The presence of mixed features in bipolar disorder (BD) has been associated with a worse clinical course and high rates of comorbidities including anxiety, personality, alcohol and substance use disorders and head trauma or other neurological problems [1]. A recent study reports the connection of neurosyphilis and mania [2]. The aim of our study is to evaluate an inpatient with a psychotic mixed state due to a medical condition (neurosyphilis).

An inpatient with psychotic mixed state in BD was assessed with: SCID-P, HRSD, YMRS, and a complete internistical examination, blood test exams, urinanalysis, electrocardiogram and ecocardiogram, as well as a first level brain imagin (CT and/or MRI). We conducted a systematic review of the literature (PubMed, Embase, PsychInfo), using the terms “bipolar disorder”, “neurosyphilis” AND “mixed state”.

A comprehensive diagnostic and laboratory screening was unremarkable except for a positive venereal disease research laboratory (VDRL). Treatment for syphilis was started and we used olanzapine to control the psychiatric symptoms.

The estimated annual incidence of non-HIV STIs (sexually transmitted infections) has increased by nearly 50% during the period 1995–2008 [3]. Our case report underly, like Barbosa et al., the need to evaluate neurosyphilis as a potential cause of behavioural and psychiatric symptoms that simulate a psychotic mixed state of bipolar disorder. Olanzapine control and improve the psychiatric symptomatology in neurosyphilis. Methodological limitations, clinical implications and suggestions for future research directions are considered.

The authors have not supplied their declaration of competing interest.