The importance of conducting a comprehensive assessment of the potential substance use or mental health problem identified in the screening process has been underscored in recent years by several experts in the field of concurrent disorders.40,41,52,170,178,200 All agree on the critical need for a comprehensive assessment for consumers of mental health services thought to have a substance use disorder, and vise versa for those attending substance abuse services. Assessment is seen as intimately linked to treatment planning and the delivery of quality services.52,178 Assessment data also serve another important function as baseline information for the determination of outcome.41 However, the additional and often complex task at hand, is to investigate the inter-relationship of the mental health disorder(s) and the substance use disorder(s) in terms of their interaction and etiology. As discussed in an earlier section there are many ways in which alcohol and other drug use (AOD) can interact with severe mental health problems.24,41,156,178 Mueser et al.45 provide the most inclusive discussion to date of etiological theories.
There is cause for concern about the reliability of information from substance abuse or mental health assessments conducted with people with concurrent disorders (see Del Boca & Noll,201 for a recent review). There is evidence of lower reliability of self-reported past or current psychiatric disorders among drug abusing versus non-drug-abusing individuals.202,203 There is also lower reliability of self-reported alcohol and drug use and consequences among people with severe mental illness, this being exacerbated by fluctuations in acutse symptomatology, cognitive impairment and mental status.178 Suggestions from Carey & colleagues178,213,218 for improving the accuracy and reliability of self-reported substance use and related problems by people with concurrent disorders include:
One of the strongest recommendations made by experts in the field is for assessment to be conducted over more than one interview and to include multiple sources of information. Assessment should be seen as an ongoing process, that extends over a period of time, including a period of abstinence or significant reduction in use.41 This integrative, longitudinal approach is described, for example, by Drake et al.156 and Kranzler et al.204 Kranzler et al.204 have formalized this integrative approach into the Longitudinal Expert All Data Procedure (LEAD). This integrates all information and observations about the consumer that is available from multiple clinicians and support workers, and over repeated assessments. Carey and Correia41 note that this approach was found to be less effective for concurrent mood and anxiety disorders compared to other comorbidities. The longitudinal approach, however, is critical to sorting out the
"chicken and egg" problem. As noted by Carey and Correia,41 if psychiatric symptoms continue during periods of abstinence this helps establish the DSM-IV criterion of
"not due to substance use". Alternatively, the resolution of some or all of the psychiatric symptoms during periods of little or no use is consistent with a substance-induced disorder.
A primary goal of a comprehensive assessment of substance use or severe mental illness is to confirm diagnoses.41 For substance use disorders this involves making the important distinction between substance abuse or dependence using the criteria of the DSM-IV. This can be done with the substance abuse module of a full diagnostic interview such as the Structured Clinical Interview for Axis I DSM-IV Disorders (SCID-IV).205 For mental health evaluation, a full structured or semi-structured mental health interview is required by a professionally qualified mental health professional.20
The Alcohol Use Scale (AUS) and the Drug Use Scale (DUS)206 are two five point clinician-rating scales that have been developed to classify people with severe mental illness into categories that correspond to the level of severity of substance use. The results also map onto DSM-IV criteria. The clinician makes the ratings using all available information that has been accumulated over a six-month period. Results show the scales can be completed reliably and that the results correspond well with other methods of screening and assessment.
Dennis207 provides a recent overview of measures to consider for a comprehensive substance abuse assessment. For example, it is recommended that a substance abuse assessment include:
Few assessment measures, however, have been assessed for their reliability and validity with people with concurrent mental health disorders. Carey170 has assessed the reliability and validity of the Time-Line Follow-Back interview among psychiatric outpatients and concluded that it can appropriately be used with this population. Teitelbaum and Carey178 and others35,44 note that the focus on the actual amount and pattern of alcohol and drug use is critical since moderate use of these substances which would not normally be considered
"abuse" can still influence the course of severe mental illness and treatment outcome. Indeed, Drake's research with people with schizophrenia suggests that full-blown alcohol dependence is the exception rather than the rule.
The Addiction Severity Index (ASI)195 is one of the most commonly used standardized assessment instruments in the field of substance use disorders and there is an increasing amount of research on its applicability for people with co-occurring mental health disorders. The general conclusion drawn from most individual studies,213 and research summaries,213 is that many of the sub-scales do not perform as well as to be expected with people who have severe mental illness. In addition to poorer reliability than found with other populations, the ASI has been found to be relatively insensitive to the consequences of lower amounts of substance use; a particular difficulty for people with severe mental illness.44
The ASI has a high acceptance in the field and has been successfully employed in treatment planning, research and program development in addiction treatment centres that have special programs for concurrent disorders, or admit clients with concurrent disorders.214 There is also an adolescent version of the ASI that is available in both French and English.215 After much discussion of the available research on the ASI, it is recommended that the ASI be used cautiously in the assessment of people with concurrent disorders, and particularly with people with severe mental illness. For this particular sub-group (Group 2), the ASI should be supplemented with other information, such as the Time-Line Follow-Back interview,216 clinician ratings,206 or other methods.
A third consistent recommendation for the assessment of people with concurrent disorders is to evaluate their motivation for change, including the stage of change61,217,218 and/or the person's stage in the treatment process.62,218 The
"Stages of Change" model is well-known in the substance abuse field. There are five stages in the change/recovery process:
The measure of the
"stage in treatment motivation" is conceptually related to the stage of change model but developed specifically for people with concurrent disorders (Group 2). The measure is known as the Substance Abuse Treatment Scale (SATS) and complements clinician ratings of alcohol and drug use. The scale places the individual along stages of engagement, persuasion, active treatment and relapse prevention.
To these recommendations of assessing
"stage of change" and/or
"stage of treatment motivation", is added the importance of assessing both these intrinsic motivational factors, and the more extrinsic pressures to seek help (e.g., coercion from the legal system).219,220 Tailoring the treatment plan for people with concurrent disorders based on client stage and motivation, is one of the key principles of an integrated treatment plan as defined by Mueser,45 and Drake and colleagues,64 and is a good example of how the assessment information must be linked to the treatment plan.
Further, there may be many shifts and regression in motivation for change based on:
The issue is that evaluation of motivation may be quite unstable.
Finally, both mental health and substance use assessment must look at the broader psychosocial functioning of the person including such basic needs as housing, access to food, social supports, work, education and training.64 This would also include an assessment of high-risk behaviour for HIV and Hepatitis C (e.g., needle sharing), violence and victimization. The most comprehensive protocol for the assessment and classification of social functioning is the Person-in-Environment System (PIE).221,222 This assessment tool has been developed by the social work profession and is consistent with the broad bio-psychosocial perspective of addictions and mental health. It complements the diagnostic-based assessment process underlying DSM-IV and its predecessors* by focusing separately on factors related to social functioning (e.g., family, friendships, community) and environmental problems (e.g., access to food, housing, employment) and subsequently incorporating mental and physical health diagnosis. Clinician ratings of severity, duration and coping are included in the system.
While there are few published accounts of the application of the PIE assessment process for people with concurrent disorders223 the approach has a high degree of face validity given the important role that psychosocial functioning plays in determining the course and outcomes of concurrent disorders (see subsections below). The length of the PIE assessment process (on average 90 minutes) may limit its application in some settings. However, a computerized version is pending and this should considerably reduce time for administration and scoring. The short version of PIE [mini-PIE] may be scored by the mental health/substance abuse counselor in less than 15 minutes. There is reliability and validity data for the use of PIE in various human services contexts.
Another alternative for assessment of functioning is the Global Assessment of Functioning Scale (GAF).224 The GAF asks a clinician familiar with an individual to rate that person's overall level of psychological, social and occupational functioning on a scale ranging from 1 to 100. Clear and concise anchors are provided for each 10-point range on the scale. The GAF can be completed with reference to varying time periods (e.g., currently, highest level of past year) and it constitutes the operationalization of Axis V of the DSM-IV mutiaxial assessment.46 It is a slightly modified form of the Global Assessment Scale and it can be used with a high level of reliability.224
Best Practice Recommendation
On the basis of a positive screen for either substance use or mental health disorders, a comprehensive assessment is recommended to (a) establish diagnoses (b) assess the level of psychosocial functioning and other disorder- specific factors; and (c) develop a treatment and support plan that seeks to sort out the interaction between the mental health and substance use difficulties for the individual, and work toward a positive outcome for both sets of problems as well as any related problems.
* While DSM accommodates psychosocial stressors and functioning on separate Axes (IV and V) the assessment is limited to two summary ratings of severity and contributes little information to an individual's treatment and support plan.