Eighteen subjects with a DSM IV TR diagnosis of Bipolar 1 Disorder were recruited: ten (11.1 ± 1.0 years; 5 female) were not medicated with any antipsychotic and eight (10.9 ± 1.1 years; 1 female) were medicated with the atypical antipsychotic risperidone (see ). The subjects with BPD, not treated with risperidone, were currently displaying manic or mixed symptoms (with or without psychotic features). All of these subjects had YMRS scores greater than 15. Of the BPD subjects treated with risperidone all had commenced risperidone treatment when presenting with manic or mixed symptoms (with or without psychotic features), and a YMRS score greater than 15. The mean dose of risperidone was 2.09 ± 1.25 mg/day and the mean duration of treatment was 101.14 ± 138.59 weeks (see ). Three of the subjects treated with risperidone were responders and five were in remission.
Table 1 Sex, age, CGI-Mania and YMRS for subjects treated without (No) and with (Yes) risperidone. Risperidone dose (mg/day), duration of risperidone treatment and risperidone response are included for the subjects treated with risperidone. Response: a 30 % decrease (more ...)
Table 2(a) Mean ± standard deviation for the metabolite ratios, YMRS, and CGI-Mania in a group of subjects treated, without (no) and with (yes) risperidone. Also included is the mean ± standard deviation dose and duration of risperidone treatment, (more ...)
Three of the subjects were scanned before and 8 weeks after treatment with risperidone. All of the subjects had a co-morbid diagnosis of ADHD. Additional co-morbid diagnoses include (not treated with risperidone, treated with risperidone): Alcohol Abuse (n = 2, n = 0), Substance Abuse (n = 3, n = 0), OCD (n = 2, n = 0), generalized anxiety disorder (n = 3, n = 3), post traumatic stress disorder (n = 1, n = 2), Oppositional Defiant Disorder (n = 9. n = 5), Conduct Disorder (n = 5, n = 2), Autism (n = 0, n = 1) and Pervasive Developmental Disorder (n = 1, n = 0).
Eight youths were medicated at the time of the study with medications other than risperidone. Five subjects who were not receiving risperidone treatment were medicated with: clonidine (n = 2), a selective serotonin reuptake inhibitor (n = 1), atomoxetine (n = 1) and a stimulant (n = 1). Three subjects who were receiving medication with risperidone were additionally treated with a selective serotonin reuptake inhibitor (n = 1), bupropion (n=1), atomoxetine (n = 1) and a stimulant (n = 1).
All the spectra in this study were fit using LCModel. LCModel gives a time domain fit and a standard deviation (SD%) based on the Cramer-Rao lower bound. The SD% is a measure of the reliability of the fit. A standard deviation of 100 % means the metabolite would need to double in order for a change to be seen. All included spectra in this study had SD % less than 12 % for NAA, Cr, Cho and a SD % less than 16 % for Ins and Glx.
shows the means and standard deviations for all of the measured metabolite ratios (NAA/Cr, Cho/Cr, Ins/Cr and Glx/Cr) and the YMRS and CGI-Mania scales for those subjects treated without and with risperidone.
Multivariate linear regression analysis with Glx/Cr as the dependant variable and age, sex and risperidone status as independent variables showed that risperidone had a significant positive effect on Glx/Cr (df = (3, 17), B = 0.33, t = 2.19, p < 0.05). Significant results were not seen for any of the other metabolite ratios.
Both the YMRS and CGI-Mania scores were significantly different (MANOVA) between the children not receiving risperidone treatment and those receiving risperidone treatment: df = (1, 17), F = 85.22, p < 0.000 and df= (1, 15), F = 42.89, p < 0.000, respectively. The YMRS score and CGI-Mania scores correlated negatively with Glx/Cr (r = −0.59. p < 0.01, and r = −0.55, p < 0.03; respectively).
Tissue segmentation data was acquired from 14 subjects (9 not treated with risperidone, and 5 treated with risperidone). One of the subjects not treated with risperidone and three of the subjects treated with risperidone did not have the SPGR volume scan data necessary to segment the data. There were no significant differences between grey matter, white matter and CSF contributions to the spectroscopic voxels for the two groups ().