Frostigs and Tom Spies—according to Cleary and Cleary—described more specific psychological symptoms of pellagra as:

Psychosensory disturbances (impressions as being painful, annoying bright lights, odors intolerance causing nausea and vomiting, dizziness after sudden movements),
Psychomotor disturbances (restlessness, tense and a desire to quarrel, increased preparedness for motor action), as well as
Emotional disturbancesIndependently of clinical symptoms, blood level of tryptophan or urinary metabolites such as 2-pyridone/N-methylniacinamide ratio <2 or NAD/NADP ratio in red blood cells can diagnose pellagra. The diagnosis is confirmed by rapid improvements in symptoms after doses of niacin (250–500 mg/day) or niacin enriched food. Pathophysiology
Pellagra can develop according to several mechanisms, classically as a result of niacin (vitamin B3) deficiency, which results in decreased nicotinamide adenine dinucleotide (NAD). Since NAD and its phosphorylated NADP form are cofactors required in many body processes, the pathological impact of pellagra is broad and results in death if not treated. The first mechanism is simple dietary lack of niacin. Second, it may result from deficiency of tryptophan, an essential amino acid found in meat, poultry, fish, eggs, and peanuts that the body uses to make niacin. Third, it may be caused by excess leucine, as it inhibits quinolinate phosphoribosyl transferase (QPRT) and inhibits the formation of niacin or nicotinic acid to nicotinamide mononucleotide (NMN) causing pellagra like symptoms to occur.Some conditions can prevent the absorption of dietary niacin or tryptophan and lead to pellagra. Inflammation of the jejunum or ileum can prevent nutrient absorption, leading to pellagra, and this can in turn be caused by Crohns disease.
Drug Information Portal. U.S. National Library of Medicine. "Umbralisib". NCI Drug Dictionary. National Cancer Institute.