Modern psychopharmacology, at the turn of last century, was instrumental in the discovery of certain medications that could address specific psychiatric symptoms in major, chronic mental disorders. One of the most prominent discoveries at that time was that of the first generations of antipsychotic medications to treat psychotic thought disorders, such as schizophrenia. These mental disorders can be characterized by a variety of symptoms which reflect disordered thinking, including hallucinations, delusions, disorganized speech or thought processes, and disorganized or catatonic behavior.
The advent of antipsychotic medications during the 1950s is thought to be one of the most relevant milestones in the treatment of schizophrenia. The first generation of antipsychotic drugs have been implicated in reducing the rates of hospitalization as well as psychiatric relapse (or reoccurrence of symptoms severe enough to disable an individual from being able to care for themselves). Of the antipsychotic medications available, the phenothiazines and butyrophenones are the most commonly prescribed for schizophrenia. While the effects of these medications can vary across individuals, they are most noteworthy for addressing what are known as the positive symptoms of schizophrenia.
Learn more about Schizophrenia with this 11-minute CrashCourse.com video:
What are the positive symptoms of schizophrenia that are best addressed by antipsychotic medications?
While the term schizophrenia literally means “split mind,” it is best thought to characterize the split that an individual with this disorder has with the perceptual reality around him or her. Positive symptoms are those irrational behaviors engaged in by individuals that are overt, observable, and considered to be classically associated with the diagnosis of schizophrenia. Examples include florid hallucinations, disorganized and apparently purposeless behaviors, disorganized speech, and delusions. These symptoms have to persist for a minimum of six months’ duration to meet the diagnostic threshold for this mental disorder.
A delusion is a false belief that is strongly held by an individual, despite evidence in the environment and beliefs held by all those around them to the contrary. For individuals who have been diagnosed with schizophrenia, delusions are often characterized by persecutory beliefs such as the individual thinks they are being tricked or spied upon, or referential beliefs such as the false belief that an individual is receiving special messages that are directed to them individually. Regardless, these beliefs are far outside the realm of ordinary human experience, illogical, and without direct evidence to support their belief.
Hallucinations are false sensory perceptions that can occur with any sensorimotor modality (e.g., sight, feeling), but are typically associated with hearing (auditory hallucinations). Hearing voices that are divisive or threatening in nature is often how these hallucinations are manifested. Disorganized speech can be characterized by expressive language that is often tangential or ”loose” in terms of the associations that an individual makes; the content of speech is often not tied to an obvious, immediate environmental context. Individuals who exhibit this type of language may talk in a manner where they seem to go from one topic to the next without appropriate social transitions and without making any sense to the listener.
At the extreme, individuals can exhibit nonsensical “word salad” in their speech and use language that could be described as unintelligible gibberish. Unusual or disorganized behaviors can include being unable to care for oneself in an age-appropriate fashion, being unpredictably agitated, or engaging in repetitive and apparently purposeless behaviors.
By contrast, negative symptoms as they relate to a diagnosis of schizophrenia are subtler in nature and typically involve the restriction or a limited range of intensity or expressiveness of emotions and behaviors seen in a typical individual. Examples include a lessening or ”flattening” of emotional responsiveness, which could include facial expressions as well as general, emotional expressiveness, alogia (poverty of thought and speech), and avolition (reduced goal-directed behavior). When compared to positive symptoms, antipsychotic medications have not demonstrated as much of an effect on these types of symptoms in the treatment of schizophrenia.
Current research generally finds that while schizophrenia has a significant genetic component, it also typically requires the presence a certain psychosocial risk factors and a lack of resiliency factors in tandem for it manifest itself in an individual. That is, it does not manifest itself in adulthood with a one-to-one correspondence as might be expected if it were a dominant genetic trait. Rather, there needs to be a genetic propensity in place in the individual, coupled with the right mix of psychosocial stressors in their life, which will elicit the manifestation of the disorder.
What is the primary neurochemical theory behind the drug treatment of schizophrenia?
With regard to drug effectiveness, there are several neurochemical theories pertaining to the mental disorder of schizophrenia. The most well-known of these, and the one that has received the most empirical support, is the dopamine hypothesis. Simply stated, it contends that schizophrenia occurs because of excessive levels of the neurotransmitter dopamine at the receptor sites in the brain that produce random and overly rapid (and maladaptive) transmission of neural impulses.
Evidence from drug research that supports the dopamine hypothesis includes the observation that when people with schizophrenia our prescribed phenothiazines, which are believed to block dopamine receptors, that positive symptoms of schizophrenia are significantly reduced. Conversely, when people with a low threshold for psychotic-like symptoms are given medications such as amphetamines that are known to increase dopamine at the receptor, under controlled situations, the severity and frequency of delusions, hallucinations, and other psychotic symptoms increase significantly.
Some individuals with the diagnosis of schizophrenia may exhibit motor disturbances, but these can, in fact, be due to the use of antipsychotic drugs as an unwanted side effect. In fact, other problems which can arise from taking antipsychotic medications (especially first generation ones) include an increase in some of the negative symptoms which have been previously mentioned as well as the development of rather severe motor side effects, most notably tardive dyskinesia, which is characterized by involuntary jerky motions of the face and lips, rocking, and an unsteadiness when walking. As is the case with the treatment of many chronic and severe mental disorders, noncompliance with ones prescribed medication regimen can also be problematic.
As you have studied from previous weeks, it is often the case that a multimodal treatment is best with regards to treatment outcome for a mental health disorder like substance dependence. This is certainly the case with regard to the treatment of schizophrenia as well. Some research has indicated that combining family therapy with antipsychotic medication management leads to better treatment outcomes for individuals when compared to pharmacologic treatment alone.
In addition, the provision of family therapy has been shown to enable the prescribing physicians to utilize a lower dose of these strong antipsychotic medications without a greater chance of relapse when treating people as compared to a medication-only treatment plan that often requires a higher dose of the same drug. Finally, the effects of antipsychotic medication are heightened when patients whose symptoms are severe enough to merit hospitalization also receive concurrent social skills training that helps them improve their interpersonal communication skills through modeling experiences and practice role playing exercises.