Attachment issues or otherwise referred to as attachment disorders has now been supported by scientific research, and the research has supported the theory to such a point that is now the most proven theory psychologists have to work with.
As medical imaging and equipment have evolved scientists and neuropsychologists have been able to convert this theory into fact, enabling psychologists to have real evidence of the disorder via MRI and Cat-Scans.
Attachment issues generally are formed in early infancy from 0 months through to 3 years old. The age in which the disorder is formed is somewhat arguable with some believing 0-18 months.
When a child is not attended to or given what they emotionally or physically need, the structure of brain can change and become irregular, in return making certain normal everyday functions like feeling, self soothing, self regulating emotions and having caring relationships extremely hard for the patient suffering from this disorder. Attachment disorders are usually the precursors to more severe mental illnesses in adult life, that is one of the main reasons it gets treated as soon as it is identified.