Long established as the preeminent source in its field, the eagerly anticipated fifth edition of Dr Stahl's essential textbook of psychopharmacology is here! With its use of icons and figures that form Dr Stahl's unique 'visual language', the book is the single most readable source of information on disease and drug mechanisms for all students and mental health professionals seeking to understand and utilize current therapeutics, and to anticipate the future for novel medications. Every aspect of the book has been updated, with the clarity of explanation that only Dr Stahl can bring.
Psychosis, Schizophrenia, and the Neurotransmitter Networks Dopamine, Serotonin, and Glutamate
Psychosis is a difficult term to define and is frequently misused not only in the media, but unfortunately among mental health professionals as well. Stigma and fear surround the concept of psychosis, sometimes using the pejorative term “crazy.” This chapter gives a general description of psychotic symptoms and explores the major theories of how all forms of psychosis are linked to the neurotransmitter systems dopamine, serotonin, and glutamate. An overview of specific psychotic disorders, with an emphasis on schizophrenia, is presented here but does not list the diagnostic criteria for all the disorders in which psychosis is either a defining feature or an associated feature. The reader is referred to standard reference sources such as the DSM (Diagnostic and Statistical Manual of the American Psychiatric Association) and the ICD (International Classification of Diseases) for that information. Although schizophrenia is emphasized here, we will approach psychosis as a syndrome associated with a variety of disorders that are all targets for the various drugs that treat psychosis and that will be discussed in Chapter 5.
Psychosis is a syndrome – that is, a mixture of symptoms – that can be associated with many different psychiatric disorders, but is not a specific disorder itself in diagnostic schemes such as the DSM or ICD. At a minimum, psychosis means delusions and hallucinations. Delusions are fixed beliefs – often bizarre – that have an inadequate rational basis and can’t be changed by rational arguments or evidence to the contrary. Hallucinations are perceptual experiences of any sensory modality – especially auditory – that occur without a real external stimulus, yet are vivid and clear, just like normal perceptions, but not under voluntary control. Delusions and hallucinations are the hallmarks of psychosis and are often called the “positive symptoms” of psychosis. Psychosis can also include other symptoms such as disorganized speech, disorganized behavior, gross distortions of reality testing, and so-called “negative symptoms” of psychosis, such as diminished emotional expression and decreased motivation.
Psychosis itself, whether part of schizophrenia or another disorder, can be paranoid, disorganized/excited, or depressive. In addition, perceptual distortions and motor disturbances can be associated with any type of psychosis. Perceptual distortions include being distressed by hallucinatory voices; hearing voices that accuse, blame, or threaten punishment; seeing visions; reporting hallucinations of touch, taste, or odor; or reporting that familiar things and people seem changed. Motor disturbances are peculiar, rigid postures; overt signs of tension; inappropriate grins or giggles; peculiar repetitive gestures; talking, muttering, or mumbling to oneself; or glancing around as if hearing voices.
In paranoid psychosis, the patient has paranoid projections, hostile belligerence, and grandiose expansiveness. This type of psychosis often occurs in schizophrenia and in many drug-induced psychoses. Paranoid projection includes preoccupation with delusional beliefs; believing that people are talking about oneself; believing one is being persecuted, or being conspired against; and believing people or external forces control one’s actions. A particular type of paranoid delusion may be seen in Parkinson’s disease psychosis; namely, the belief that one’s spouse is being unfaithful or that one’s spouse or loved ones are stealing from them. Hostile belligerence is verbal expression of feelings of hostility; expressing an attitude of disdain; manifesting a hostile, sullen attitude; manifesting irritability and grouchiness; tending to blame others for problems; expressing feelings of resentment; complaining and finding fault; as well as expressing suspicion of people. This, too may be seen especially in schizophrenia and drug-induced psychoses. Grandiose expansiveness is exhibiting an attitude of superiority; hearing voices that praise and extol; believing one has unusual powers or is a well-known personality, or that one has a divine mission, which is often seen in schizophrenia and in manic psychosis
In a disorganized/excited psychosis, there is conceptual disorganization, disorientation, and excitement. Conceptual disorganization can be characterized by giving answers that are irrelevant, or incoherent; drifting off the subject; using neologisms; or repeating certain words or phrases. Any psychotic disorder may exhibit disorganization. Disorientation is not knowing where one is, the season of the year, the calendar year, or one’s own age and is common in psychoses associated with dementias and in drug-induced states. Excitement is expressing feelings without restraint; manifesting speech that is hurried; exhibiting an elevated mood; an attitude of superiority; dramatizing oneself or one’s symptoms; manifesting loud and boisterous speech; exhibiting overactivity or restlessness; and exhibiting excess of speech. Excitement can be especially characteristic of mania or schizophrenia.
Depressive psychosis is characterized by psychomotor retardation, apathy, and anxious self-punishment and blame. Psychomotor retardation and apathy are manifested by slowed speech; indifference to one’s future; fixed facial expression; slowed movements; deficiencies in recent memory; manifesting blocking in speech; apathy toward oneself or one’s problems; slovenly appearance; low or whispered speech; and failure to answer questions. It can be hard to distinguish from negative symptoms of psychosis. Anxious self-punishment and blame is the tendency to blame or condemn oneself; anxiety about specific matters; apprehensiveness regarding vague future events; an attitude of self-deprecation, manifesting depressed mood; expressing feelings of guilt and remorse; preoccupation with suicidal thoughts, unwanted ideas, and specific fears; and feeling unworthy or sinful, seen often in psychotic depression
In summary, the term “psychosis” can be considered to be a set of symptoms in which a person’s mental capacity, affective response, and capacity to recognize reality, communicate, and relate to others is impaired. This brief discussion of clusters of psychotic symptoms does not constitute diagnostic criteria for any psychotic disorder. It is given merely as a description of several types of symptoms that can occur as a part of many different types and causes of psychosis in order to give the reader an overview of the nature of behavioral disturbances associated with the various psychotic illnesses.