Psychiatric emergency services (PES) are a main entry for patients with acute mental disorders. Most of them are voluntarily treated and a shared decision making model is implicitly used. Not much is known about decision making capacity (DMC) of patients and the utility of a shared decision making model in PES.

To assess neuropsychological abilities of DMC in a convenience sample of patients admitted to a PES.

Patients were assessed when discharged from the PES. A DSM-IV-TR diagnosis was generated. Neuropsychological abilities were assessed by the Trail Making Test (TMT), Stroop Colour-Word Test (SCWT) and the Mini-Mental State Examination (MMSE). MMSE was used a general assessment of cognitive functioning, TMT and SCWT as a more specific assessment of executive functioning. Patients with marked agitation, no cooperation or withdrawal symptoms were excluded.

47 patients were assessed. Most prevalent primary diagnoses were depressive disorder (11), adjustment disorder (8) and substance abuse/dependence (17). MMSE scores were normal in 87% of patients. SCWT and TMT differential scores were below the 20th percentile in 57% and 61% of patients respectively.

Cognitive functioning in patients, admitted to a PES, seems impaired when assessed by the TMT and SCWT. When replicated in further trials (larger study population, use of more extensive assessment of different components of DMC, careful consideration of ecological validity of these assessments), the implicit idea of a shared decision making model of care should be questioned.