Major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SCZ) are psychiatric disorders that significantly impact an individual's ability to function effectively within society. MDD is characterized by persistent low mood, leading to symptoms such as anhedonia, feelings of worthlessness, and cognitive impairments. BD, another mood disorder, is typified by recurrent episodes of depression and mania or hypomania. The disorder is associated with increased risk of suicide, comorbid psychiatric conditions, and impaired functioning across various domains. SCZ, a severe psychiatric disorder primarily characterized by hallucinations, delusions, and disorganized thinking, affects approximately 1% of the global population. The cognitive, social, and occupational impairments associated with SCZ impose a substantial burden on affected individuals and their families. Even though it sounds like three completely different mental disorders, because of the high degree of matching of symptoms, we firmly believe that there is a relationship between these mental disorders. Protein folding is crucial for proper protein function, and misfolding can lead to neurodegenerative disorders. Through recent research findings, we found that the changes in A plaques and tau tangles appeared in the typical psychiatric diseases mentioned above. This paper explored the impact of protein misfolding, changes in A plaques, and tau tangles on neurological disorders, with a focus on depression, bipolar disorder, and schizophrenia, also examines the role of molecular chaperones in preventing misfolding and the impact of protein misfolding.