failure to function adequately

• A strength of this definition is that it takes into account the patient's perspective and so the final diagnosis will be comprised of the patient's subjective symptoms and not the psychiatrist's objective opinion.

  This may lead to more accurate diagnoses of mental health disorders as these are not constrained by statistical limits like the statistical infrequency definition.
• Psychopaths can cause great harm and still appear normal.

  Harold Shipman, who murdered over 215 of his patients, seemed to maintain a job, personal hygiene, an interpersonal relationship and didn't display features of functioning inadequately and so would be classed as normal according to this definition.

  The focus on how someone is coping may mean that some abnormal behaviour is missed. People may appear fine to others as they fit into society but they may have distorted thinking which causes hidden inner distress and harm to those around them.
• The definition suffers from cultural relativism.

  Using the definition, some people would be classified as abnormal simply because their cultural norms differ from another's.

  What is seen as normal varies within and across cultures and so the definition is ambiguous as the criteria is likely to result in different diagnoses when applied to people from different cultures.