In prisons, the prevalence of mental disorders and death by suicide reach proportions far above that of the general population : the risk of suicide being 11 to 14 times higher. Based on a sample of 565 newly incarcerated individuals, the relationship between suicide attempts and mental disorders was studied, with an emphasis on the attention deficit hyperactivity disorder (ADHD). Results show that a possible presence of ADHD in a prisoner increases the likelihood of having already attempted suicide, as well as the presence of an Axis I and II disorders.