How do you tell ADHD-related forgetfulness from early depression symptoms?

This is a really thoughtful question, because the two can look similar on the surface, but clinically they feel different underneath. ADHD related forgetfulness is usually about access, not loss. The information is there, but it is inconsistently retrievable. People forget appointments, tasks, or where they put things, especially when distracted or overwhelmed. It tends to be variable. Some days are better, some worse. When something is interesting, urgent, or emotionally engaging, memory often improves noticeably. Depression related cognitive changes are more about slowing and depletion. Memory, concentration, and processing feel globally dulled. People describe brain fog, difficulty thinking, slowed recall, and trouble holding thoughts even when they care about the task. It is less about distraction and more about everything feeling effortful. Emotionally, ADHD forgetfulness often comes with frustration and self blame but preserved drive. People still want to do things, they just cannot organize or execute consistently. With depression, motivation itself is reduced. Forgetfulness is often paired with low mood, low energy, anhedonia, and a sense of heaviness or numbness. Timeline matters too. ADHD patterns are lifelong, even if they fluctuate. Depression related cognitive changes usually represent a shift from baseline. Someone might say I used to be sharp and now my brain feels slow. That change is important. In real life, these often overlap. Untreated ADHD can lead to depression, and depression can worsen executive function. So it is not always either or. Clinically, we look at history, variability, mood symptoms, energy, sleep, and what improves focus. Treating one often helps clarify the other. If you are feeling low and forgetful, that deserves care on both fronts. It is not a failure of willpower. It is your brain asking for support.