Dual Diagnosis

1. Dual Diagnosis • Refers to co-occurring substance use disorder and psychiatric disorder • A number of epidemiological studies (e.g., Grant et al., 2004a; b; c) have shown that those with SUD are more likely to experience a wide range of psychiatric disorders • Lifetime prevalence of SUD among different groups: • No mental illness: 10-15% • Less severe MI: 20-25% • More severe MI: 30-50% • For those with psychiatric disorders, appx. 30% will have a co-occuring SUD

2. Those with co-occurring SUD and psychiatric disorders tend to have worse treatment outcomes (for both problems) • Especially so for Antisocial Personality Disorder (fairly unique case) • Those with co-occurrence are also more likely to use costly services (e.g., ER) • Among adolescents, there is a further complication of internalizing vs. externalizing disorders

3. Why do SUD and psychiatric disorders co-occur? • A number of different models exist • Secondary Psychopathology • Substance use “causes” the mental illness • Difficult diagnostic issue • Theoretically, specific substances should result in specific mental illnesses • Not well-supported • Secondary Substance Abuse • The mental illness “causes” the SUD • Self-medication hypothesis

4. Theoretically, specific substances should lead to specific disorders • Again, not well supported • In many cases patients select drugs that exacerbate their symptoms (e.g., alcohol and depression) • General Dysphoria Theory • Less specific than the self-medication hypothesis (probably what general public thinks of) • Mental illness may impact judgment and appreciation of consequences • Mental illness may increase dependence via enhanced dysphoria • Mental illness may reinforce social context of drug use

5. Supersensitivity Model • Specific psychiatric disorders may make individuals more sensitive to the effects of substances • Some evidence regarding schizophrenia • Secondary Psychosocial Effects Model • Psychosocial effects of mental illness (e.g., problems with work, housing, poor cognitive functioning etc.) predisposes people toward substance abuse • Could probably go the other way as well

6. Common Factor Models • Similar underlying variable increases risk for both SUD and other mental illness • Not well tested • Bidirectional Models • Each illness contributes to and exacerbates the other • Could impact course, symptoms, rapidity of onset, etc. • Needs to be tested longitudinally • PTSD an exception • Psychiatric disorders as a direct, physiological substance-related effect • Specific DSM diagnosis

7. Diagnosing co-occurrence SUD and other disorders • Very difficult process • Often overlooked in each setting • Ideally, observe the person for some time (e.g., 4 weeks) without substance use • Problem with this?

8. Treating co-occurring SUD and other disorders • Comprehensive assessment is key • Among adolescents it needs to be multidimensional • Kids best source for substance use; others for mental illness • Integrated model • Considered a “gold standard” • Patient receives treatment for both disorders from the same team • What are the advantages of this? • What are some of the challenges with this approach? • Seems to provide the best outcomes

9. Other treatment models • Sequential • Treat the most acute condition first • Problems? • Parallel • Both problems are treated simultaneously by different teams • Problems? • Quadrant Model • Useful for understanding individual co-morbidity • Not all co-morbidity is the same • Basically, it involves high-high, high-low, low-high, and low-low