Psychiatrists are medical doctors who have pursued and expanded their expertise to include education and training in the assessment, specialized treatment, prevention and healing of mental diseases and defects stemming from both physiological and psychological causes. Because they combine both medical and mental health expertness; psychiatrists can evaluate and treat patients in an integrative manner; thereby assuring the patient of the full range of benefits arising from a dualistic approach. To simplify, a psychiatrist is a medical physician who has also become an expert in the field of mental health and emotional well-being.