The finding: Overall, deep brain stimulation (DBS) of the ventral capsule/ventral striatum does not appear to significantly affect neuropsychological functioning based on comparison of active versus sham (stimulator placed but not activated) DBS. For individual patients, increased age may be associated neuropsychological decline (on at least one measure) regardless of active/sham status; younger patients may be more likely to experience improvement (on at least one measure) with active treatment. Further study of neuropsychological outcome in DBS (based purely on post-surgical status and on active vs sham treatment) is warranted.

Strengths and weaknesses: The strengths of this paper primarily derive from the original study (Dougherty DD, et al: A randomized sham-controlled trial of deep brain stimulation of the ventral capsule/ventral striatum for chronic treatment-resistant depression. Biol Psychiatry 2015; 78(4):240-248). That study, and, by extension, this one, were fairly rigorously executed. The initial study might have been described in a bit more depth here, and the reader might find it inconvenient to go back to the original study in order to best understand this one. However, given the ground-breaking nature of that study, the inconvenience is well worth it. While this paper does not find significant cognitive changes in sham vs active DBS patients, the possible changes at individual levels in young-old, sham-stim patients, would provoke interesting discussions with trainees about the cognitive vulnerabilities of the elderly, the effects of anatomic/surgical vs electrical intervention (“wires vs juices”), and the value of double-blinded studies.

Relevance: As psychiatry increasingly strives toward greater interventional potential, it is increasingly important to understand those interventions that are currently being performed. DBS is perhaps the most important intervention for psychosomatic medicine specialists to understand given the interdisciplinary, particularly neurosurgical, medical participation involved.

Strengths: This study addresses a gap in the literature: the prevalence of positive onconeuronal antibodies in patients presenting with acute psychiatric symptoms is unknown. An N of 585 acutely ill psychiatric patients represents a fairly adequate screening sample on which to base clinical decisions (i.e., whether to screen patients for intracellular/onconeuronal antibodies), particularly when no other suspicious paraneoplastic or other clinical features are present. Affective, psychotic, personality disorders, and other common psychiatric disorders are well-represented. This is particularly relevant for psychotic disorders, as limbic encephalitis often presents with features of psychosis and/or delirium.

Weaknesses: There is no control group. Furthermore, some patients needed admission to medical or neurological units and data from these patients are unclear. This could be particularly relevant as affective, psychotic, or cognitive changes could be due to the presence of a hitherto undiscovered paraneoplastic, autoimmune, or other condition in which positive onconeuronal antibodies could ultimately be discovered. Many patients who were admitted with acute psychiatric illness did not participate (585 out of 832 patients, an inclusion rate of ~70%, participated) and it is unclear if this was because of cognitive (i.e., delirium), psychotic, or other conditions one may see as being correlated with onconeuronal antibodies. Follow-up data is not available so it is unknown if these patients ultimately developed other features consistent with malignancy and/or paraneoplastic syndromes. Finally, many of these patients were described as experiencing exacerbations of previously diagnosed psychiatric disorders. In practice, unless these patients’ clinical presentation differed significantly from prior acute bouts of illness, it would be unlikely that similar symptom patterns would be attributable to undiscovered paraneoplastic processes, particularly if these conditions had been successfully treated via conventional means (this is unclear in the current study).

Relevance: Maintaining an open mind and thinking broadly about possible neuropsychiatric etiologies for acute psychiatric illnesses is good for patient care. The current study does not show that “random screening” for onconeuronal antibodies in patients with acute psychiatric illnesses is beneficial. Clinicians are reminded not to pursue invasive workups “just because.” We are reminded that the complexity of acute psychiatric illnesses cannot be reliably attributed to certain biomarkers without having more specific information from the history and exam.