Whereas the present Swedish case-control analysis did not yield any evidence for association with the diagnosis, the present meta-analysis suggests that the DRD3 gene confer susceptibility to schizophrenia. Reasons for the discrepancies between prior studies are discussed.

Compared to healthy controls, unmedicated schizophrenic patients had significantly higher plasma concentrations of taurine, methionine, valine, isoleucine, leucine, phenylalanine, and lysine. Except for taurine, these amino acids share the L-transport system for neutral amino acids. In the patients, homovanillic (HVA) acid levels in CSF were decreased and the plasma levels of the amino acids competing with tyrosine and tryptophan for transport into the brain, were all negatively correlated to the CSF concentrations of HVA and 5-HIAA. These findings could be explained by a change in the affinity of the L-system or by a decrease in its overall capacity in schizophrenia. Raised plasma levels of the competing amino acids may limit the brain uptake of tyrosine, leading to a diminished dopamine turnover, and resulting in a compensatory development of supersensitive dopamine receptors.

No abstract

Zuclopenthixol acetate--a new injectable formulation with a duration of action of 2-3 days--was compared with conventional intramuscular and oral formulations of haloperidol and zuclopenthixol in the initial treatment of acutely disturbed, psychotic patients. The patients were stratified into 3 diagnostic categories: acute psychoses (48 patients), mania (22 patients), and exacerbation of chronic psychoses (73 patients). The patients were rated on the Brief Psychiatric Rating Scale (BPRS), the Bech-Rafaelsen Mania Rating Scale (BRMAS) (only manic patients) and globally on the Clinical Global Impression (CGI). The study was an open, randomized multicentre trial with a 6-day treatment period. The zuclopenthixol acetate patients received 1-4 doses, the haloperidol patients 1-26 and the zuclopenthixol patients 1-22 doses. The assessments on the CGI showed that all 3 treatments caused a clear reduction of the severity of illness scores in all 3 diagnostic categories, with no differences between treatments. The ratings of the acute and chronic psychotic patients on the BPRS also showed significant reductions in scores with no differences between treatments. All 3 treatments caused a rapid remission of symptoms on the BRMAS. Haloperidol induced hypokinesia in significantly more patients than zuclopenthixol acetate after 24 h. Later there were no significant differences between treatments. Zuclopenthixol acetate fulfils many desires for an amended neuroleptic formulation for the initial treatment of acutely disturbed psychotic patients.

Three dose levels (5, 25, and 50 mg once daily) of the selective serotonin uptake inhibitor citalopram were compared in a four-week, double-blind trial in depressed patients. Serum levels of citalopram and desmethylcitalopram, and the inhibitory effect of serum on serotonin uptake by fresh platelets, were assessed once weekly during the trial. The serum concentrations of citalopram were highly correlated with inhibition of serotonin uptake. Less of the metabolite was found, it being detected only in the higher dose groups. Steady state levels of citalopram, attained after 1 week, were linearly related to dose. The relationship between improvement (percentage reduction in total score on the Montgomery-Asberg Depression Rating Scale) and serum level of citalopram indicated a lower limit of effect in endogenous depression at about 100 nM, corresponding to an average dose of 15 mg. Marked improvement was seen in ten patients with steady state levels in the range 70 to 335 nM. The ten nonendogenously depressed patients had steady state levels from 15 to 620 nM; complete remission was seen in the three with the lowest levels (15-25 nM). No significant correlation was found between serum drug level and the few reported side effects.