The most common mental health disorders associated with Substance Use Disorders (SUDs) are depression, anxiety, bipolar disorder, and antisocial personality disorder. While both SUDs and mental health disorders are of significant concern, dual diagnosis patients typically require more medical, psychiatric, and social support than those diagnosed with a single disorder. One issue that healthcare providers are particularly cognizant about is that dual diagnosis patients tend to be more inclined to commit self-harm.

Dual diagnosis patients also experience higher rates of homelessness and tend to face more medical, financial, and legal challenges.Previous research on psychiatry and addiction has indicated that mental health illnesses and substance use disorders share many similar symptoms, and a growing body of evidence has shown that one disorder has the ability to influence the development and treatment outcomes of the other. Thus, the treatment of dual diagnosis patients has always been focused on addressing both disorders simultaneously, requiring the expertise of various healthcare professionals.

Many biological and environmental factors affect the development of dual diagnosis. The genetic makeup of every individual can predispose them to both SUDs and mental health disorders. Alternatively, the vulnerability of some individuals to developing one condition disproportionately increases their chance of acquiring the other condition.On the other hand, environmental triggers such as stressful life events, trauma, and prolonged exposure to drugs and other substances also increase an individual’s susceptibility to developing both an SUD and a mental health disorder.

Many patients with dual diagnosis suffer different health, social, emotional, and financial problems. Both mental health illnesses and SUDs negatively influence an individual’s capability to make healthy choices for their body, and poor health-seeking behavior affects their immune system and increases their risk to develop medical conditions. Moreover, dual diagnosis also adversely impacts a patient’s personal relationships. Dealing with both a mental health disorder and an SUD can be burdensome and painful not only for the patient but also their loved ones. The long hours of treatment can be emotionally exhausting, and the financial burden of getting adequate treatment for both conditions can prove too much to bear.

Over the last several years, the need for a comprehensive and individualized treatment of dual diagnosis has been emphasized by many researchers and clinicians. Because of the complex relationship between substance use disorders and mental illnesses, there must be a focused treatment for each of the existing illnesses to achieve optimal outcomes for the patient.The first and most important step in dual diagnosis rehab is making an accurate diagnosis. While a lot of substance use disorders and mental health illnesses are treated using similar psychosocial and medical interventions, performing an accurate diagnosis allows for individualized treatment regimens. The most effectual treatments remain those which are recommended for the individual disorders, and coordination of these treatments produce successful outcomes.Three models for managing dual diagnosis have emerged over the past few years: sequential, parallel, and integrated.

Sequential treatment is when one illness (either the psychiatric or substance use disorder) is treated first before the other. Historically, this has been the most common approach to the treatment of dual diagnosis.Some clinicians believe that the treatment of the psychiatric disorder takes precedence over that of the substance use disorder, while other clinicians believe otherwise. Most clinicians, still, argue that the severity of the disorders determines the sequence of treatment, recommending that the more severe conditions be treated first. In practice, however, the treatment sequence depends on the current condition of the patient. Immediate psychiatric support must be given to patients exhibiting acute episodes of a major psychiatric problem such as psychosis, mania, or suicidal behavior.

Parallel treatment, on the other hand, refers to the simultaneous treatment of both the psychiatric and substance use disorders at different facilities. For example, patients who have problems with alcohol dependence may receive psychosocial interventions such as cognitive-behavior therapy and support group therapy at an addiction center while undergoing outpatient pharmacological treatment at another facility.The major setback of this approach is the restricted collaboration between caregivers. Because of the variable coordination between the facilities, there is a possibility for the patient to receive conflicting advice and instructions.Sequential and parallel treatment may be most effective for patients who have severe manifestations of one disease compared to the mild symptoms of the other.

Of the three models, the integrated model is what is presently widely accepted and used. The integrated model emphasizes the importance of having the same team of clinicians treat the SUD and mental disorder simultaneously. The clinicians assume the responsibility of carefully selecting individual interventions for each disorder and integrate them so that they form a continuum of a patient-centered treatment program. Moreover, delivery of these interventions in the same setting allows for better collaboration among the caregivers.

The major limitation of this approach, however, is the tendency of the clinicians to over-treat the psychiatric disorder and inadequately treat the SUD in patients seeking treatment for the psychiatric manifestations of the SUD. Still, integrated treatments offer many benefits for the patient, such as less cost, reduced sense of isolation, and better compliance because of the streamlining of the treatment programs.

The goal of pharmacologic interventions used in dual diagnosis is to manage symptoms associated with the psychiatric and substance use disorders. Medications used in the treatment of substance use disorders are typically aimed at alleviating withdrawal symptoms, reducing cravings, and preventing relapse.

Anxiolytic medications like benzodiazepines are appropriate to control anxiety disorder and may also be used to minimize alcohol withdrawal symptoms. Imipramine, a tricyclic antidepressant mainly used in the treatment of major depressive disorder, was also found to be effective in reducing opioid cravings. Some evidence also supports the effectiveness of naltrexone in treating schizoaffective disorder and reducing heavy drinking of alcoholic patients.

The treatment of dual diagnosis works much like the treatment of other psychiatric disorders, involving a multidisciplinary team comprising psychiatrists, social workers, counselors, and psychologists.Different modalities of psychosocial interventions are currently being used in the treatment of dual diagnosis. These include behavioral therapies such as motivational interviewing, relapse prevention counseling, and cognitive behavior therapies. These interventions can be administered either alone or in combination, and using these interventions together with pharmacological support significantly improves the patient’s treatment outcomes. Newer modalities are also being presently studied and have shown great potential in dual diagnosis rehab, including mindfulness-based approaches for stress reduction (MBSR) and relaxation techniques.

One of the main challenges in the management of dual diagnosis is the tendency of caregivers to focus treatment on one disorder alone, which is more often the mental illness, rather than treating both disorders with equal attention. The standardized treatment being offered at some mental health centers—with predefined outpatient “treatment packages”—greatly hampers the goal of managing dual diagnosis. Because the treatment packages are typically designed for patients who only have mental health disorders, problems arise when these treatment packages are used even for patients with comorbid SUDs.

A previous study even concluded that some patients are refused treatment even from these mental health centers because of their comorbid SUD.Another challenge in the treatment of dual diagnosis is the non-collaboration between the health professionals who are providing treatment for each disorder. Many dual diagnosis patients consult with different health professionals for each condition, but the lack of communication between these care providers give rise to problems such as overlapping treatment modalities and differences in opinions and recommendations with regard to management.

Perhaps the greatest challenge in the management of dual diagnosis is the patients’ adherence to their treatment regimen, a problem more prominent among patients from outpatient rehab centers. This is probably because of the intricately designed treatment programs with rigid schedules and the assorted list of medications the patients have to take for their condition.

Inpatient treatment clients are more likely to comply with their treatment regimen because they have a team of caregivers who supervise their care; outpatients, on the other hand, lack this kind of guidance. In addition, because of their co-occurring mental health disorders, many dual diagnosis patients find it difficult to keep up with their treatment programs. This poses a threat to the effectiveness of their treatment.