Answer:
Korsakoff's syndrome.
Step-by-step explanation:
Korsakoff's syndrome may be defined as a type of amnestic disorder and caused by the deficiency of thiamine. The prolonged ingestion of alcohol is the main cause of this Korsakoff's syndrome.
A participant was long-term alcoholic and has distorted memory. These all are the symptoms of Korsakoff's syndrome. The participant is most probably suffering from the Korsakoff's syndrome.
Thus, the answer is Korsakoff's syndrome.