An important person-centred approach to understanding psychopathology hinges on the second of the necessary and suf®cient conditions ± that is that incongruence is central to mental/emotional distress. In his exploration of the links between incongruence and mental health, Tengland (2001: 169) sees incongruence as contributing to ill health `since it often reduces the person's ability to reach vital goals'. This is because when we experience something that con¯icts with how we see ourselves and we cannot make the outer reality ®t with our self image we tend to feel tense, anxious, confused or frightened. To phrase it more formally, when a person has a poor self-concept which is out of touch with the organism, disturbance results and in extreme cases this manifests as distress or even `madness'. This can be framed in terms of conditions of worth (Point 12) which is the classic client-centred view. However, within the broader person-centred family, some theorists have argued that incongruence can arise from causes other than conditions of worth (for example, genetic or other biological causes, life events such as abuse early in life or post-traumatic stress disorder) and there have been attempts to develop models of distress based on understanding incongruence per se.