In Forensic Psychiatry, the expert is often asked to comment on the risk of violence in a patient with mental illness. The classical patterns of relationship between crime and mental illness include the response to psychotic symptoms,“compulsive desires” and personality disorder (impulsivity, intolerance to frustration, antisocial behaviors, …).

Over the decades, there have been changes, and nowadays it is assumed that: there is a relationship between mental illness and violence, the majority of psychiatric patients is not violent, violent behaviors occur usually in acute episodes, the greatest risk of violence in these patients is the occurrence of co-morbidity with alcohol and drugs.

The aim of this retrospective study is to describe the pattern of the relationship between mentall illness and violence, in subjects who may have committed a crime and were submitted to a forensic assessment, in the Central Region of Portugal in 2011. To achieve this aim, we consulted the reports of Forensic Psychiatric expertises, from the Center Delegation (Coimbra) of the National Institute Forensic Medicine.

Following variables were collected: gender, age, marital status, education, occupation, residence, type of crime, kind of victim, previous psychiatric diagnosis, prior psychiatric follow-up, previous psychiatric hospitalization, prior violent acts, existence of psychopharmacological treatment when the crime occured, psychopathology found during the forensic evaluation, existence of comorbid substance use, maladaptive personality traits or diminished IQ. Data analysis was performed with SPSS and Student ‘s t-test.

Our results are in concordance with the available data regarding the weighting factors in assessing the risk of violence.