294.9 is a diagnostic code number from the Diagnostic and Statistical Manual; the manual which lists all psychiatric disorders.
294.2 is Cognitive Disorder NOS. NOS means Not Otherwise Specified.
This category is for disorders that are characterized by cognitive dysfunction presumed to be due to the direct physiological effect of a general medical condition that do not meet criteria for any of the specific deliriums, dementias, or amnestic disorders listed in (that particular) section and that are not better classified as Delirium Not Otherwise Specified, Dementia Not Otherwise Specified, or Amnestic Disorder Not Otherwise Specified. For cognitive dysfunction due to a specific or unknown substance, the specific Substance-Related Disorder Not Otherwise Specified category should be used.
1. Mild neurocognitive disorder: impairment in cognitive functioning as evidenced by neuropsychological testing or quantified clinical assessment, accompanied by objective evidence of a systemic general medical condition or central nervous system dysfunction.
2. Postconcussional disorder following a head trauma, impairment in memory or attention with associated symptoms.
Both terms (Psychiatric and Neuropsychological) refer to the brain. The terms are somewhat interchangeable; we say that someone will take a neuropsychological test (a written/oral test) or have a psychiatric evaluation. They both refer to inquiries related to the brain.
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