When a person can no longer cope with everyday life, they may be said to not be functioning adaquatley
Rosenhan & Seligman proposed some signs to tell us if someone is failing to function aqauatley:
No longer conforms to interpersonal rules - standing too close to people, eye-contact
when they experience personal distress
when they become irrational or dangerous to others
Having an intellectual disability disorder many not allow an individual to function adequately
Rosenhan and Seligman's features of failure to function:
maladaptive behaviour (behave in ways that go against their long term intrests
Personal anguish (distress and anxiety)
Observer discomfort
Irrationality
Unconventionality (behaviour dosent match what is typically expected in society)
A criticism of this definition is that the decision of whether someone is coping or not is subjective. This means that two observers may disagree on whether someone is coping.
A criticism is that not all maladaptive behaviour indicate mental illness, For example, smoking, drinking and eating unhealthy food all risk health, so they are arguably maladaptive. However, this does not mean that the individual has a mental health problem
A positive aspect is that it respects individuals and their own experience and views