What condition is described by profound alterations in thinking and perception as per the DSM IV?

The condition characterized by profound alterations in thinking and perception, as described in the DSM IV, is schizophrenia. This mental disorder is marked by symptoms such as delusions, hallucinations, disorganized thinking, and significant disruptions in cognition and emotional responsiveness. Individuals with schizophrenia may experience a distorted sense of reality, which can severely impact their ability to function in daily life.

The symptoms are not just transient; they significantly affect how individuals perceive the world around them and can lead to difficulties in distinguishing between what is real and what is not. This is a core aspect of the disorder that distinguishes it from other conditions listed. While depression, generalized anxiety disorder, and bipolar disorder can involve changes in mood and thoughts, they do not typically encompass the profound distortions in reality that define schizophrenia.