I mentioned here that I wrote the following entry because I’m a huge nerd, so here it is.
Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, Appendix B: Criteria Sets and Axes Provided for Further Study
Post-Infestation Affective Blunting Syndrome
Features The essential feature of this syndrome is a marked state of lessened facial and postural expressiveness following infestation and hostile control by an extraterrestrial known as a yeerk. Individuals suffering from this syndrome will frequently report a normal range of emotional experiences while also exhibiting blunted or flattened affect. It is associated with a varied degree of distress, ranging from mild to severe. Note that distress and functioning should always be assessed through the form of clinical interviews or self-reports; clinicians’ assessments of emotional stability may not be reliable when examining these individuals. It is also important to note that this syndrome appears to have a high rate of suicidal ideation and a concurrent low rate of suicidal intentions, an area of this syndrome that requires further study.
Associated Features Individuals who exhibit this disorder do not develop it in the absence of yeerk infestation. Yeerk infestation is here defined as the process of hostile control of the individual’s conscious bodily functions by an extraterrestrial entity. This syndrome appears to have similar prevalence rates across ages and genders, although more evidence is needed to determine possible demographic moderating factors. The prognosis for this syndrome is not yet known, although all individuals studied have exhibited consistent patterns of behavior over periods lasting up to three months. Although individuals who present with this condition may not report distress, they may experience threats to normal functioning as a result of their unusual patterns of expression. No information currently exists as to whether it is safe for these individuals to engage in reflex-heavy activities such as driving or operating heavy machinery, and each patient should be evaluated on a case-by-case basis.
Differential Diagnosis In DSM-IV, individuals whose presentation meets these research criteria would be diagnosed as having Post-Traumatic Stress Disorder or Adjustment Disorder, conditional upon the degree of anxiety and intrusive cognition experienced by the individual.
This condition exhibits similar symptoms to Depersonalization Disorder but appears to be more acute in onset and to involve briefer intervals of dissociation. Although certain symptoms mimic the negative symptomatology of Schizophrenia, individuals with this syndrome will typically not demonstrate the marked degree of disorganized behavior that Schizophrenia produces, and do not report experiencing psychosis.
This diagnosis should not be made in the absence of a (self-reported) experience of yeerk infestation and the individual’s belief that the source of the dysfunction arises from the experience of hostile control. It is not clear at this time whether or not voluntary human-controllers experience these symptoms under certain circumstances. More research is also needed to clarify the need for a minimum age of diagnosis.
Prevalence The prevalence of this disorder is not yet known. However, there were approximately 200,000 human-controllers under control of the Yeerk Empire as of March of 2000, and between 40% and 50% of humans surveyed after deinfestation have demonstrated some of the criteria.
Research Criteria
Infestation by one or more yeerks which lasted for a period longer than 12 hours.
Three or more of the following symptoms:
Periods of dissociation, including depersonalization and derealization episodes
Blunted affect or unusual emotional expression which does not match self-reported emotionality
Selective periods of waxy catatonia or other selective lack of movement
Repeated motions of self-stimulation, including at times when socially unacceptable or not entirely within the individual’s conscious control
Intrusive cognitions which specifically relate to themes of loss of personal control and disconnection from one’s body
Delayed or minimal speech production
Blurred or difficult speech production in the absence of aphasia or other speech impairment
Marked impairment to bodily reflexes (flinching, blinking, stimulus orienting, etc.)
All symptoms occurred after such time as the yeerk exited the individual but were absent before the time of infestation according to retroactive self-report.
The symptoms are not directly attributable to brain damage which occurred as a result of forceful ejection of the yeerk or consumption of artificial maple-ginger flavor in the form of oatmeal while infested.
[Disclaimer 1: this would technically be an Appendix entry, not a proper diagnostic entry, so the formatting reflects that. Disclaimer 2: the DSM-IV-TR is available in its entirety online, but anyone who doesn’t have a relevant degree should NOT attempt to diagnose themselves or their friends based on anything they read there. I’m not qualified to use it, you’re (probably) not qualified to use it, and anyone with a Bachelor’s in psych is not qualified to use it. Please please please contact a counselor if you have any concerns rather than going looking for yourself.]