Which of the following has to be present for diagnosis of manic-depressive psychosis?
**Core Concept**
Manic-depressive psychosis, now more commonly referred to as bipolar disorder, is a mood disorder characterized by recurrent episodes of mania or hypomania, often alternating with depressive episodes. The diagnosis of bipolar disorder is crucial for appropriate management and treatment.
**Why the Correct Answer is Right**
The correct answer is **C. Cyclical pattern of illness**. For a diagnosis of manic-depressive psychosis, there must be a clear cyclical pattern of illness, with distinct episodes of mania or hypomania and depression. This cyclical pattern is essential for differentiating bipolar disorder from other mood disorders, such as unipolar depression. The cyclical pattern of illness is often described as a "mood swing" between the two extremes, which is a hallmark of bipolar disorder.
**Why Each Wrong Option is Incorrect**
**Option A:** **A. At least one episode of mania** is not sufficient for diagnosis, as the presence of mania alone does not rule out other conditions, such as schizophrenia or substance-induced psychosis. Furthermore, not all individuals with bipolar disorder will experience a full-blown manic episode.
**Option B:** **B. Depressive episodes only** is not indicative of manic-depressive psychosis, as the diagnosis requires a distinct episode of mania or hypomania, in addition to depressive episodes.
**Option D:** **D. No clear pattern of illness** would make it challenging to diagnose bipolar disorder, as the cyclical pattern of illness is a key characteristic of the condition.
**Clinical Pearl / High-Yield Fact**
The cyclical pattern of illness in bipolar disorder can be remembered using the mnemonic "MOOD," which stands for Mania, Obsessive thinking, Odd behavior, and Depression. This mnemonic helps clinicians to recognize the characteristic symptoms of bipolar disorder.
**Correct Answer: C. Cyclical pattern of illness**