in most cases what appear to be the two main causes of emotional or behavioral disorders
Causes of mental disorders During most of the 20th century, mental illness was believed to be caused by problematic relationships between children and their parents. This view was held well into the late 1990s, in which people still believed this child-parent relationship was a large determinant of severe mental illness, such as depression and schizophrenia. Today,[when?] the belief is held that the child-parent relationship is of small importance in terms of causing mental illness compared to biological and genetic factors[citation needed]. So, the perceived causes of mental illness have changed over time and will most likely continue to alter while more research is done in this area.[15]
Psychosexual development In Freudian psychology, psychosexual development is a central element of the psychoanalytic sexual drive theory, that human beings, from birth, possess an instinctual libido (sexual energy) that develops in five stages. Each stage – the oral, the anal, the phallic, the latent, and the genital – is characterized by the erogenous zone that is the source of the libidinal drive. Sigmund Freud proposed that if the child experienced sexual frustration in relation to any psychosexual developmental stage, he or she would experience anxiety that would persist into adulthood as a neurosis, a functional mental disorder.[1][2]