This lengthy and ambitious book is predominantly concerned with the explanation and treatment of the DSM personality disorders of Axis II and much less so with the clinical syndromes of Axis I. Although Millon states that his personality-guided synergistic psychotherapy is conducive to shorter and more effective treatment of the Axis I syndromes, he offers no evidence in this text to support the efficacy of his orientation for either group of disorders. Furthermore, confidence in the many detailed case studies used to illustrate his approach is not enhanced by his admission that many of them preceded the development of his model.

His perspective is purportedly based on his evolutionary model of personality, which presumes that personality and its disorders can be classified and explained in terms of the three polarities of pain-pleasure, active-passive and self-other. Normal individuals show a reasonable balance between each of the polarity pairs. Those with personality disorders are thought to reflect a deficiency in one or more of the three (e.g. the schizoid personality prototype is deficient in both pain and pleasure), an imbalance (e.g. the schizoid personality prototype is strong on passivity and weak on activity), a conflict (e.g. the negativistic personality prototype has a conflict between self and other) and/or a structural defect (e.g. the paranoid personality prototype rigidly compartmentalises each of the three polarity pairs). Fifteen disordered personality prototypes have been identified. In addition, there are various disordered personality subtypes, such as the affectless type of schizoid personality. These subtypes are said to be based on empirical and clinical observation although, as with the personality prototypes, no supporting evidence is presented.

The personality disorders are also described in terms of eight clinical or diagnostic domains, which are shown at one of four levels: expressive behaviour and interpersonal conduct at the behavioural level; cognitive style, self-image and object representations at the phenomenological level; regulatory mechanism and morphological organisation at the intrapsychic level; and mood/temperament at the bio-physical level. The salience of these domains for each personality disorder is displayed graphically by ellipses. The relationship between the polarity pairs and these domains is not explained.

Treatment is outlined at two levels: first, in terms of the more general strategic goals of balancing polarities and countering the way in which disorders are perpetuated; and second, at greater length, in terms of the more specific tactics of therapeutic modalities or techniques directed at particular domains, such as the use of social skills training for developing more appropriate interpersonal behaviour in those with schizoid personality disorder. Millon suggests that treatment is more effective when two different therapeutic modalities are administered at the same time in potentiated pairings, when different therapeutic modalities are given singly in catalytic sequences and when potentiated pairings of the therapeutic modalities are presented in potentiated sequences. The relevant criteria for combining treatments in these supposedly synergistic ways and for choosing between them is not made explicit, making it difficult to apply and to evaluate empirically the approach advocated in this book.