In the past it was believed that mental illness was caused by supernatural forces and evil spirits. Thanks to modern medicine that is a thing of the past. Definition of mental illness is complex and composed of more guidelines which can not be described on its own as only reason for deviations from normal behavior. Psychiatry department provides diagnosis, treatment and health care, which together with staff training rises to a higher level to follow the needs of the patient. During the admission process, treatment and release off the patient with mental illnes there are some ground rules that are protected with principles that are starting point for all nursing interventions. Treatments in psychiatry are divided into psychological, biological and social types. Psychotherapy, using words, changes a patient's reaction to himself and his environment which results in change of personality. It is divided into cognitive, behavioural and psychoanalysis. Biological treatment uses psychotropic, electrostimulative therapy, transcranial magnet stimulation, vagal stimulation and cronobiological methods such as light therapy. It also uses chromotherapy, sleep deprivation, treatment of sleep or dreams, psychosurgery and acupuncture. Social methods include sociotherapy including group therapy, therapeutic community, ocupational and work therapy, recreation and music therapy. Treatment is a collaborative process relying on good plan work so that the patient goes through the therapy smoothly and collaborates during and after hospitalization. The role of the bachelor quote through interventions of health care. Communication is the key professional competence which bachelor of nursing uses in his field of care. Listening is the foundation of the relationship of trust which is essential. Recless communication can cause opposite effect from desired, and that makes all future nurse interventions difficult to do.