ABSTRACT
In any antidepressant study, placebo response in patients assigned active drug is a troubling source of variance. There have been few attempts to identify the patients whose conditions improve as a result of true drug effect, in contrast with improvement that is a result of nonspecific effects. In a previous report we demonstrated that true drug effect seemed to be characterized by a two-week delay in onset and persistence. We described a method of pattern analysis to identify such patients. In this report, we describe the use of pattern analysis to replicate our initial findings. Data from a new sample of 150 nonmelancholic patients support the hypothesis that true drug effect is characterized by a two-week delay in onset and persistence of improvement, once achieved. There was little evidence of the onset of antidepressant effect before two weeks. The theoretical and clinical implications of this work are discussed.
Subject(s)
Depressive Disorder/drug therapy , Imipramine/therapeutic use , Phenelzine/therapeutic use , Actuarial Analysis , Clinical Trials as Topic , Depressive Disorder/psychology , Humans , Patient Dropouts , Pattern Recognition, Automated , Placebos , Psychiatric Status Rating Scales , Random Allocation , Regression Analysis , Time FactorsABSTRACT
Forty-seven nonmelancholic depressed outpatients were infused with sodium lactate to explore the relationship between history of panic attacks and lactate-induced panic. Lactate panic was rated without knowledge of history of panic. Fifteen of 29 patients (52%) with a history of spontaneous panic experienced panic attacks in response to lactate. Only 1 of 18 patients (6%) without a history of spontaneous panic experienced a lactate-induced panic attack--a highly significant difference. The likelihood of lactate panic was related to frequency of spontaneous panic attacks. The implications of these findings for understanding the relationship of panic attacks and depression are discussed.