The impact of neuroleptic dosage and extrapyramidal side effects on schizophrenic basic symptoms

The impact of neuroleptic medication and extrapyramidal symptoms on abnormal subjective experiences in schizophrenia, also termed basic symptoms, as assessed with the Frankfurt Complaint Questionnaire (FCQ) was investigated in 40 schizophrenic patients medicated with conventional neuroleptics. Basic symptoms are thought to reflect the subjective side of schizophrenic vulnerability and to underlie schizophrenic symptomatology. It was expected that basic symptoms would inversely correlate with chlorpromazine equivalents, since neuroleptics not only improve acute schizophrenic symptoms but also have prophylactic properties. However, a significant positive correlation with neuroleptic dosage and extrapyramidal symptoms emerged, suggesting that basic symptoms as operationalized in the FCQ partly reflect neuroleptic-induced deficits. The results remained unchanged when global psychopathology was controlled for. In line with previous research, basic symptoms correlated with thought disorder but not with positive symptoms. However, when the effects of neuroleptic-induced disturbances were controlled for, thought disorder also insignificantly correlated with basic symptoms. Our findings confirm previous results that question the construct validity of the FCQ. Moreover, the need to control for confounding variables (such as medication) is emphasized by comparing different psychiatric groups.