Chemo brain – A psychotropic drug phenomenon?

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Summary

The phenomenon of ‘chemo brain’ refers to a cluster of potentially long-lasting, cognitive deficiencies which are caused by systemic cancer treatments. While the oncology community has gradually acknowledged the existence of chemo brain as an unintended consequence of anti-neoplastic therapies, other fields of medicine have been less astute. Preliminary research evidence has suggested a role for many existing psychopharmaceuticals in fighting malignancies, based upon the capacity of these drugs to modify gene expression, cell turnover, and cell death (e.g., apoptosis). The author presents the hypothesis that the same mechanisms which suppress the growth and survival of cancer cells may pose similar hazards to non-diseased neurons, thereby inducing the cognitive changes which oncologists have come to associate with chemo brain. The article discusses the specific examples of valproic acid, clomipramine, and fluoxetine as treatments for solid tumors, primary brain tumors, and Burkitt’s lymphoma, respectively. Clinicians, regardless of specialization, are encouraged to consider the potential reality of psychotropic chemo brain, in order to avoid or limit the use of medications which cause it, and in order to prioritize the delivery of rehabilitative strategies in an effort to mitigate or reverse its features.

Section snippets

Introduction: What is chemo brain?

The term ‘chemo brain’ refers to a spectrum of cognitive deficiencies which affect some 4–75% of cancer patients following treatment with chemotherapy [1], [2], [3]. Ranging in intensity from transient and mild, to intractable and severe, the main features of chemo brain include decrements in attention, concentration, memory, language, reaction time, speed of information processing, judgment, and planning [4], [5]. Despite its clinical significance, however, clinicians have been slow to

Evidence that chemotherapies cause chemo brain

Researchers at the University of Colorado performed a longitudinal investigation of eight breast cancer survivors, using a combination of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) techniques [6]. The neuroimaging studies were obtained at baseline (prior to chemotherapy), after the completion of induction chemotherapy (multiple cycles of doxorubicin hydrochloride, fluorouracil, and methotrexate), and again at intervals of 1, 3, 6, 9, and 12 months following the

Psychiatric drugs: evidence of cancer fighting properties

As oncologists have begun to accept the reality of chemo brain, along with the responsibility for modifying or avoiding the therapies which cause it, psychiatrists have been slow to recognize the possibility that their prevailing drug treatments may be similarly cytotoxic. An expanding body of scientific research has documented the potential utility of existing psychopharmaceuticals in the treatment of various cancers, based primarily upon in vitro findings Table 1.

The realization that a number

In vitro evidence for psychotropic chemo brain

Several recent investigations are pertinent to the discussion of psychotropic chemo brain. In a study of neuroleptic therapies, researchers in Israel screened a number of phenothiazines (thioridazine, perphenazine, fluphenazine) for their potential anti-tumor effects upon cancers of the brain [16]. The experimental procedures involved a number of sophisticated assays to determine drug-related changes in cell death and cell proliferation. Lab cultures included a rat glioma cell line, a human

In vivo evidence for psychotropic chemo brain

It is significant that clinical trials in the field of oncology have already capitalized upon the cytotoxic properties of psychiatric drugs. For example, researchers at the Moffitt Cancer Center in Florida recently published the results of the first Phase I drug trial using valproic acid as an adjuvant treatment for advanced solid tumors in humans [24]. Drawing upon the knowledge that valproic acid functions as an inhibitor of histone deacetylases (an effect which ultimately results in

Summary

A growing number of scientists are investigating the potential utility of psychotropic drugs in the treatment of cancer. Ironically, as specialists in the field of oncology have finally acknowledged the capacity of their longstanding chemotherapies to induce an iatrogenic condition known as chemo brain, psychiatrists have ignored a parallel condition of their own. Given the expanded utilization of psychotropic drugs in all specialties of medicine, the time has arrived for physicians to consider

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