Dual Diagnosis
Establishing an accurate diagnosis for patients in addiction and mental health settings is an important and multifaceted aspect of the treatment process. Clinicians must discriminate between acute primary psychiatric disorders and psychiatric symptoms caused by Alcohol and Other Drugs (AODs). To do so, clinicians must obtain a thorough history of AOD use and psychiatric symptoms and disorders.
There are several possible relationships between AOD use and psychiatric symptoms and disorders. AODs may induce, worsen, or diminish psychiatric symptoms, complicating the diagnostic process.
The primary relationships between AOD use and psychiatric symptoms or disorders are described in the following classification model (Landry et al., 1991a; Lehman et al., 1989; Meyer, 1986). All of these possible relationships must be considered during the screening and assessment process.
AOD use can cause psychiatric symptoms and mimic psychiatric disorders. Acute and chronic AOD use can cause symptoms associated with almost any psychiatric disorder. The type, duration, and severity of these symptoms are usually related to the type, dose, and chronicity of the AOD use.
Acute and chronic AOD use can prompt the development, provoke the reemergence, or worsen the severity of psychiatric disorders.
AOD use can mask psychiatric symptoms and disorders. Individuals may use AODs to purposely dampen unwanted psychiatric symptoms and to ameliorate the unwanted side effects of medications. AOD use may inadvertently hide or change the character of psychiatric symptoms and disorders.
AOD withdrawal can cause psychiatric symptoms and mimic psychiatric syndromes. Cessation of AOD use following the development of tolerance and physical dependence causes an abstinence phenomenon with clusters of psychiatric symptoms that can also resemble psychiatric disorders.
Psychiatric and AOD disorders can coexist. One disorder may prompt the emergence of the other, or the two disorders may exist independently. Determining whether the disorders are related may be difficult, and may not be of great significance, when a patient has long-standing, combined disorders. Consider a 32-year-old patient with bipolar disorder whose first symptoms of alcohol abuse and mania started at age 18, who continues to experience alcoholism in addition to manic and depressive episodes. At this point, the patient has two well-developed independent disorders that both require treatment.
Psychiatric behaviors can mimic behaviors associated with AOD problems. Dysfunctional and maladaptive behaviors that are consistent with AOD abuse and addiction may have other causes, such as psychiatric, emotional, or social problems. Multidisciplinary assessment tools, drug testing, and information from family members are critical to confirm AOD disorders.
The symptoms of a coexisting psychiatric disorder may be misinterpreted as poor or incomplete "recovery" from AOD addiction. Psychiatric disorders may interfere with patients' ability and motivation to participate in addiction treatment, as well as their compliance with treatment guidelines.
For example, patients with anxiety and phobias may fear and resist attending Alcoholics Anonymous or group meetings. Depressed people may be too unmotivated and lethargic to participate in treatment. Patients with psychotic or manic symptoms may exhibit bizarre behavior and poor interpersonal relations during treatment, especially during group-oriented activities. Such behaviors may be misinterpreted as signs of treatment resistance or symptoms of addiction relapse.
AOD Use and Psychiatric Symptoms
AOD use can cause psychiatric symptoms and mimic psychiatric syndromes.
AOD use can initiate or exacerbate a psychiatric disorder.
AOD use can mask psychiatric symptoms and syndromes.
AOD withdrawal can cause psychiatric symptoms and mimic psychiatric syndromes.
Psychiatric and AOD use disorders can independently coexist.
Psychiatric behaviors can mimic AOD use problems.
The Terminology of Dual Disorders
The term dual diagnosis is a common, broad term that indicates the simultaneous presence of two independent medical disorders. Recently, within the fields of mental health, psychiatry, and addiction medicine, the term has been popularly used to describe the coexistence of a mental health disorder and AOD problems. The equivalent phrase dual disorders also denotes the coexistence of two independent (but invariably interactive) disorders, and is the preferred term used in this Treatment Improvement Protocol (TIP).
The acronym MICA, which represents the phrase mentally ill chemical abusers, is occasionally used to designate people who have an AOD disorder and a markedly severe and persistent mental disorder such as schizophrenia or bipolar disorder. A preferred definition is mentally ill chemically affected people, since the word affected better describes their condition and is not pejorative. Other acronyms are also used: MISA (mentally ill substance abusers), CAMI (chemical abuse and mental illness), and SAMI (substance abuse and mental illness).
Common examples of dual disorders include the combinations of major depression with cocaine addiction, alcohol addiction with panic disorder, alcoholism and polydrug addiction with schizophrenia, and borderline personality disorder with episodic polydrug abuse. Although the focus of this volume is on dual disorders, some patients have more than two disorders, such as cocaine addiction, personality disorder, and AIDS. The principles that apply to dual disorders generally apply also to multiple disorders.
The combinations of AOD problems and psychiatric disorders vary along important dimensions, such as severity, chronicity, disability, and degree of impairment in functioning. For example, the two disorders may each be severe or mild, or one may be more severe than the other. Indeed, the severity of both disorders may change over time. Levels of disability and impairment in functioning may also vary.
Thus, there is no single combination of dual disorders; in fact, there is great variability among them. However, patients with similar combinations of dual disorders are often encountered in certain treatment settings. For instance, some methadone treatment programs treat a high percentage of opiate-addicted patients with personality disorders. Patients with schizophrenia and alcohol addiction are frequently encountered in psychiatric units, mental health centers, and programs that provide treatment to homeless patients.
Patients with mental disorders have an increased risk for AOD disorders, and patients with AOD disorders have an increased risk for mental disorders. For example, about one-third of patients who have a psychiatric disorder also experience AOD abuse at some point (Regier et al., 1990), which is about twice the rate among people without psychiatric disorders. Also, more than half of the people who use or abuse AODs have experienced psychiatric symptoms significant enough to fulfill diagnostic criteria for a psychiatric disorder (Regier et al., 1990; Ross et al., 1988), although many of these symptoms may be AOD related and might not represent an independent condition.
Compared with patients who have a mental health disorder or an AOD use problem alone, patients with dual disorders often experience more severe and chronic medical, social, and emotional problems. Because they have two disorders, they are vulnerable to both AOD relapse and a worsening of the psychiatric disorder. Further, addiction relapse often leads to psychiatric decompensation, and worsening of psychiatric problems often leads to addiction relapse. Thus, relapse prevention must be specially designed for patients with dual disorders. Compared with patients who have a single disorder, patients with dual disorders often require longer treatment, have more crises, and progress more gradually in treatment.
Psychiatric disorders most prevalent among dually diagnosed patients include mood disorders, anxiety disorders, personality disorders, and psychotic disorders.