Mechanical restraint is a therapeutic procedure commonly applied in acute units in response to psychomotor agitation. Its frequency is between 21 and 59% of patients admitted. These patients represent a risk to both themselves and for health workers. There is a myth that patients with substance use disorder (SUD) are more aggressive and require more forceful measures. There are not clinical studies that compared if there are differences of the frequency of mechanical restrain in patients with SUD.

The aim of this study is to explore the differences of frequency of mechanical restraint on patients with SUD in the psychiatry acute and dual pathology units and others psychiatric diagnostics.

We reviewed retrospectively the informatics record of all the mechanical restraints made and the total discharges of the three acute care units and dual disorders of Neuropsychiatry and Addictions Institute (INAD) of the Parc de Salut Mar de Barcelona, between January 2012 and January 2015. For every discharge the presence of at least one mechanical restraint and the DSM-IV diagnostic were coded. Then was calculated the frequency and proportion of mechanical retrains in every diagnostic group.

The number of discharges analyzed was 4659 from which 838 had an episode of mechanical restraint. The 37% of patients with SUD of cocaine had an episode of mechanical restrain. The patients with SUD of alcohol only the 4%, and there no one case on patients with SUD of Cannabis. Thirty percent of patients with schizophrenia and 28% of bipolar disorder.

L. Galindo is a Rio-Hortega-fellowship-(ISC-III;CM14/00111).

The authors have not supplied their declaration of competing interest.