I need some assistance with these assignment. treating a dual diagnosis client Thank you in advance for the help! Dual-diagnosis is used in psychology to refer to the state of a patient which is characterized by the coexistence of a psychological disorder and a substance abuse and addiction problem (Phillips, Olive and Tom 32). Patients with a dual-diagnosis are faced with a significant challenge or problem in dealing with both the psychological illness and a drug problem. It is in this sense that effective assessment approach, diagnosis and treatment which employs an appropriate model is required for dual-diagnosis patients. This paper is based on a case study of David who at 21 years of age is presenting with abnormal behavior which indicates a dual-diagnosis of a psychological disorder and a drug abuse and addiction problem. David is referred for psychological assessment, diagnosis and treatment by his advisor who is concerned about his change of behavior. This paper therefore gives a presentation of effective psychological assessment for David including the ethical considerations during the process of assessing the patient. The paper also describes the process and justification of the diagnosis for David’s co-morbid condition with an illustration of the etiology and the appropriate explanatory model for the diagnosis. Finally, the paper presents an appropriate treatment plan and approach for David which is based on the conclusive diagnosis that is reached during the psychological health care process. Psychological Assessment The psychological assessment for David will be achieved through a comprehensive medical history. This history is gathered by the psychologist in line with the ethics and standards of mental health care. The history involves an attempt to understand David both in the context of the psychological disorder and the drug addiction problem. Therefore David will be assessed through a psychological interviewing process where the psychologist will inquire about the drugs that he would be taking. The assessment for drug abuse will be achieved through a guarantee that David is given about the confidentiality of the information that he would provide as provided by the ethics of health care practice. In addition, David will be assured that the information that he would provide will only be used for making his life better by solving the problems that he would be facing at school or home. In the assessment process, the family history for drug use would be obtained from David. More importantly, the first time of drug use and the duration of substance abuse will be inquired by the psychologist to aid in the diagnosis of his drug problem. In the assessment of David’s psychological disorder, the psychologist will seek to determine when the symptoms of the disorder began to show. This will be achieved through inquiry about David’s childhood life. This should be described by David himself during the interviewing process and used by the psychologist to achieve an accurate assessment of his psychological disorder. By determining the time of onset of psychological symptoms, psychologists are able to determine the duration of a psychological disorder so that an accurate assessment is achieved on the impact of the illness on the social and personal life of the client (Antoni 1005).