0.27 0.57

Note: SZ = subjects with schizophrenia; ACC = anterior cingulate cortex; cc3 = cubic centimeters; *significant at 0.05 level (2-tailed); **significant at 0.001 level (2-tailed).

4.1. Change in ACC volume with neuroleptic exposure The effect of medication on the structure of the brain has become an increasingly important area of research. This study confirms and extends our previous work showing that the structure of a specific region of the cortex, the ACC, is directly influenced by exposure to neuroleptics. The current finding shows that exposure to typical neuroleptics is related to increases in volume of the ACC over time while exposure to the atypical class of neuroleptics is associated with a decrease in volume of the ACC over time. The increase in ACC volume with exposure to typical neuroleptic is consistent with the findings from an independent sample by Kopelman et al. (in press).

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However, this is the first study to show that atypical neuroleptics are correlated to a decrease in ACC volume over time. This is the same pattern of findings reported previously in regard to changes over time in the volume of basal ganglia structures (Frazier et al., 1996; Gur et al., 1998; Heitmiller et al., 2004; Scheepers et al., 2001). The similarities of neuroleptic effect on these 2 regions may be due to the fact that the ACC and basal ganglia are both structurally and functionally connected, such that alterations in one may also affect the other (Antonini et al., 2003; Rauch et al., 2000). Both the ACC and basal ganglia receive direct dopaminergic innervation from the ventral tegmental area and the substantia nigra (Letchworth et al., 2000; Williams and GoldmanRakic, 1998). The nucleus accumbens also links the ACC to the mesolimbic dopamine system (Grace et al., 1998; Wang and Pickel, 2002). The ACC within the prefrontal cortex has one of the largest number of extrastriatal D2 receptors (De Keyser et al., 1998; Kessler et al., 1993; Olsson et al., 2004), and has the richest supply of dopaminergic neurons of any cortical area (Gaspar et al., 1989; Williams and Goldman-Rakic, 1993). Both atypical and typical neuroleptics block dopamine with differing affinities at the D2 receptors to reduce psychotic symptoms common to schizophrenia (Joyce et al., 1997; Seeman, 2002). Typical neuroleptics have been hypothesized to improve psychotic symptoms better than atypicals due to stronger binding of D2 receptors (Stahl, 2000). D2 receptor blockade with haloperidol has been shown to decrease activity within the ACC (Stahl, 2001). Atypical neuroleptics on the other hand have been hypothesized to improve negative symptoms better than typicals through weaker D2 binding and their unique ability to block serotonin 2a receptors, which leads to an increase of dopamine in the prefrontal cortex (Moller, 2003; Stahl, 2000). Increased dopamine within the prefrontal cortex has actually been shown to improve negative symptoms (Fink-Jensen, 2000) and increases activity within the ACC (Fletcher et al., 1996; Grasby et al., 1993). Thus the D2 blocking effects of typical and atypical neuroletpics already are known to be quite different at the ACC. The increase in ACC volume with typical neuroleptics replicates the findings of our previous study

by Kopelman et al. (in press), which also showed a significant correlation between typical dose–year exposure and increased ACC volume in male subjects with schizophrenia. The increase in ACC volume with typical neuroleptics may be a compensatory hypertrophy due to upregulation of D2 receptors that is known to occur at the ACC from exposure to typical neuroleptics (Janowsky et al., 1992). Similarly, there is upregulation of NMDA and GABA receptors in the ACC due to the glutamate and GABA inhibiting properties of typical neuroleptics (Spurney et al., 1999; Zink et al., 2004). In a postmortem study by Benes et al. (1997) subjects with schizophrenia exposed to typical neuroleptics had a 25% higher density of vertical axons and enlarged varicosities within the ACC (Chana et al., 2003). Similarly, a postmortem study by Honer et al. (1997) also showed that the only structural difference between patients with schizophrenia and normal controls was that patients exposed to typical neuroleptics had an increased number of glutamatergic axonal afferents in the ACC. The decrease in ACC volume with exposure to atypical neuroleptics is similar to our finding on basal ganglia volume (Heitmiller et al., 2004; Corson et al., 1999. There are no current studies looking at the effect of atypical neuroleptics on D2 receptors as there have been for the typical neuroleptics. However, atypical neuroleptics are known to actually increase dopamine in the prefrontal cortex through lower affinity and occupancy of D2 receptors, and a high degree of occupancy of the serotonergic receptors (Stahl, 2001), which may lead to a down-regulation of the D2 receptors at the ACC with a compensatory volume decrease. The decrease in ACC volume may be due to pruning of malfunctioning circuits in both the ACC and basal ganglia resulting in improved efficiency in this area. The relationship between a higher dose of atypical neuroleptics and smaller ACC volume over time was even more pronounced in the bpureQ atypical group, which suggests a definite effect of atypical neuroleptics on ACC volume. This effect may or may not be a direct mechanism for structural change though. From this current data though, we can speculate that typical neuroleptics probably have a more direct influence on receptors and blood flow to the ACC,

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while atypical neuroleptic effects on the brain may be more indirect. Many studies have suggested that risperidone functions similar to typical neuroleptics at high doses, especially in regards to extrapyramidal side-effects (Kapur et al., 1995). In this study however, risperidone functions like an atypical in regard to doserelated correlations with decreased ACC volume.

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Therefore, at the time, these patients were a representative sample of the patient population as a whole. More importantly, the finding of typical neuroleptic medication being associated with increasing volumes of the ACC over time is a replication of our previous study, Kopelman et al. (in press), which used a completely different data set. 4.4. Conclusions

4.2. Clinical correlation No study to date has directly studied the clinical implications of the effects of neuroleptics on structural changes in the brain. In the current study, there was a significant correlation between improvement in psychotic symptoms and increased ACC volume for subjects receiving typical neuroleptics, suggesting that those subjects with the greatest improvement in psychotic symptoms had the greatest increase in volume of the ACC and greatest amount of typical neuroleptic exposure. This is consistent with results reported from Lieberman et al. (2001) which suggest that treatment with typical neuroleptics and a decrease in symptoms prevents ventricular enlargement, which is associated with better outcomes. There was no significant correlation between clinical symptoms and decreased ACC volume for subjects receiving atypical neuroleptics. This may be due to the fact that clinical improvement with atypical neuroleptics is related to a different mechanism and/ or site of action than that of typical neuroleptics. Indeed the mechanism by which typical neuroleptics change structure is postulated to be more direct whereas the effects of atypical neuroleptics is probably through an indirect mechanism. 4.3. Limitations The limitations of this study include the small sample size, in particular in the typical neuroleptic group. However, this group is difficult to collect in a naturalistic setting. Currently, the vast majority of patients with schizophrenia are treated with atypical neuroleptics. It is important to note that the patients in the current study within the typical neuroleptic group were assessed in the early mid 1990’s when atypical neuroleptics were just being introduced.

There was a significant positive correlation between dose–years exposure to typical neuroleptics and increased ACC volume over time for subjects with schizophrenia. The change in ACC volume with typical neuroleptics is clinically significant in that it correlates to improved psychotic symptoms. Alternatively, dose–years of exposure to atypical neuroleptics significantly correlated to a decrease in ACC volume. This effect was most pronounced in subjects primarily on risperidone, but did not correlate with any clinical improvements. This study emphasizes the importance of considering the class and dose–years of exposure to neuroleptics in morphological assessments of the cortical regions in subjects with schizophrenia who have been exposed to neuroleptics.

5. Uncited references Bartlett et al., 1994 Bouras et al., 2001

Acknowledgements This study was funded by the following grants: MH43271 (P.I.: NCA), MH31593 (P.I.: NCA), MH40856 (P.I.: NCA). The authors would also like to thank the researchers at the MHCRC for helpful comments and suggestions.

References American Psychiatric Association, 1994. Diagnostic and Statistical Manual of Mental Disorders, fourth ed. American Psychiatric Press, Washington, DC. Andreasen, N.C., 1990. Methods for assessing positive and negative symptoms. Mod. Probl. Pharmacopsychiatry 24, 73 – 88.

82

L. McCormick et al. / Schizophrenia Research 80 (2005) 73–84

Andreasen, N.C., Flaum, M., Arndt, S., 1992. The Comprehensive Assessment of Symptoms and History (CASH). An instrument for assessing diagnosis and psychopathology. Arch. Gen. Psychiatry 49 (8), 615 – 623. Antonini, A., Landi, A., Benti, R., Mariani, C., De Notaris, R., Marotta, G., Pezzoli, G., Gaini, S.M., Gerundini, P., 2003. Functional neuroimaging (PET and SPECT) in the selection and assessment of subjects with Parkinson’s disease undergoing deep brain stimulation. J. Neurosurg. Sci. 47 (1), 40 – 46. Arndt, S., Andreasen, N.C., Flaum, M., Miller, D., Nopoulos, P., 1995. A longitudinal study of symptom dimensions in schizophrenia. Prediction and patterns of change. Arch. Gen. Psychiatry 52 (5), 352 – 360. Ashton, L., Barnes, A., Livingston, M., Wyper, D., 2000. Cingulate abnormalities associated with PANSS negative scores in first episode schizophrenia. Behav. Neurol. 12 (1-2), 93 – 101. Bartlett, E.J., Brodie, J.D., Simkowitz, P., Dewey, S.L., Rusinek, H., Wolf, A.P., Fowler, J.S., Volkow, N.D., Smith, G., Wolkin, A., 1994. Effects of haloperidol challenge on regional cerebral glucose utilization in normal human subjects. Am. J. Psychiatry 151 (5), 681 – 686. Benes, F.M., Todtenkopf, M.S., Taylor, J.B., 1997. Differential distribution of tyrosine hydroxylase fibers on small and large neurons in layer II of anterior cingulate cortex of schizophrenic brain. Synapse 25 (1), 80 – 92. Benes, F.M., Vincent, S.L., Todtenkopf, M., 2001. The density of pyramidal and nonpyramidal neurons in anterior cingulate cortex of schizophrenic and bipolar subjects. Biol. Psychiatry 50 (6), 395 – 406. Benes, F.M., Davidson, J., Bird, E.D., 2003. Quantitative cytoarchitectural studies of the cerebral cortex of schizophrenics. Arch. Gen. Psychiatry 43 (1), 31 – 35. Bouras, C., Kovari, E., Hof, P.R., Riederer, B.M., Giannakopoulos, O., 2001. Anterior cingulate cortex pathology in schizophrenia and bipolar disorder. Acta Neuropathol. (Berl) 102 (4), 373 – 379. Carter, C.S., Mintun, M., Nicholas, T., Cohen, J.D., 1997. Anterior cingulate gyrus dysfunction and selective attention deficits in schizophrenia: [15O]H2O PET study during single-trial Stroop task performance. Am. J. Psychiatry 154 (12), 1670 – 1675. Chana, G., Landau, S., Beasley, C., Everall, I.P., Cotter, D., 2003. Two-dimensional assessment of cytoarchitecture in the anterior cingulate cortex in major depressive disorder, bipolar disorder, and schizophrenia: evidence for decreased neuronal soma size and increased density. Biol. Psychiatry 53 (12), 1086 – 1098. Corson, P.W., Nopoulos, P., Miller, D.D., Arndt, S., Andreasen, N.C., 1999. Change in basal ganglia volume over 2 years in subjects with schizophrenia: typical versus atypical neuroleptics. Am. J. Psychiatry 156 (8), 1200 – 1204. Crespo-Facorro, B., Kim, J.J., Andreasen, N.C., O’Leary, D.S., Wiser, A.K., Bailey, J.M., Harris, G., Magnotta, V.A., 1999. Human frontal cortex: an MRI-based parcellation method. NeuroImage 10 (5), 500 – 519. Crespo-Facorro, B., Kim, J., Andreasen, N.C., O’Leary, D.S., Magnotta, V., 2000. Regional frontal abnormalities in schizophrenia: a quantitative gray matter volume and cortical surface size study. Biol. Psychiatry 48 (2), 110 – 119.

Crespo-Facorro, B., Kim, J.J., Andreasen, N.C., Spinks, R., O’Leary, D.S., Bockholt, H.J., Harris, G., Magnotta, V.A., 2000. Cerebral cortex: a topographic segmentation method using magnetic resonance imaging. Psychiatry Res. 100 (2), 97 – 126. Crespo-Facorro, B., Kim, J.J., Chemerinski, E., Magnotta, V., Andreasen, N.C., Nopoulos, P., 2004. Morphometry of the superior temporal plane in schizophrenia: relationship to clinical correlates. J. Neuropsychiatry Clin. Neurosci. 16 (3), 284 – 294. Davis, J.M., 1974. Dose equivalence of the antipsychotic drugs. J. Psychiatr. Res. 11, 65 – 69. De Keyser, J., Claeys, A., De Backer, J.P., Ebinger, G., Roels, F., Vanquelin, G., 1998. Autoradiographic localization of D1 and D2 dopamine receptors in the human brain. Neurosci. Lett. 91 (2), 142 – 147. Fallgatter, A.J., Bartsch, A.J., Zielasek, J., Herrmann, M.J., 2003. Brain electrical dysfunction of the anterior cingulate in schizophrenic subjects. Psychiatry Res. 124 (1), 37 – 48. Fink-Jensen, A., 2000. Novel pharmacological approaches to the treatment of schizophrenia. Dan. Med. Bull. 47 (3), 151 – 167. Flaum, M.A., Andreasen, N.C., Arndt, S., 1992. The Iowa prospective longitudinal study of recent-onset psychoses. Schizophr. Bull. 18 (3), 481 – 490. Fletcher, P.C., Frith, C.D., Grasby, P.M., Friston, K.J., Dolan, R.J., 1996. Local and distributed effects of apomorphine on frontotemporal function in acute unmedicated schizophrenia. J. Neurosci. 16 (21), 7055 – 7062. Frazier, J.A., Giedd, J.N., Kaysen, D., Albus, K., Hamburger, S., Alaghband-Rad, J., Lenane, M.C., 1996. Childhood-onset schizophrenia: brain MRI rescan after 2 years of clozapine maintenance treatment. Am. J. Psychiatry 153 (4), 564 – 566. Gaspar, P., Berger, B., Febvret, A., Vigny, A., Henry, J.P., 1989. Catecholamine innervation of the human cerebral cortex as revealed by comparative immunohistochemistry of tyrosine hydroxylase and dopamine-beta-hydroxylase. J. Comp. Neurol. 279 (2), 249 – 271. Grace, A.A., Moore, H., O’Donnell, P., 1998. The modulation of corticoaccumbens transmission by limbic afferents and dopamine: a model for the pathophysiology of schizophrenia. Adv. Pharmacol. 42, 721 – 724. Grasby, P.M., Friston, K.J., Bench, C.J., Cowen, P.J., Frith, C.D., Liddle, P.F., Frackowiak, R.S., Dolan, R.J., 1993. The effect of the dopamine agonist, apomorphine, on regional cerebral blood flow in normal volunteers. Psychol. Med. 23 (3), 605 – 612. Gur, R.E., Maany, V., Mozley, P.D., Swanson, C., Bilker, W., Gur, R.C., 1998. Subcortical MRI volumes in neuroleptic–naive and treated subjects with schizophrenia. Am. J. Psychiatry 155 (12), 1711 – 1717. Harris, G., Andreasen, N.C., Cizadlo, T., Bailey, J.M., Bockholt, H.J., Magnotta, V.A., Arndt, S., 1999. Improving tissue classification in MRI: a three-dimensional multispectral discriminant analysis method with automated training class selection. J. Comput. Assist. Tomogr. 23 (1), 144 – 154. Haznedar, M.M., Buchsbaum, M.S., Luu, C., Hazlett, E.A., Siegel Jr., B.V., Lohr, J., Wu, J., Haier, R.J., Bunney Jr., W.E., 1997. Decreased anterior cingulate gyrus metabolic rate in schizophrenia. Am. J. Psychiatry 154 (5), 682 – 684.

L. McCormick et al. / Schizophrenia Research 80 (2005) 73–84 Heitmiller, D.R., Nopoulos, P.C., Andreasen, N.C., 2004. Changes in caudate volume after exposure to atypical neuroleptics in subjects with schizophrenia may be sex-dependent. Schizophr. Res. 66 (2–3), 137 – 142. Hempel, A., Hempel, E., Schonknecht, P., Stippich, C., Schroder, J., 2003. Impairment in basal limbic function in schizophrenia during affect recognition. Psychiatry Res. 122 (2), 115 – 124. Honer, W.G., Falkai, P., Young, C., Wang, T., Xie, J., Bonner, J., Hu, L., Boulianne, G.L., Luo, Z., Trimble, W.S., 1997. Cingulate cortex synaptic terminal proteins and neural cell adhesion molecule in schizophrenia. Neuroscience 78 (1), 99 – 110. Janowsky, A., Neve, K.A., Kinzie, J.M., Taylor, B., de Paulis, T., Belknap, J.K., 1992. Extrastriatal dopamine D2 receptors: distribution, pharmacological characterization and region-specific regulation by clozapine. J. Pharmacol. Exp. Ther. 261 (3), 1282 – 1290. Job, D.E., Whalley, H.C., McConnell, S., Glabus, M., Johnstone, E.C., Lawrie, S.M., 2002. Structural grey matter differences between first-episode schizophrenics and normal controls using voxel-based morphometry. NeuroImage 17 (2), 880 – 889. Job, D.E., Whalley, H.C., McConnell, S., Glabus, M., Johnstone, E.C., Lawrie, S.M., 2003. Voxel-based morphometry of grey matter densities in subjects at high risk of schizophrenia. Schizophr. Res. 64 (1), 1 – 13. Joyce, J.N., Goldsmith, S.G., Gurevich, E.V., 1997. Limbic circuits and monoamine receptors: dissecting the effects of antipsychotics from disease processes. J. Psychiatr. Res. 31 (2), 197 – 217. Kapur, S., Remington, G., Zipursky, R.B., Wilson, A.A., Houle, S., 1995. The D2 dopamine receptor occupancy of risperidone and its relationship to extrapyramidal symptoms: a PET study. Life Sci. 57 (10), PL103 – PL107. Kessler, R.M., Whetsell, W.O., Ansari, M.S., Votaw, J.R., de Paulis, T., Clanton, J.A., Schmidt, D.E., Mason, N.S., Manning, R.G., 1993. Identification of extrastrital dopamine D2 receptors in post mortem human brain with [125I]epidepride. Brain Res. 609 (1–2), 237 – 243. Kopelman, A., Ziebell, S., Spinks, R., Andreasen, N.C., Nopoulos, P., (in press). Morphology of the anterior cingulate in subjects with schizophrenia: relationship to typical neuroleptic exposure. Am. J. Psychiatry. Kubicki, M., Shenton, M.E., Salisbury, D.F., Hirayasu, Y., Kasai, K., Kikinis, R., Jolesz, F.A., McCarley, R.W., 2002. Voxelbased morphometric analysis of gray matter in first episode schizophrenia. NeuroImage 17 (4), 1711 – 1719. Laurens, K.R., Ngan, E.T.C., Bates, A.T., Kiehl, K.A., Liddle, P.F., 2003. Rostral anterior cingulate cortex dysfunction during error processing in schizophrenia. Brain 126 (Pt 3), 610 – 622. Letchworth, S.R., Smith, H.R., Porrino, L.J., Bennett, B.A., Davies, H.M., Sexton, T., Childers, S.R., 2000. Characterization of a tropane radioligand, [(3)H]2beta-propanoyl-3beta(4-tolyl) tropane ([(3)H]PTT), for dopamine transport sites in rat brain. J. Pharmacol. Exp. Ther. 293 (2), 686 – 696. Lieberman, J., Chakos, M., Wu, H., Alvir, J., Hoffman, E., Robinson, D., Bilder, R., 2001. Longitudinal study of brain morphology in first episode schizophrenia. Biol. Psychiatry 49 (6), 487 – 499.

83

Magnotta, V.A., Heckel, D., Andreasen, N.C., Cizadlo, T., Corson, P.W., Ehrhardt, J.C., Yuh, W.T., 1999. Measurement of brain structures with artificial neural networks: two- and three-dimensional applications. Radiology 211 (3), 781 – 790. Magnotta, V.A., Harris, G., Andreasen, N.C., O’Leary, D.S., Yuh, W.T., Heckel, D., 2002. Structural MR image processing using the BRAINS2 toolbox. Comput. Med. Imaging Graph. 26 (4), 251 – 264. Mayberg, H.S., Liotti, M., Brannan, S.K., McGinnis, S., Mahurin, R.K., Jerabek, P.A., Silva, J.A., Tekell, J.L., Martin, C.C., Lancaster, J.L., Fox, P.T., 1999. Reciprocal limbic–cortical function and negative mood: converging PET findings in depression and normal sadness. Am. J. Psychiatry 156 (5), 675 – 682. Miller, D.D., Flaum, M., Nopoulos, P., Ardnt, S., Andreasen, N.C., 1995. The concept of dose years: a reliable method for calculating lifetime psychotropic drug exposure. Schizophr. Res. 15 (1–2), 159. Moller, H.J., 2003. Management of the negative symptoms of schizophrenia: new treatment options. CNS Drugs 17 (11), 793 – 823. Mulert, C., Gallinat, J., Pascual-Marqui, R., Dorn, H., Frick, K., Schlattmann, P., Mientus, S., Herrmann, W.M., Winterer, G., 2001. Reduced event-related current density in the anterior cingulate cortex in schizophrenia. NeuroImage 13 (4), 589 – 600. Olsson, H., Halldin, C., Farde, L., 2004. Differentiation of extrastriatal dopamine D2 receptor density an affinity in the human brain using PET. NeuroImage 22 (2), 794 – 803. Paillere-Martinot, M., Caclin, A., Artiges, E., Poline, J.B., Joliot, M., Mallet, L., Recasens, C., Attar-Levy, D., Martinot, J.L., 2001. Cerebral gray and white matter reductions and clinical correlates in subjects with early onset schizophrenia. Schizophr. Res. 50 (1-2), 19 – 26. Pressler, M., Nopoulos, P., Ho, B.C., Andreasen, N.C., 2005. Insular cortex abnormalities in schizophrenia: relationship to symptoms and typical neuroleptic exposure. Biol. Psychiatry 57 (4), 394 – 398. Rauch, S.L., Kim, H., Makris, N., Cosgrove, G.R., Cassem, E.H., Savage, C.R, Price, B.H., Nierenberg, A.A., Shera, D., Baer, L., Buchbinder, B., Caviness Jr., V.S., Jenike, M.A., Kennedy, D.N., 2000. Volume reduction in the caudate nucleus following stereotactic placement of lesions in the anterior cingulate cortex in humans: a morphometric magnetic resonance imaging study. J. Neurosurg. 93 (6), 1019 – 1025. Salgado-Pineda, O., Baseza, I., Perez-Gomez, M., Vendrell, P., Junque, C., Bargallo, N., Bernado, M., 2003. Sustained attention impairment correlates to gray matter decreases in first episode neuroleptic–naı¨ve schizophrenic subjects. NeuroImage 19 (2 Pt 1), 365 – 375. Scheepers, F.E., Gispen de Wied, C.C., Hulshoff Pol, H.E., Kahn, R.S., 2001. Effect of clozapine on caudate nucleus volume in relation to symptoms of schizophrenia. Am. J. Psychiatry 158 (4), 644 – 646. Seeman, P., 2002. Atypical antipsychotics: mechanism of action. Can. J. Psychiatry 47 (1), 27 – 38. Sigmundsson, T., Sucking, J., Maier, M., Williams, S.C.R., Bullmore, E.T., Greenwood, K.E., Fukuda, R., Ron, M., Toone, B.,

84

L. McCormick et al. / Schizophrenia Research 80 (2005) 73–84

2001. Structural abnormalities in frontal, temporal, and limbic regions and interconnecting white matter tracts in schizophrenic subjects with prominent negative symptoms. Am. J. Psychiatry 158 (2), 234 – 243. Spurney, C.F., Baca, S.M., Murray, A.M., Jaskiw, G.E., Kleinman, J.E., Hyde, T.M., 1999. Differential effects of haloperidol and clozapine on ionotropic glutamate receptors in rats. Synapse 34 (4), 266 – 276. Stahl, S.M., 2000. Anitpsychotic agents. Essential Psychopharmacology, second ed. Cambridge University Press, Cambridge, UK, pp. 401 – 458. Stahl, S.M., 2001. bHit-and-runQ actions at dopamine receptors, part 1: mechanism of action of atypical antipsychotics. J. Clin. Psychiatry 62 (10), 670 – 671. Suhara, T., Okubo, Y., Yasuno, F., Suod, Y., Inoue, M., Ichimiya, T., Nakashima, Y., Nakayama, K., Tanada, S., Suzuki, K., Halldin, C., Farde, L., 2002. Decreased dopamine D2 receptor binding in the anterior cingulate cortex in schizophrenia. Arch. Gen. Psychiatry 59 (1), 25 – 30. Sun, Z., Wang, F., Cui, L., Breeze, J., Du, X., Wang, X., Cong, Z., Zhang, H., Li, B., Hong, N., Zhang, D., 2003. Abnormal anterior cingulum in subjects with schizophrenia: a diffusion tensor imaging study. Neuroreport 14 (14), 1833 – 1836. Suzuki, M., Nohara, S., Hagino, H., Kurokawa, K., Yotsutsuji, T., Kawasaki, Y., Takahashi, T., Matsui, M., Watanabe, N., Seto, H., Kurachi, M., 2002. Regional changes in brain gray and white matter in subjects with schizophrenia demonstrated with voxel-based analysis of MRI. Schizophr. Res. 55 (1–2), 41 – 54. Szeszko, P.R., Bilder, R.M., Lencz, T., Pollack, S., Alvir, J.M., Ashtari, M., Wu, H., Lieberman, J.A., 1999. Investigation of frontal lobe subregions in first-episode schizophrenia. Psychiatry Res. 90 (1), 1 – 15. Szeszko, P.R., Bilder, R.M., Lencz, T., Ashtari, M., Goldman, R.S., Reiter, G., Wu, H., Lieberman, J.A., 2000. Reduced anterior cingulate gyrus volume correlates with executive dysfunction in men with first episode schizophrenia. Schizophr. Res. 43 (2–3), 97 – 108. Theberge, J., Al-Semaan, Y., Williamson, P.C., Menon, R.S., Neufeld, R.W., Rajakumar, N., Schaefer, B., Densmore, M., Drost, D.J., 2003. Glutamate and glutamine in the anterior cingulate

and thalamus of medicated subjects with chronic schizophrenia and healthy comparison subjects measured with 4.0-T proton MRS. Am. J. Psychiatry 160 (12), 2231 – 2233. Velakoulis, D., Wood, S.J., Smith, D.J., Soulsby, B., Brewer, W., Leeton, L., Desmond, P., Suckling, J., Bullmore, E.T., McGuire, P.K., Pantelis, C., 2002. Increased duration of illness is associated with reduced volume in right medial temporal/anterior cingulate grey matter in subjects with chronic schizophrenia. Schizophr. Res. 57 (1), 43 – 49. Vollenweider, F.X., Leenders, K.L., Scharfetter, C., Maguire, P., Stadelmann, O., Angst, J., 1997. Positron emission tomography and fluorodeoxyglucose studies of metabolic hyperfrontality and psychopathology in the psilocybin model of psychosis. Neuropsychopharmacology 16 (5), 357 – 372. Wang, H., Pickel, V.M., 2002. Dopamine D2 receptors are present in prefrontal cortical afferents and their targets in patches of the rat caudate–putamen nucleus. J. Comp. Neurol. 442 (4), 392 – 404. Williams, S.M., Goldman-Rakic, P.S., 1993. Characterization of the dopaminergic innervation of the primate frontal cortex using a dopamine-specific antibody. Cereb. Cortex 3 (3), 199 – 222. Williams, S.M., Goldman-Rakic, P.S., 1998. Widespread origin of the primate mesofrontal dopamine system. Cereb. Cortex 8 (4), 321 – 345. Woods, S.W., 1992. Regional cerebral blood flow imaging with SEPCT in psychiatric disease: focus on schizophrenia, anxiety disorders, and substance abuse. J. Clin. Psychiatry 53 (Suppl), 20 – 25. Woods, S.W., 2003. Chlorpromazine equivalent doses for the newer atypical antipsychotics. J. Clin. Psychiatry 64 (4), 663 – 667. Yucel, M., Stuart, G.W., Maruff, P., Wood, S.J., Savage, G.R., Smith, D.J., Crowe, S.F., Copolov, D.L., Velakoulis, D., Pantelis, C., 2002. Paracingulate morphologic differences in males with established schizophrenia: a magnetic resonance imaging morphometric study. Biol. Psychiatry 52 (1), 15 – 23. Zink, M., Schmitt, A., May, B., Muller, B., Demirakca, T., Braus, D.F., Henn, F.A., 2004. Differential effects of long-term treatment with clozapine or haloperidol on GABAA receptor binding and GAD67 expression. Schizophr. Res. 66 (2–3), 151 – 157.