Does writing a letter to someone who died actually help?
Writing to someone who died is a recognized grief practice with reasonable support behind it. It draws on expressive writing research, where writing about difficult experiences is linked to improved wellbeing, and on meaning reconstruction therapy, where letters to the deceased are a standard technique for saying what was left unsaid.
It sounds sentimental until you try it, at which point most people find it is the opposite: concrete, uncomfortable, and unexpectedly relieving.
Why it works
Two mechanisms. James Pennebaker's expressive writing research found that writing about emotionally difficult experiences over a few short sessions was associated with measurable improvements in wellbeing, apparently because putting an experience into language organizes something that was previously formless. Second, Robert Neimeyer's meaning reconstruction approach treats grief as the work of rebuilding a disrupted world of meaning, and uses written correspondence with the deceased as a deliberate therapeutic technique. The unsaid, given a form, stops circling.
How to start
Fifteen minutes, one sitting, no audience, no editing. Handwriting or typing both work. Begin with the plainest possible opener: "There are things I never said." Then pick one of these and go: what you wish you had told them, what you are angry about, what you are grateful for, an apology you never delivered, or simply an update on your life since they died.
Write to them, in your own voice, in the second person. That direction matters. You are speaking to them, not manufacturing a reply.
The one thing to avoid
Do not write their reply. This is where a helpful practice quietly becomes a harmful one. Continuing bonds research distinguishes between an inner relationship carried in memory and meaning, which is associated with adjustment, and relating to the deceased as still concretely present and responsive, which is associated with poorer outcomes. Writing TO someone is remembrance. Composing their answer, or having software compose it, converts a memory into a simulation, which is precisely why Still Here refuses to speak as the dead.
What to do with the letter afterward
Whatever you like. Keep it in a drawer, read it aloud at the grave, burn it, bury it, or add to it on anniversaries (a good use of a milestone day). Some people write one letter a year and find the accumulating stack becomes its own record of the relationship continuing to change.
If it makes things worse
For a minority, writing opens more than it settles, particularly after traumatic or violent deaths where intrusive images may intensify. If that is you, stop, and do this work with a grief-trained therapist rather than alone. That is not failure; certain material genuinely needs a person in the room.
See also: Pennebaker & Beall (1986) Journal of Abnormal Psychology, and subsequent expressive writing research; Neimeyer (2001, 2019) on meaning reconstruction and grief therapy techniques; Field, Gao & Paderna (2005) Death Studies, on continuing bonds.