What diagnosis is likely for someone who alternates between motionlessness and hyperactivity?

The diagnosis that aligns with alternating periods of motionlessness and hyperactivity is catatonic schizophrenia. This subtype of schizophrenia is characterized by significant motor disturbances. Individuals may exhibit catatonia, where they seem to be in a stupor, remaining still and unresponsive for extended periods, followed by episodes of excessive motor activity or agitation. The cyclical nature of these behaviors is a defining feature of the disorder.

In contrast, other diagnoses listed involve different symptomatology. Major depressive disorder typically presents with a persistent low mood and a lack of energy rather than alternating states of high and low energy. Borderline personality disorder can involve emotional instability but does not specifically manifest as extreme motor fluctuations. Obsessive-compulsive disorder primarily consists of intrusive thoughts and repetitive behaviors rather than the changes in physical activity level exhibited in catatonic schizophrenia. Hence, the presence of alternating motionlessness and hyperactivity distinctly supports the diagnosis of catatonic schizophrenia.