There are three generalized categories in which<unk>  could be acquired by a person. The three categories are head trauma (example: head injuries), traumatic events (example: seeing something devastating to the mind), or physical deficiencies (example: atrophy of the hippocampus). The majority of<unk>  and related memory issues derive from the first two categories as these are more common and the third could be considered a subcategory of the first. *Head trauma is a very broad range as it deals with any kind of injury or active action toward the brain which might cause<unk> . Retrograde and anterograde<unk>  is more often seen from events like this, an exact example of a cause of the two would be electroconvulsive therapy, which would cause both briefly for the receiving patient. *Traumatic events are more subjective. What is traumatic is dependent on what the person finds to be traumatic. Regardless, a traumatic event is an event where something so distressing occurs that the mind chooses to forget rather than deal with the stress. A common example of<unk>  that is caused by traumatic events is dissociative<unk> , which occurs when the person forgets an event that has deeply disturbed them. An example would be a person forgetting a fatal and graphic car accident involving their loved ones. *Physical deficiencies are different from head trauma because physical deficiencies lean more toward passive physical issues. Examples of physical deficiencies include Alzheimer's disease, neurological paraneoplastic syndromes such as anti-NMDA receptor encephalitis, and vitamin B12 deficiency. Among specific causes of<unk>  are the following: *Electroconvulsive therapy in which seizures are electrically induced in patients for therapeutic effect can have acute effects including both retrograde and anterograde<unk> . *Alcohol can both cause blackouts and have deleterious effects on memory formation.
Amnesia
Snatiation
Paranoia
Anhedonia
Allomnesia
Sexual anhedonia
Dyssomnia
Alexithymia