31st January 2024

Psychiatric differentials

Firstly, there are other psychiatric disorders that can present physical health impacts from reduced eating, but the psychological factors driving disordered eating are different. These would include:

• Depressive disorders, where motivation and anhedonia lead to self-neglect and reduced eating. This often requires quite a severe depressive episode and delayed presentation to impact on physical health.
• Obsessive-compulsive disorder, where obsessive thoughts and corresponding compulsion lead to reduced intake, e.g., needing to complete a ritual means there is no time to eat in the person’s schedule.
• Psychotic disorders (e.g., schizophrenia), where delusions or gustatory (taste) hallucinations mean a person believes food is poisoned or inedible items are food. Rarely a person might have a delusional belief of being overweight as part of their psychotic disorder. This is not usually the presenting symptom. 
• Attention Deficit Hyperactivity Disorder, either due to appetite reduction secondary to amphetamines, or where hyperactivity and distractibility lead to unintentional excessive exercise and inability to finish a meal.
• Personality disorders, where food refusal, excessive exercise or purging is a form of self-harm