Suicide is far more common than most people believe. The largest number of suicides is in males in younger adulthood, and suicide is the second most common cause of death in the very young. Although there are cases of impulsive suicide with few or no warning signs, the majority of successful suicides occur in individuals who present with more than one characteristic and/or symptom that would indicate an increased risk. High-risk patients for priority intervention, such as dual diagnoses patients and young males, need to be identified and targeted. While suicide is a complex phenomenon in terms of the causes and processes that lead up to it, the extremely strong link to psychiatric disorders is undeniable. These disorders especially include depression, bipolar disorder, schizophrenia, and alcohol and drug abuse/dependence, and severe personality disorders. Psychiatric outpatients are at lower risk than inpatients but are at higher risk than those in the general population who do not have an affective diagnosi. Patients with high risk during the hospitalization and after should be closely followed for suicide attempts. Early diagnosis and effective treatment are of paramount importance to in prevention of the suicide risk associated with these disorders.