A 32-year-old man was brought to the psychiatric hospital by his older sister due to unusual thoughts and actions, diminished enjoyment, and peculiar movements. The patient did not have any history of symptoms before the age of 27 and was considred fairly normal. He had never been married and had no children, often residing with their older siblings. He denied any substance use apart from being a smoker for the past 8 years. During the evaluation, the patient disclosed experiencing prolonged periods of low mood, accompanied by reduced pleasure, sleep disturbances, and fatigue. He became socially withdrawn and expressed a persistent feeling of sadness, finding no joy in any activities.
Additionally, he held baseless beliefs that someone had insulted him and was plotting to harm him. He also developed an irrational fear of water sounds, an overall absence of pleasure, negative thought patterns, and expressed difficulties in placing trust in others. Subsequently, his symptoms worsened, leading to restlessness, agitation, racing thoughts, and a conviction that an external force was manipulating his mind. He engaged in repetitive and ritualistic behaviors, such as following a strict walking pattern, and felt an increasing lack of control over these actions. Realizing the impact of
"unfamiliar thoughts" and a perceived "shadow presence" on his mental state, he was admitted to the hospital. whats his diagnosis