Do People with Mental Illnesses Such as Schizophrenia Self-Medicate with Drugs?

Do People with Mental Illnesses Such as Schizophrenia Self-Medicate with Drugs?

Depending on your perspective, either drug use can cause schizophrenia, schizophrenia can lead to drug use, or both. The link between substance abuse and mental illness is well-established, with around 50 percent of people with a severe mental health issue also abusing substances, according to the Journal of the American Medical Association. The nature of this link is less clear, however and some have suggested that mentally ill people turn to drugs for relief. There are several alternative explanations, but on first glance it seems plausible that self-medication might be a factor.

The Self Medication Hypothesis

The self-medication hypothesis was first developed by Edward J. Khantzian, who postulated that people with psychological issues abuse drugs as a method of controlling their symptoms (or the side effects of prescribed medication). Khantzian worked with heroin addicts, and started to notice that many of them had problems with aggression prior to using drugs. When questioned about it, they told him that heroin helped to calm their anger and subdue feelings of restlessness. This lead to the formulation of his idea, and he went on to develop elaborations of it to suit other drugs. For example, cocaine abuse was said to result from a desire to combat depression and hypomania. He went on to declare that several personality traits are predictors for substance abuse.

The benefits of this model are that it seems to explain why people use drugs (and often relapse) and also why not everybody who takes them becomes addicted. Many people have extended this general idea to include mental illnesses such as schizophrenia, and the idea that some individuals choose take certain substances to alleviate their symptoms. In many cases, the drugs actually make the symptoms the individual experiences considerably more severe. In schizophrenia, most drugs exacerbate the symptoms, aside from opiates, which may actually be beneficial.

Statistics on Mental Illness and Addiction

Although the self medication hypothesis is hotly debated, a lot of research does support the notion that people with mental health conditions are more likely to abuse substances. For example, the Journal of the American Medical Association reports that 53 percent of all drug users have at least one serious mental illness. Likewise, 37 percent of alcoholics also have a condition, and 29 percent of all people diagnosed with a mental illness abuse alcohol or drugs. In schizophrenics, the rates of smoking are three times that of the general population, 75 to 90 percent compared to 25 to 30 percent.

Criticisms of the Self-Medication Hypothesis

Many people have criticized the self-medication hypothesis on the grounds that the drugs used do not produce a relief in the symptoms. The majority of studies which look at the effects of various drugs on schizophrenia symptoms, for example, show little to no effect on the symptoms of the condition. Likewise, other research shows that there are still higher rates of substance abuse in psychosis patients who have just had their first episode. There are also studies which show a link between drug use and the likelihood of developing mental illness, which may mean that drugs precede illness, and not vice-versa.

These criticisms aren’t as strong as they first appear. Firstly, it doesn’t necessarily matter that the drugs don’t have much of an objective effect on the symptoms of the conditions. The perception of the individual is important. In the 19th century, brandy was frequently administered as a medication. We now know that this isn’t an effective treatment, but it was still used as “medicine” in that context. Similarly, somebody with a stress disorder might think that smoking marijuana makes them feel better, but in actuality it is ignoring the real issue and ultimately making things worse. They are still self-medicating, just poorly.

The other points raised don’t really address the true core of the hypothesis. Mental illnesses don’t manifest at the moment they’re diagnosed, or even on the first psychotic episode. Many of them are believed to have genetic links, or at least a close association to childhood events. The condition is going untreated when it hasn’t been diagnosed, so self-medication is surely more likely in these circumstances. It’s also generally assumed that drugs only cause mental illness in people who are susceptible to it, or who already have a dormant issue, so it can’t really be thought of as a cause, just a catalyst.

Alternative Explanations

There are numerous other potential reasons that more people with mental health problems abuse substances. One of the most compelling is that the physiological differences in the brains of people suffering from mental illnesses are in some way linked to the actions of the drugs. For example, schizophrenics are said to have major differences in the dopamine-related reward circuitry of the brain. The vast majority of drugs increase dopamine levels, so this could explain the predisposition to addiction.

Overall, the self-medication hypothesis is fairly strong, but doesn’t have the scientific weight of the neurological explanation. If similar links were uncovered between dysfunctional systems and drugs of abuse, it may be a compelling model of addiction. However, it’s important to remember that not all drug abusers develop a mental illness and not all mentally ill people develop addiction. There are clearly other factors at play, but it seems hard to deny that self-medication doesn’t play a part in some cases.


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