The aim of this critical review was to outline emerging trends and perspectives of clinical pharmacopsychology, an area of clinical psychology that is concerned with the psychological effects of medications. The historical development of clinical pharmacopsychology is outlined, with discussion of its most representative expressions and reference to current challenges of clinical research, with particular reference to clinimetrics. The domains of clinical pharmacopsychology encompass the clinical benefits of psychotropic drugs, the characteristics that predict responsiveness to treatment, the vulnerabilities induced by treatment (side effects, behavioral toxicity, iatrogenic comorbidity), and the interactions between drug treatment and psychological variables. Its aim is to provide a comprehensive assessment of the clinical important changes that are concerned with (a) wanted and expected treatment effects, (b) treatment-induced unwanted side effects, and (c) the patient's own personal experience of a change in terms of well-being and/or quality of life. Clinical pharmacopsychology offers a unifying framework for the understanding of clinical phenomena in medical and psychiatric settings. Research in this area deserves high priority.