Final answer:
Psychologists ethically end treatment when the client is no longer benefiting from the therapy, not necessarily when they are 'cured,' cannot pay, or cannot form a therapeutic alliance. Decisions are client-centered and grounded in professional and ethical considerations within the field of clinical psychology.
Step-by-step explanation:
Psychologists are expected to end treatment when the client is no longer benefiting from the therapy. This ethical decision is based on the professional judgment of the psychologist. If a client is not making progress or has achieved as much change as possible, continuing treatment may not be helpful and could even be counterproductive. Therapists are guided by various therapy approaches, such as cognitive-behavioral therapy, and by principled frameworks that emphasize the importance of benefitting the client.
However, other factors, such as being 'cured' of all psychological issues, a client's ability to pay, or the inability to form a therapeutic alliance, may affect the continuity of service but are not definitive grounds to ethically mandate the termination of therapy. Decisions around ending psychological treatment are complex and take into account the individual client's needs, therapeutic goals, and the professional and ethical guidelines governing the practice of clinical psychology.