This is an approach to the diagnosis and treatment of the major forms of mental disorders found in adults including mood, anxiety and personality disorders, disorders of behaviour and impulses control and others. It integrates the relevant current literature on treatment of major disorders into a structured format that will help clinicians to more quickly assess the client and develop treatment plans with a high probability of success. It will also enable therapists to assess their own level of effectiveness, increase their accountability, deal more effectively with requests of insurance companies and peer review boards and improve the overall quality of their work.