Switching to antipsychotic monotherapy can improve attention and processing speed, and social activity in chronic schizophrenia patients.
OBJECTIVE
This study sought to examine whether switching polypharmacy therapy to monotherapy would improve the cognitive function and social function of patients with schizophrenia.


METHODS
Thirty-nine patients with schizophrenia who were receiving therapy with two antipsychotics were randomly divided into a switch to monotherapy group (switching group) and a polypharmacy continued group (continuing group). For the patients allocated to the switching group, the dose level of one of the two antipsychotic drugs was gradually reduced to zero. Psychotic symptoms, cognitive function and social function scale scores were assessed immediately before and 24 weeks after switching, and the time courses of these scores were compared between the two groups.


RESULTS
Compared with the continuing group, the switching group demonstrated significantly greater improvement in attention after switching (p = 0.02). Furthermore, the improvement in daily living (p = 0.038) and work skills (p = 0.04) was significantly greater in the switching group. In an analysis of the correlation among sub-items with respect to the degrees of improvement, a significant correlation was noted between improvement in executive function and improvement in daily living (r = -0.64, p = 0.005) and between improvement in work skills and improvement in attention (r = -0.51, p = 0.038).


CONCLUSIONS
In patients with schizophrenia receiving polypharmacy, switching to monotherapy resulted in improvements in attention. Furthermore, improvements in executive function led to improvements in daily living, and improvements in attention led to improvements in work skills. Thus, switching to monotherapy is a useful option.
Department of Psychiatry, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 8078555, Japan. Electronic address: hori-h@med.uoeh-u.ac.jp.
Hikaru
H
Hori
Reiji
R
Yoshimura
Asuka
A
Katsuki
Atsuko-Ikenouchi
AI
Sugita
Kiyokazu
K
Atake
Jun
J
Nakamura
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000209:etiology; D002908:Chronic Disease; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology; D004334:Drug Administration Schedule; D057915:Drug Substitution; D005260:Female; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000150:complications / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D012919:Social Behavior; D016896:Treatment Outcome; D055815:Young Adult
D014150:Antipsychotic Agents
BACS-J; Brief Assessment of Cognition in Schizophrenia, Japanese-language version; Cognitive function; LASMI; Life Assessment Scale for the Mentally III; Monopharmacy; PANSS; Polypharmacy; Positive and Negative Syndrome Scale; Schizophrenia; Social function; Switching