The prevalence of substance use disorder, excluding cigarette smoking, in individuals with schizophrenia is about 40%, nearly 5 times greater than the average population. Studies suggest alcohol is the most common substance of abuse next to marijuana. Schizophrenia and comorbid alcohol use disorder (AUD) is associated with a variety of poor outcomes including depression, homelessness, victimization, and violence. Unlike AUD in non-mentally ill populations, alcoholism here can lead to relapse into psychosis and a host of other problems. A review of the literature shows that such a unique population poses new challenges in treatment. There are many theories that posit an explanation for increased risk of developing AUD in schizophrenia, but there is little agreement as to which best accounts for the high comorbidity. Rather than a reductive approach that would seek to pinpoint one single focus in order to modify use, comorbidity may be better addressed as a concert of biopsychosocial factors.
Studies suggest that, much like in the general population, alcohol is the most common substance of abuse among test subjects with schizophrenia (SZ), followed by cannabis and cocaine. 47 percent of those diagnosed with schizophrenia or schizophreniform disorder have met the criteria for diagnosis of substance abuse disorder at some point in their lives and 33.7 percent met the criteria for alcohol use disorder (AUD). While there is no definitive research on how many are polysubstance users, using multiple substances is common among this population and those who abuse alcohol are at a much greater risk for developing polysubstance abuse disorder. Not only is alcohol easier to obtain because it is a legal substance, it is shown to have less impact on cognitive deficiency in SZ than other substances of abuse.
Alcohol use is a predictor for non-remission of SZ symptoms. It is linked to increased chronicity, medication noncompliance, and poor treatment adherence and retention. It is associated with relapse into active psychosis, and higher rates of homelessness, incarceration, and hospitalization. It is a particularly expensive problem; SZ patients who abuse alcohol miss more appointments and use more crisis-oriented resources than those who do not. Alcohol abuse can lead to neuronal damage resulting in cognitive deficits not unlike the negative cognitive symptoms of schizophrenia.
People with severe mental illness are more sensitive to the effects of psychoactive substances. Only a small amount of alcohol by someone with severe mental illness exacerbates the illness and affects psychosocial adjustment (i.e. problems with relationships, behavior, housing, and finances). Alcohol abuse can worsen positive symptoms, and mixing alcohol with antipsychotic medication can cause it to be less effective. Increased sedation one feels from mixing antipsychotics with alcohol is believed to be a reason for medication noncompliance. Furthermore, neuronal damage caused by alcohol abuse can make patients less responsive to antipsychotic medication.
Overall, alcohol abuse in SZ compounds the risk of relapse into psychosis. After each active phase of the illness residual (negative) symptoms may increase while ability to function normally decreases. The more relapses into active phase psychosis means a decrease in the possibility of recovery.
Risks seen in this population are not entirely unlike those seen in the general population. They have more legal, medical, marital, and occupational problems than those without comorbid AUD. But there is a greater risk of homelessness, depression, victimization, and violent behavior. Impulsivity and impaired cognitive functioning can result in aggression, self-harm, accidents, and increased risk of sexually transmitted diseases. A study by Isohanni et al. found that men with SZ who abuse alcohol are about 25 times more likely to commit a violent crime than men without SZ, and 10 times more likely to commit a violent crime than a man with SZ who does not abuse alcohol.
SZ patients with comorbid AUD begin using alcohol at the same age as the general population. They report using for the same reasons that most young people do: for the enjoyment of the feelings associated with intoxication. A socioenvironmental model calls to question the environmental factors that contribute to the development of AUD. Circumstances in SZ are associated with the development of alcohol use disorder including depression, decreased opportunity, downward drift, low socioeconomic status, poor access to healthcare, mental illness stigma, post psychotic depressive disorder, and belonging to a family with high expressed emotion. This places SZ and AUD near to each other on the social spectrum.
There are several biological theories that posit explanations but there is little agreement as to which best accounts for the high comorbidity. The neurotransmitter GABA has been implicated in the pathogenesis of schizophrenia. Drugs that enhance GABA in the prefrontal cortex have been used to treat schizophrenia. Similarly alcohol has enhancing effects on GABA transmission. Given its inhibitory nature GABA is responsible for stress and anxiety reduction. This evidence would indicate that individuals with schizophrenia may be using alcohol to enhance GABA activity .
Abnormalities in the brain that characterize SZ are thought to facilitate positive reinforcement affects of substance use. Dopaminergic problems are a core feature of schizophrenia; antipsychotic medications are largely dopamine antagonists. Dopamine plays an important role in cognition, memory, attention and especially reinforcement. It powers the reward system of the brain giving the sensation of pleasure when something is accomplished and providing motivation. Dopaminergic problems in schizophrenia are responsible for the negative symptom of anhedonia. It has been suggested that alcohol misuse in schizophrenia could be an effort to feel pleasure.
Both GABA and dopamine theories support a self-medication explanation of AUD in SZ. Self-medication hypothesis posits alcohol abuse is related to the desire to alleviate SZ symptoms, dysphoria associated with antipsychotic medication, or embarrassment/disappointment associated with medication side effects, such as movement disorders and weight gain. There is evidence that most of the dually-diagnosed have higher levels of symptomatology in comparison to those with schizophrenia and no history of AUD On the other hand self-reports show that most patient with SZ drink for hedonistic reasons, strictly “to get high,” rather than self-medication motives.
There appears to be a cluster of factors, biopsychosocial contributions, that lead to AUD and many more that obstruct treatment. Discrepancy between self-reports versus collateral reports and CAGE tests lead healthcare professionals to believe patients are either misinterpreting the extent of their use or seeking to conceal it. It can be difficult to assess and treat individuals for dual diagnosis due to symptoms of the illness. Anosognosia can lead to ambivalence about drinking problems or concerns. Anhedonia can make it difficult for this population to experience the benefits of decreased drinking. Avolition is a stumbling block to engagement in treatment. Alogia makes it hard for patients to unpack their thoughts surrounding use.
Because most patients with SZ are likely to be found in psychiatric facilities, rather than addiction treatment facilities, they are less likely to receive the help they need than other dually diagnosed populations. Typically they are released when their schizophrenia symptoms attenuate or they are discharged as soon as their AUD is discovered. Treatment for AUD in SZ usually focuses on moderation rather than abstinence. However less than 5% of those with severe mental illness are able to sustain moderation of use without negative consequences and are unable to return to social or recreational use. Adherence to abstinence programs is much better when the program has a dual-diagnosis orientation rather than a substance abuse orientation. As seen in most dually-diagnosed populations, it is clearly important that the special circumstance surrounding their mental illness be taking into consideration in treatment.
Studies show stress to caregivers in much higher with dual-diagnosis patients. Furthermore caregivers tend to turn a blind eye to alcohol misuse because changes in routine, stress, and depression can lead to a psychotic episode. In order to maintain a stable environment they shy away from trying to decrease or even monitor use. They are not interested in approaches like coercion and ultimatums to decrease alcohol consumption. However family interventions in AUD have shown greater success in SZ cases. In fact, the participation of the caregiver-parent, in this case the mother, in treatment is a strong predictor for successful initial engagement in dual-diagnosis treatment, especially for those who reported an improvement in their relationships with the patient. This shows the importance of family motivation in getting patients engaged in treatment. The level of family engagement in targeted treatment and economic support both have a positive effect on outcome. Even the number of caregiver hours, time spent with the patient, positively correlates with reduction of substance use and is also associated with a higher rate of abstinence.
Cognitive behavioral approaches have shown good results when the focus is on skills training specific to this population, including social skills training, and sensitivity towards the cognitive deficits that can accompany the illness. A new approach called Behavioral Treatment for Substance Abuse in Schizophrenia (BTSAS) combines monthly MI, training in drug refusal strategies, drug education, and urinalysis (for monetary compensation). It is designed to reduce the load on higher cognitive functions, memory, and attention. On the other hand, these sessions are highly structured and flexibility has shown the greatest success with this population.
Self-efficacy is crucial to addressing AUD and it may be hard to come by in schizophrenia. They are dependent on medication to manage their mental illness; it is widely accepted that medication is necessary in schizophrenia treatment. This seems to affirm the idea that the individual is not in control. Meanwhile, in the case of AUD, it is necessary to empower the client to make a change. If alcohol is relieving feelings of helplessness, a pattern of reinforcement is established.
Graeber et al. (2003) found that motivation interviewing (MI) has more significant and lasting effects on this population than an educational intervention (typically used in ER settings). Those in the MI condition reported fewer drinking days and higher rates of abstinence. An integrated program that combined weekly MI with family or caregiver interventions and cognitive behavioral therapy had even greater improvements in clients’ general functioning and an increase in the rate of abstinence at 12-month follow up. It bears mentioning that these participants were particularly symptomatic at the time of participation, and they were not seeking treatment for their substance abuse when they enrolled.
Because avolition and ambivalence can play a large role in SZ, some motivation-based treatments (MBT) attempted to develop methods to enhance readiness to change in this population. A four-session MI module was designed for this population including reflective listening, affirmation, and an emphasis on autonomy, control, and responsibility. The feature of alogia can make it difficult to get the client to become an agent of change. This study used something experimenters called the “Columbo technique” where clients were asked to reflect and unpack statements they made while the therapist expressed a certain level of ignorance so that the client felt they were “educating” the therapist. It’s a method of empowerment that adequately elicited elaboration from the client. Furthermore, each session was flexible to the needs of the client on that particular day. For instance, the pace was adjusted depending on whether the client wished to move through activities quickly or slowly. Additional meetings were available in the event that the client was in crisis. Clients who completed the 4 sessions reported it as a helpful and positive experience.
The most effective intervention in the case of SZ and comorbid alcohol use disorder is likely an integrated approach that combines MI, skills training, and family intervention. Because symptoms and antipsychotic medication can mask the level of alcohol use and benefits of decreased use motivation must be bolstered on a regular basis. MBT can enhance readiness to change, increase commitment, develop a change plan, and uncover sources of potential external motivation like family or employment. AUD programs must reconsider their emphasis on abstinence when dealing with this population because many patients may not be able to meet the commitment. Erring on the side of harm reduction, therapists must respect the autonomy of the client and their right to choose their own course of action. Advice giving should be held off until a final session. Next Steps, Personal Strivings, and Expectancy Scales review in MI can be moved to the middle or end of the intervention in the event that the client needs to make more concrete steps at the beginning of treatment. Emphasis should be on assessing readiness to change, meeting the client where they are with their alcohol use, and consistent motivational empowerment to maintain the goal of reduced alcohol use.
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