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Monday, 25.09.2017

Reply to Elemer Szabadi’s comment by Donald F. Klein

MARTIN KATZ: ONSET OF ANTIDEPRESSANT EFFECT

Reply by Donald Klein on Comment by Elemer Szabadi

The debate between Martin Katz and myself centers on the question of how soon after antidepressant treatment is initiated does specific treatment benefit become manifest. The relevant measures used were weekly psychiatric scales, in placebo controlled clinical trials.

Dr. Szabadi (Szabadi et al., 1976) proposes an alternative measure: decreases in the speech pause time during automatic counting. His pilot study of four subjects during antidepressant treatment was promising. The article does not refer to the “small group” that showed effects during the first treatment week. Since there were only 4 subjects, one wonders at the size of this subgroup.

However, several studies found similar findings relating decreased speech pause time to improvement in depression. One mentioned that agitated depressions showed opposite effects. I was unable to find any placebo controlled clinical trial that used speech pause time as a dependent measure and I would appreciate such references.

Dr. Szabadi's simple, objective observation has been neglected. Any contribution to the Katz-Klein disagreement depends on its relative value to the usual scales for detecting clinical improvement. Conceivably, it might be measuring the degree of retardation, which is clinically difficult to evaluate but is an important component of remission.

If it were shown that only those drug treated patients with marked decreases in pause time during the first treatment week went on to substantial clinical improvement, this would be in harmony with Marty's views. Contrariwise, if many patients showed a later onset of substantial maintained improvement that would argue against the stand that early improvement can serve as a surrogate for eventual improvement.

I think the data generated by scales have already invalidated Katz's hypotheses. Nevertheless, such promising alternative measures are, in principle, welcome. Funding their evaluation is another issue.

 

Donald F. Klein

October 22, 2015