Mental Illness and Substance Abuse

Does mental illness cause substance abuse addiction or does substance abuse addiction cause a mental illness diagnosis? Does it go both ways?

A complex relationship exists between substance abuse and mental illness. Those suffering from depression, anxiety and other mental illnesses may use alcohol and drugs as self-medication. Unfortunately, though such options may appear to work temporarily, substance abuse is no treatment for any condition; in fact, it often aggravates the problem during severe intoxication as well as in the course of substance withdrawal (NAMI, 2010).

Furthermore, alcohol and drugs can initiate mental illness in persons who are otherwise mentally healthy, while worsening problems in those who are already mentally ill. Active substance users will tend to not follow-through properly with therapy, and are more vulnerable to serious health complications and even premature death. Those having dual diagnosis will also be more prone to violent and impulsive behavior, and less prone to attaining long-term sobriety. Alcohol and drug addicts have a greater likelihood of committing suicide. Such people usually experience severe substance-abuse-related complications, legal problems and physically dependency (NAMI, 2010).

1.2. Scope of the problem

Nearly half the individuals suffering from severe mental illness are also drug/alcohol addicts. 37% of alcohol dependents/abusers and 53% of drug dependents/abusers also suffer at least one mental issue (NAMI, 2010). 359,000 U.S. adolescents (1.4%) aged 12-17 years suffered from major depressive episode (MDE) and substance use disorder (SUD), in 2013 concurrently. Also, in the same year,7.7 million adults (3.2%) in the U.S. (aged 18 and above) simultaneously suffered from SUD and AMI (any mental illness), while2.3 million U.S. adults (1%) simultaneously suffered from serious mental illness (SMI) and SUD (Substance Abuse and Mental Health Services Administration, Centre for Behavioral Health Statistics and Quality, 2014).

1.3. The affected

Affected individuals suffer many serious consequences. Dual diagnosis can cause decision-making, attention and memory problems, thus affecting their daily lives and functioning. Body organs also get affected. Such individuals are more likely to behave violently, refuse compliance with therapy, and not get treated successfully compared to those having only one of the problems- mental illness or substance abuse. Dual diagnosis-related issues impact families, colleagues and friends, as well. Individuals having dual diagnosis are also prone to getting jailed or having no home. About half the homeless individuals suffering from SMI also suffer from SUD. Also, an estimated 16% of prison/jail inmates have both SMI and SUD, and 72% of prisoners with mental illnesses suffer from SUD as well (NAMI, 2010; Langas, Malt & Opjordsmoen, 2011).

1.4. Significance of the problem

Individuals whose co-occurring problems are not treated are more likely to engage in violent acts, to appropriately respond to therapy, and become victims of illness, imprisonment, homelessness and death. Their daily lives and functioning are adversely affected because of issues with decision-making, memory, and attention; substance abuse also adversely affects body organs (NAMI, 2010).

1.5. Relevance of the problem

Several epidemiological and clinical researches have explored the issue of high comorbid mental illness frequency in substance dependents/abusers. These dual disorders have to be given high priority because of the serious repercussions they pose for patients, families, society, and health services. As compared to those who suffer only SUD or SMI, dually-diagnosed individuals experience delayed diagnosis, severe psychopathological problems, lesser treatment compliance, poorer treatment effects, greatly impaired social functioning, increased emergency admissions, greater physical comorbidity, homelessness, unemployment, suicidal ideation, and criminal or violent tendencies. All the above issues highlight the need for more extensive research in this area (Anderson, Ziedonis & Najavits, 2014; Langas et al., 2011).

1.6. Research objective and questions

This review aims at documenting and describing the patterns of comorbidity between SUD and mental disorders in the general population.

1. What are the mental disorders found? How prevalent and severe are they among individuals, in a single hospital catchment area, admitted for the first-time for substance usage, and admitted consecutively to specialist services?

2. What is the average duration of untreated SUD?

3. How prevalent is substance-independent vs. substance-induced depression, as well as other axis I illnesses, in those diagnosed with SUD?

4. Can any differences be found in diagnosis of mental disorder among those using legal and illegal substances?

5. Can any socio-demographic differences be found in individuals using legal and illegal substances?

2. Literature review

Many different correlations exist between SUDs and mental ailments. Comorbidity may be caused by many factors, including coincidence, common neural substrate or genetic vulnerability, lifestyle, environment, self-medication and basic shared origins. Literature normally applies the following terminologies (based only on chronology) to disorders: “primary,” for denoting the ailment that develops first and “secondary” disorder, which is induced; one must bear in mind that these terms don’t necessarily depict causality. More importantly, one must understand that certain ailments are generated by other ailments, while others are independent (Petrakis, Rosenheck & Desai, 2011). A majority of SUD patients report that they experienced mental issues prior to SUD. This, in some instances, may imply that SUD was caused by mental illness (use of substance as self-medication) (Uwakwe & Gureje, 2011). On the other hand, it can also imply that certain mental disorders occur at an earlier age than SUDs. Some mental illness symptoms are short-lived, occurring because of substance withdrawal or intoxication (Whitbeck, SittnerHartshorn, Crawford, Walls, Gentzler & Hoyt, 2014). For example, high occurrence of depression among those diagnosed with SUD may characterize this kind of phenomenon, known as “substance-related artifact hypothesis” (Whitbeck et al., 2014).

High prevalence of comorbidity between mental disorders and SUDs necessitates an inclusive intervention, which concurrently identifies and assesses each ailment, providing necessary treatment. Such an intervention requires comprehensive assessment tools which will not miss identification (Jane-Llopis & Matytsina, 2006). Hence, patients getting admitted to psychiatric therapy must be tested for SUD, and similarly, those seeking SUD treatment must be tested for mental illness. However, it is difficult to achieve accurate diagnosis because of similarities between symptoms of mental illnesses and SUD (e.g. withdrawal) (Lai & Sitharthan, 2012). Therefore, when SUD-diagnosed individuals enter treatment, monitoring them after some interval of abstinence may be essential, for differentiating substance withdrawal or intoxication effects from symptoms of co-occurring mental ailments. Doing so will ensure greater accuracy in diagnosis, facilitating more targeted therapy.

Often, simultaneous SUD and mental illness results in overall poorer physical and mental functioning of an individual and greater possibility of relapse. Dually-diagnosed persons normally frequent hospitals and therapy, but achieve no lasting success. They are also at greater risk of developing physical ailments and tardive dyskinesia, in addition to experiencing more psychotic episodes, compared to those suffering from any one of the disorders. Besides, physicians normally fail to discern mental problems and SUDs, particularly among older adults. Socially, those suffering mental disease are often vulnerable to comorbid ailments because of “downward drift; i.e., mental ailments may force them to live in marginal localities, wherein drug use is prevalent. Also, such people face numerous obstacles in forging social relationships, thus turning to the community of drug users/dependents, where they are more readily accepted. Some individuals prefer being identified as a drug addict to being labelled as mentally-ill (NAMI, 2010).

Extensive evidence can be found, that links SUD occurrence with that of neuropsychiatric ailments (Anderson & Baumberg, 2006); SUDs are found to be strongly associated with antisocial behaviors, mood disorders, conduct disorders, and anxiety disorders (Merikangas, Mehta & Molnar, 1998). Research on comorbidity has, for instance, linked severe dysthymia and depression with oppositional or conduct disorder (Rohde, Lewinsohn & Seeley, 1991), anxiety, antisocial behavior, aggression, and SUDs in teens and younger children (Nurcombe, 1992). Research that doesn’t specifically revolve around children reveals co-occurrence of depression with alcohol dependency and anxiety (Hippius, Stefanis & Miller-Sspahn, 1994), SUDs, smoking, eating disorders (Rohde et al., 1991) and personality ailments (Hammen, 1997). A similar connection exists between substance dependency and symptoms of depression. Those suffering from depression and negative mood conditions will be more inclined to turn to alcohol and cigarettes (Schoenborn & Horm, 1993); their likelihood of quitting is low, while that of relapse is high (if they do quit). Extensive evidence reveals that people who suffer emotional distress, and turn to alcohol to assuage their problem, have greater probability of acquiring alcohol dependency (Kessler, et al., 1996, 1997; Book & Randall, 2002). Research conducted in the U.S. has revealed that more than 12% of individuals suffering from anxiety are also afflicted with alcohol dependency/abuse issues (Grant, et al., 2004). Comorbidity magnitude is strongly and directly linked to increased acuteness of alcohol abuse/dependency (Merikangas et al., 1998).

Cross-sectional epidemiological research (like the National Survey of Mental Health and Wellbeing (NSMHWB) conducted in 2007) is ineffective, when it comes to comprehensively examining hypotheses regarding comorbid disorders’ nature and underlying relationships (Slade, Johnston, Oakley-Browne, Andrews & Whiteford, 2009). While linkages between different groups of mental disorders, as well as between physical and mental disorders can be defined, it is not possible to present any inferences with regards to causality. Development of effective responses is only possible when likely causes are unravelled. Cerda and colleagues (2008) have investigated this topic within longitudinal literature; they put forward the notion that causal relationships are capable of operating both ways between SUDs and mental illnesses, for instance, both depression and conduct disorder intensify the probability of dependency/misuse of substances; when people with conduct and depressive disorders develop SUDs, their condition worsens; and those who develop SUDs can subsequently develop anxiety and depressive illnesses (Teesson, Slade & Mills, 2009; Cerda et al., 2008; Hall, Degenhardt and Teesson, 2008).

Extensive epidemiological research is required to follow up on the above findings and explore causal correlation in comorbidity. A follow-up NESARC (National Epidemiologic Survey on Alcohol and Related Conditions) research that looked into incident disorders and their association with baseline disorders offers a clear-cut example, and vital information regarding the link between the ailments (Grant, Goldstein, and Chou, 2008; Volkow, 2004). The research discovered that presence of certain baseline mental disorders predicted incident disorders in the follow up after 3 years (following demographic variable control). Alcohol/drug dependence and abuse strongly predicted each other. On the other hand, baseline drug and alcohol use disorders didn’t forecast increased mood-disorder occurrence. Baseline anxiety/mood disorders (particularly panic and bipolar disorders) predicted greater risk of alcohol and drug abuse during follow-up analysis (Teesson et al., 2009; Grant et al., 2008).

3. Methodology

3.1. Study design

The research will be conducted in two parts: 1) A realistic cross-sectional diagnostic descriptive analysis of a sample of SUD-diagnosed patients; and 2) A comparative analysis of the 2 key patient groups: (i) those only suffering from alcohol use disorder, and (ii) those in whom SUD is caused by other psychoactive substances (Teesson et al., 2009).

3.2. Sampling

Slade and colleagues (2009) have defined survey techniques, presenting its major findings. The stratified multistage sample taken for the NSMHWB, conducted in 2007, included individuals aged between 18 and 85 years residing in private residences, excluding extremely remote localities. Response rate for the survey was 60%; a total of 8841 participants responded fully.

3.2.1. Unit of analysis

Sample will consist of substance users, who are first-time outpatients / inpatients admitted for specialist psychiatric / specialist addiction therapy. A thorough account of treatment history will be obtained for patients to ascertain that they haven’t previously received specialist treatment; written consent of patients with regards to granting access to their previous medical files will also be taken (Langas et al., 2011).

3.2.2. Number of respondents

The population sample will comprise of 746 adults, tribally-enrolled, and aged between 18 and 85 years; respondents will take part in an 8-wave panel research conducted through 2014-15. Diagnostic interviews were conducted at Wave 1 (with response rate of 79.4%) and waves 4, 6, and 8 with retention rates being 87.7%, 88.0% and 78.5%, respectively. All manuscripts were first approved by the Reservation advisory boards, before publication. Reported sample size was lowered from earlier published reports, as one reserve advisory panel dissolved, thus being unable to review and approve the paper. This reservation resulted in a loss of around 70 cases; however, it didn’t appreciably change analyses results. Diagnostic sample for the report, at the initial wave comprised 672 adults (337females and 334 males).

3.2.3. Access

Since it is a comprehensive assessment, and a majority of participants are expected to be outpatients, several appointments will be needed. Attrition will be prevented as follows: (i) contact information will be acquired from participants, to get in touch with them in case of patient failure to keep an appointment, (ii) new appointments will be scheduled if they agree to it, (iii) interviews may be conducted at any suitable place, with interview time decided by the participant, (iv) patient motivation will be ensured by providing them assurance that assessment results will be sent to them directly, or to the therapist they consult (Langas et al., 2011; Nock et al., 2010; Nunes & Rounsaville, 2006).

3.2.4. Sampling procedure

Participants of the study should be willing to take part and cooperate. Assessment of patients suffering from severe withdrawal, severe intoxication, or severe psychosis will take place after sufficient decline of the severe symptoms, in order to allow them to provide reliable information. It is, however, not compulsory for participants to abstain for some duration or be completely free of withdrawal or psychosis symptoms. If patient assessment hints at an organic brain problem, researchers will study this as well (Nock et al., 2010; Nunes & Rounsaville, 2006).

3.2.5. Sampling method

This research’s effectiveness hinges on comprehensive participant assessment and possibility of locating all patients in a particular catchment area, admitted consecutively for therapy, rather than on number of participants. Sample size estimation for ensuring differences of statistical significance between groups proves to be problematic, as prior prevalence works have differed greatly from one another. Differences between patient groups can be estimated only as qualified guesstimates. In regard to this matter, one may consider this research to be a pilot study, aimed at creating hypotheses for future researches (Anderson & Baumberg, 2006; Teesson et al., 2009; Cerda et al., 2008).

3.2.6. Rationale

A wholly randomised technique will be adopted while selecting sample members, from among users of psychoactive substances, with a previous record of mental ailment.

3.3. Data collection strategy

Basic health-related and socio-demographic information on patients will be recorded through an abridged version of the NEQ (Network Entry Questionnaire) developed by Stanley Foundation. Many major mood-disorder researches have employed this tool; it evaluates stigmas / attitudes related to mental illness (Anderson & Baumberg, 2006). This questionnaire also provides information regarding differentiation of unipolar and bipolar depression. Psychiatric symptoms can be screened using SCL-90’s revised version (SCL-90 is short for 90 question Symptom Check List) (Cerda et al., 2008). Research has proven moderate specificity and high sensitivity for SCL-90 as an instrument for screening SUD patients for mental illnesses. GSI (Global Severity Index) may be utilized for the purpose of measuring total psychological distress. The 9 subscales, however, may not reflect independent dimensions separately (Teesson et al., 2009).

A split version of Global Assessment of Functioning (GAF-F and GAF- S) will also be employed for patient assessment. This tool is highly reliable in the hands of trained researchers. GAF blindly rescores any 10 patients at random, employing all available information, for ensuring its reliability. Diagnostic interviews and clinical judgement will form the base of patient diagnosis, which will be determined as per Diagnostic and Statistical Manual (DSM-IV) text revision, as diagnostic interviews for the study are devised for this definition (Lai & Sitharthan, 2012). A qualified psychiatrist will interview patients via the PRISM (Psychiatric Research Interview for Substance and Mental Disorders), which is a partly-structured interview that covers present and lifetime dependence/abuse diagnoses, twenty axis I ailments, and most prevalent personality disorders that are seen in substance abusers (borderline and antisocial disorders). The interview was developed for improving reliability of comorbid mental disorder and SUD diagnoses.

3.4. Measurement

Version 3.0 of the Composite International Diagnostic Interview (CIDI), developed by the WHO (World Health Organization) will be used for assessing mental illness. CIDI is diagnostic interview, wholly structured and administered by nonprofessional interviewers trained for the purpose of the study (Lai & Sitharthan, 2012). The study covered sixteen mental disorders: anxiety disorders (generalized anxiety disorder, panic disorder, separation anxiety disorder, phobias and post-traumatic stress disorder), impulse-control disorders (conduct disorder, oppositional defiant disorder, intermittent explosive disorder and hyperactivity / attention-deficit disorder) substance use disorders (illicit drug and alcohol dependence/abuse) and mood disorders (bipolar disorder, major depressive disorder, and dysthymic disorder). A clinical reassessment research indicated an overall good consistency between diagnoses generated by CIDI and those generated by the use of the Structured Clinical Interview’s (SCID) research version (Nock, Hwang, Sampson & Kessler, 2010; Lai & Sitharthan, 2012).

3.4.1. Conceptualization

In some ways, DSM-IV conditions are unclear; this may compromise a study’s validity and reliability. DSM-IV’s definition of independent or primary disorder doesn’t explicitly state the conditions under which an existing disorder may be categorized as primary (e.g., whether it has to take place in a period of a minimum 30-day abstinence; whether the comorbid disorder is applicable for independent diagnosis despite occurring during a previous abstinence period; whether past episode took place in the course of abstinence). Furthermore, criteria don’t explain whether a partially-remitted or full syndrome should occur. ‘Substance-induced’ is also not defined clearly; its definition only states that certain disorder symptoms (like anxiety or depression) are present, eliciting confusion regarding whether major depression and other such full syndromes are required. ICD-10 criteria stipulate the latter condition. In the context of symptom, DSM-IV is vague regarding how one can ascertain whether symptoms surpass usual substance effects; also the lists of DSM-IV symptoms for different substance withdrawal and intoxication syndromes are not always comprehensive (Nunes & Rounsaville, 2006).

3.4.2. Operationalization

PRISM was developed by Hasin and coworkers after analyzing the reasons behind SCID’s poor reliability. PRISM defines substance-induced depression accurately. This necessitates meeting of full syndrome of major depression (minimum5 symptoms); also, each symptom should exceed the substances’ usual effects. PRISM classified around half the hospitalized, dual-diagnosed inpatients from a clinical patient sample as ‘substance induced’ (Nunes & Rounsaville, 2006). Follow-up after a year revealed substance-induced depressive disorders to be predictive of suicidal tendencies and failure to remit in SUD-diagnosed individuals. Usual substance effects were not coded, and were discarded. Furthermore, a study which modified SCID and added some PRISM features to it revealed that around 33% of baseline major depression cases out of a clinical patients’ sample transformed into independent depression after a year; i.e. the follow-up study showed depression persisting during abstinence intervals of minimum 30 days (Nunes & Rounsaville, 2006). When these data are taken collectively, they indicate that defining substance-induced depression more rigorously (full syndrome requirement, as well as an effort towards operationalizing exceeding of usual effects) leads to a syndrome having reasonably clear predictive and treatment effects, in addition to one which may, over time, transform to independent or primary depression. Other research tools which have operationalized ‘substance-induced’ depression vs. independent depression difference include the AUDADIS (Alcohol Use Disorders and Associated Disabilities Interview) (Jane-Llopis & Matytsina, 2006), formulated for lay interviewers for the purpose of two major community-based researches; the NESARC, which showed very low substance induced depression prevalence, thereby classifying most major depression cases as primary or independent (Petrakis et al., 2011); the SSAGA (Semi-Structured Assessment for the Genetics of Alcoholism) developed for a collaborative research on alcoholism’s genetics; and the NLAES (National Longitudinal Alcohol Epidemiologic Study). One cross-sectional research that based itself on COGA (Collaborative Study on the Genetics of Alcoholism) showed independent depression to be linked to several features which indicated more likelihood of acquiring true affective illness (like depression in the family, prior suicide attempts, etc.) when compared with substance-induced depression. A related research suggested that independent depression was linked more closely with those possessing depressive cognitive afflictions.

3.4.3. Reliability and validity

This is a unique study — it employed codified data sets of hospital inpatients, with data entry performed by qualified clinical coders. Coding quality differs among coders; nevertheless, Henderson and colleagues (2006) conducted a hospital data audit and revealed 85% overall accuracy in 3-digit level data coding. Major procedures and diagnoses had good-to-excellent coding quality. The authors reveal that when the nature of analysis is considered, administrative data is capable of providing highly consistent population-based estimations of rates of hospitalization.

4. Protection of human subjects

The Regional Committee for Medical Research Ethics has approved the project, which will be conducted as per Declarations of Madrid and Helsinki. No procedures in the study pose health risks to patients. All interviews and screening tools are internationally validated and accepted, and have been employed by previous studies across the world. Patients are not generally averse to thorough examinations, nor do they consider examinations to be overly strenuous. Written and oral information regarding the study will be communicated to all subjects prior to obtaining their written consent from them. Refusal of any patient to participate in any assessment will be respected. If most interviews are refused by a subject, researches will understand that the subject doesn’t wish to participate. Research will be tested for bias by recording some unidentifiable, basic information on patients unwilling to participate; e.g., substance type used by the patient, sex, age (Nunes & Rounsaville, 2006; Langas et al., 2011).

Patients’ biomedical and other examinations may possibly reveal information which makes it necessary to provide adequate care and avoid compromising patient health. Such information, with the permission of the patient, will be forwarded to the GP or therapist in charge of treating the patient. If patients do not desire to disclose this information to their GP/therapist, their wish must be respected. Identification of life-threatening conditions of psychosis, depression, or intoxication will be followed by suggestions for suitable treatment. Patients aged 16-18 years can give full consent with regards to participation in the research. In case a problem requiring treatment is encountered, for which the young patient is not entitled to offer consent, or patient’s parents have to be contacted for exercising parental responsibility, information regarding the issue will be passed on to the patient’s GP or therapist (Langas et al., 2011; Nock et al., 2010).

All adult patients (aged 18 years and above) will be inquired as to whether they permit videotaping of their interview. If a patient refuses, his/her wish will be granted without consequence, and if he/she accepts, a separate agreement statement will have to be signed by the patient. The recording’s purpose, video use, erasure and security will be explained. Permission for contacting patients within a decade for participation in follow-up research will be obtained. This participation in follow-up will require a new written statement of consent, which will be signed during follow-up study. Patients are free to refuse giving their consent in this regard (Langas et al., 2011).

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