In many studies, a significant drug effect can be seen after 1 or 2 weeks. However, if drugs with novel mechanisms are the focus of investigation then assumptions about time course of response might be less reliable. There is also a subgroup of patients

who are slower to respond and if the ultimate goal is to compare the full therapeutic potential of alternative treatments, then a Inhibitors,research,lifescience,medical longer trial might be desirable. Issues related to trial duration in maintenance of effect/relapse prevention LBH589 studies will be discussed subsequently. Outcome and assessment measures The selection of assessment measures and instruments will be largely driven by the choice (s) of the primary and secondary outcome measures as well as by feasibility and rater/patient burden. Often, too many scales are included in a clinical trial and

some of the Inhibitors,research,lifescience,medical data are never analyzed or published. Attention to scale validity and reliability is also important, and in regulatory trials there is a particular emphasis on instruments, which have been demonstrated on a broad scale to have the desired characteristics. If a new scale is introduced, it Inhibitors,research,lifescience,medical is often recommended to have an existing and widely utilized scale for the same domain included as a reference point. As there is increasing emphasis on patient reported outcomes, however, there is also some concern as to the validity of such measures for those individuals who are lacking in insight or unable to reliably evaluate their own Inhibitors,research,lifescience,medical subjective and/or functional state. In the case of schizophrenia, informant information can also be extremely

valuable. Patient-reported outcomes in some cases can be im0peded by willful concealment or distrust of the interviewer or interview situation. Clearly, as broader outcome assessments are called for, measures of negative symptoms, cognitive function, social and vocational performance/quality Inhibitors,research,lifescience,medical of life, subjective well-being, family burden, etc should be considered. In contrast to some dimensions of psychopathology, the longer time frame needed to assess the amelioration of negative symptoms and cognitive dysfunction or improvements in overall social and vocational adjustment might require trials of much longer duration. This is especially true if issues of persistence of effect are to be clarified. Finally, it has been recognized that adverse of effects are not as carefully and comprehensively measured as efficacy- measures.79 This should also be remediated by adding a brief interview based or self-administered adverse effect check list to spontaneous reporting. Quality of ratings and fidelity of assessments In order to have a sufficient signal-to-noise detection ratio for diagnostic, symptomatic and side effect assessments, both the utilized tools and the raters performing the interviews and ratings need to be highly reliable.