¶ … 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...

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…