Various mental conditions have been attributed to tabes. Sachs[204] speaks of depressions and neurasthenic conditions with irritability as a special symptom. He has observed paranoid states and manic attacks, sometimes with periods of "transitory dementia" with or without aphasia. He also expresses the opinion that tabetics may develop all of the symptoms of general paresis, although he says that the coexistence of the two diseases is rare. Kraepelin[205] speaks of milder forms of psychoses characterized by uncertainty of memory, fatigability and emotional instability. Many cases exhibit a hopeless, gloomy attitude with depression and fears, or they may be surly, irritable and quarrelsome. Others show a surprisingly good humor. The emotional disturbances often suggest general paresis. Kraepelin, however, describes the characteristic psychosis of locomotor ataxia as assuming a paranoid form and quotes Meyer as reporting paranoic conditions in twenty-six tabetics and depressions of various types in fourteen. He also speaks of hallucinatory excitements resembling alcoholic conditions. These are characterized by a sudden anxiety and restlessness with hallucinations of both hearing and vision. The patients complain of poisoning and sensations of electricity, but are cheerful in mood and well oriented. This condition may last for weeks or months, ending in a sudden recovery, often with relapses. Shorter hallucinatory delirious states resembling crises are also referred to by Kraepelin. More chronic conditions are noted, with hallucinations, persecutory delusions and ideas of grandeur. Delirium tremens, manic-depressive attacks, katatonia or senile psychoses may be associated with tabes.