Assessment of Psychosis Part 3: Positive and Negative Symptoms and the CAMPS model
In Part 1, we looked at prevalence rates for psychotic symptoms and psychotic-like symptoms in children and adolescents. In Part 2, we looked at the usual course of psychosis. In this part, we'll review positive, disorganized, and negative psychotic symptoms. Let's start with a review of the DSM-5 criteria for schizophrenia. Certainly, not all individuals who are experiencing psychotic symptoms meet criteria for schizophrenia, and schizophrenia is not the only thought disorder. However, it will make a nice starting point for organizing our discussion around positive and negative psychotic symptoms.
The DSM-5 criteria require: Two or more of the following for at least a one-month (or longer) period of time, and at least one of them must be 1, 2, or 3:
Grossly disorganized or catatonic behavior
Generally, delusions and hallucinations are referred to as positive psychotic symptoms. Disorganized speech and behavior are referred to as positive disorganization symptoms. See the table below for the same information in table form. To meet criteria for schizophrenia, an individual must have at least one positive symptom.
Positive symptoms are called positive because they add something to a person's functioning that was not present before the disorder manifested itself. Positive symptoms are not declines in functioning. They are new perceptions or behaviors that the person did not have before they started experiencing symptoms of psychosis. In general, positive symptoms are exaggerations of normal ideas, perceptions, or behaviors. These thoughts, subjective experiences, or actions show that the person cannot distinguish between what is real and what isn't. The WebMD page does a nice job of laying out types of of positive symptoms, with examples. To summarize:
Hallucinations: Perceiving something no one else does. May be auditory (most common), visual, olfactory, or gustatory.
Delusions: Believing something that would seem strange to most people and that is provable to be wrong. May be persecutory, referential, somatic, erotomanic, religious, or grandiose.
Disorganization: Speech or behavior that seems unclear, unorganized, or purposeless. Speech maybe difficult to follow and not grammatical. Behavior may be inapproriate for the situation and is clearly not how most people act in the situation. Behavior may be seemingly purposeless and repetitive, such as pacing or purposeless repetitive motor movements.
Frank positive symptoms of psychosis are usually relatively obvious, so we won't spend too much time talking about assessing these symptoms. However, what are typically much more difficult to detect are attenuated positive symptoms. Attenuated positive symptoms are symptoms that represent clear disturbances in normal perception or behavior, yet do not quite meet the threshold for a clear positive symptom. These are the symptoms most likely to present during the prodromal period. As summarized in Algon, Yi, Calkins, Kohler & Borgmann-Winter (2012) in their excellent article on evaluating and treatment youth with psychotic symptoms, attenuated positive symptoms can include:
Attenuated Positive Symptoms:
Unusual thought content
Suspicious or persecutory ideas
Perceptual abnormalities (e.g., interpreting everyday sensations in an unusual way)
Attenuated Disorganization Symptoms:
Odd behavior or appearance
Bizarre thinking, such as magical thinking, tangential thinking, or thinking that does not clearly connect cause with effect
Trouble with focus and attention
Poor personal hygiene
As you can see from the list above, determining if something is an attenuated positive symptom can be a bit of a judgment call (e.g., who decides what is "unusual" or "bizarre" thought content?). In later parts in this series, we'll go into more detail about how to evaluate for these attenuated positive symptoms. For now, let's move on to the negative symptoms of psychotic disorders.
Negative symptoms represent declines in or losses of functioning. These symptoms are called negative symptoms because they take away some level of functioning that the person had before the disorder manifested. In general, negative symptoms:
Typically precede positive symptoms in emerging thought disorders by an average of 5 years
Are usually not spontaneously reported by the individual experiencing them
Are often more debilitating overall than the positive symptoms
Are typically more distressing to relatives or friends than to the individual themselves
Correlate more strongly with almost all negative outcomes except hospital re-admissions (which are more associated with positive symptoms)
Are more deteriorative (that is, get worse and cause additional decline over time)
Are more treatment refractory
Improvement in negative symptoms often result in major contributions to overall functioning and quality of life of individuals with active or emerging thought disorders
The table pictured above gives a few examples of negative symptoms. However, there are many more possible negative symptoms. One model I've found really helpful for thinking through all the possible negative symptoms a person may be experiencing comes from Dawn I. Velligan, PhD and Larry D. Alphs, PhD. I don't think they call it this, but I call it the CAMPS model. This acronym is for Communication, Affective, Motivational, Psychomotor, and Social. Let's look at each area in turn:
The negative symptoms that impact communication may limit the quantity and/or the quality of information the person is able to provide in conversation. This is called alogia.
Alogia can include:
Poverty of speech: Using few words or limited elaboration, long latency before replying, or clear thought blocking (person stops mid-sentence, as if their thought was 'blocked' by some external force). Here's a YouTube video showing thought blocking: https://www.youtube.com/watch?v=0u9d96b-Tyc
Poverty of content of speech: Speech that is vague, overly generalized, and "disconnected"
Affect Affective negative symptoms typically limit an individual's emotional expressiveness. The person nonverbal communication, ability to express their affect through nonverbal cues, and their ability to communicate emotions are all blunted. These symptoms are the symptoms most likely to be misdiagnosed as symptoms of depression and/or autism. This can look like:
Anhedonia (loss of pleasure in previously-enjoyed activities)
Blunted affect, monotone, blunted levels of nonverbal communication
Blunted levels of spontaneous movement during social interactions
May not be able to describe emotions
May have trouble demonstrating common emotions if requested
Negative symptoms generally cause a decline in or lack of normal "drives" in the individual. There is usually a decline in not only participation in social and goal-directed behaviors, but a decline in interest in these behaviors. These symptoms require a decline in drive and behavior, so for example, an individual who has never had any sexual interest would not be considered to be having a negative symptom. It is a negative symptom if the drive declines. This can include:
Avolition - this is the specific term for a lack of drive for or ability to engage in goal-directed behavior
Reduced initiation (e.g., of tasks or conversations, may present like total passivity)
Limited interest in participating in self-care or activities (e.g., may do only grudgingly)
Reduced sexual interest
Psychomotor One of the most consistent negative symptoms of psychosis is psychomotor slowing, which is the slowing down of thought, speech, and motor movements.
This can look like:
Limited movement overall
Movements that seem to require more effort than normal
Needing much longer to complete everyday tasks
Needing much more "thinking time" to start a task or answer a question
Gazing blankly in no particular direction
Markedly reduced stamina or energy
Catatonia (this is considered a disorganized negative symptom. Interestingly, catatonia used to be much more common, but now is quite rare.)
Likely secondary to reduced overall motivation, a decline in social motivation is commonly seen as a negative symptom in psychotic disorders. Again, a good developmental history is key, since these symptoms should represent a decline in normal levels of motivation and functioning. If the individual has never shown any social motivation, they would not be considered to have negative symptoms. These symptoms represent a loss of previous interest in social interaction.
This can look like:
Reduced interest in social activities and relationships
Limited attention to social input, possibly to the extent of nonresponsiveness
Limited response to environmental stimuli
Socially "disconnected" or odd
We'll be looking more later into how to assess for these negative symptoms, as well as how to differentiate them from similar symptoms seen in other disorders. For right now, let's make sure we also cover attenuated negative symptoms. These are, as you can guess, symptoms that do not quite meet full threshold for a negative symptom, but which are a clear decline in functioning.
These attenuated negative symptoms can include:
Subtle changes in emotional expressiveness or emotional experience
Lack of ideational richness
Decline in scholastic or adaptive functioning
Impaired tolerance to stress
Now that we have a good review of positive and negative symptoms, let's think back to our case study and see which symptoms Roger might be experiencing. How would you label each of these potential symptoms from his background:
Seemed to just "give up"
Started complaining of difficulty focusing
Started complaining of being confused; adults not sure if he is fully in touch with reality
Stopped showing much interest in things
Often just sat around the house, not doing or saying anything
Started pacing a lot and taking hours-long aimless walks
Seemed to start muttering or laughing to himself
Seemed to think other people were aligned against him
Worried all the time about bugs (presumably when this was not a real concern at home)
Stopped socializing with any friends, even online
Started saying things that didn't make sense
Could only give vague answers to things, and sometimes trailed off mid-sentence
Which ones would you categorize as positive, disorganized, or negative? In the next post in this series, we'll take a look what the research has to say about the neurocognitive symptoms and correlates of psychotic disorders in children and adolescents.