Other Diagnoses that Can Masquerade as Psychotic Illnesses
- Delirium - Patients often have paranoia, visual hallucinations.
- Paranoid Personality Disorder and Schizotypal Personality Disorder can dance very near the edge of psychosis.
- Obsessive Compulsive Disorder - At times obsessions can be difficult to discern from psychosis.
Diagnostic Considerations
Key Questions
- Are psychotic symptoms only present when mood symptoms are present?
- Does the patient have a medical condition that can cause psychosis?
- Is the patient using drugs/ETOH? If yes, need to have symptoms present after at least a month of sobriety; otherwise, it is attributed to substances.
- Does the patient have prominent negative symptoms?
- Is the patient delusional or psychotic?
- What is the nature of the psychotic symptoms? Are they mood congruent (depressive themes associated with the psychosis) or incongruent?
Differential Diagnoses for Psychotic Disorders
- Mood Disorders with Psychotic Features
- Schizophrenia and Schizophreniform Disorder
- Substance-Induced Psychotic Disorder
- Delusional Disorder
- Psychotic Disorder due to General Medical Condition
- Shared Psychotic Disorder (Folie à Deux)
- Psychotic Disorder NOS
Hallucinations
- Hallucinations are defined as false sensory perceptions not associated with real external stimuli.
Delusions
- Delusions are defined as a false belief based on incorrect inference about external reality that is firmly held despite what most everyone else believes and despite what constitutes incontrovertible and obvious proof of evidence to the contrary.
- Always keep in mind cultural norms.
Mood Incongruent
- Mood incongruent themes include delusions of control, persecution, thought broadcasting, and thought insertion.
Mood Congruent
- Delusions or hallucinations consistent with themes of a depressed mood such as personal inadequacy, guilt, disease, death, and deserved punishment. For manic mood themes of worth, power, knowledge, and special relationship to a deity.
Diagnosis Guidelines
- The diagnosis cannot be made if the symptoms occurred before the substance or medication was ingested, or are more severe than could be reasonably caused by the amount of substance involved.
- If the disorder persists for more than a month after the withdrawal of the substance, the diagnosis is less likely with the exception of methamphetamines.