ggplot: Extending axis ticks and putting boxes around axis items

This visualization shows the distribution of responses and the prompt text for a collection of Likert (agree/disagree) items. I'd like to make it a little easier for readers to connect the prompt text to the corresponding bar, by putting a box around each prompt and extending the axis tick mark to the appropriate box.

One option to achieve your desired result would be to use ggtext::element_markdown which allows to draw a box around the axis text. Note however, that this requires to use a <br> tag to add line breaks instead of \n.

Using some fake example data:

library(ggplot2)
library(ggtext)

set.seed(123)

dat <- data.frame(
  x = 1:12,
  y = sapply(1:12, \(x) lorem::ipsum_words(12))
)

p <- ggplot(dat) +
  geom_col(
    aes(x, y)
  ) +
  scale_y_discrete(
    labels = \(x) label_wrap_gen()(x) |> gsub("\\n", "<br>", x = _),
    guide = guide_axis(n.dodge = 2)
  ) +
  theme(
    axis.text.y = ggtext::element_markdown(
      box.color = "black",
      linetype = 1,
      padding = unit(2, "pt"),
      linewidth = .25
    )
  )

For the axis ticks you can use a vector to get ticks of different lengths as suggested by @Axeman

p +
  theme(
    axis.ticks.length.y = rel(c(3, 50))
  )

or as a second option use e.g. annotate to fake the axis ticks using a geom_segment which however requires some fiddling to get the lengths right:

p +
  annotate(
    "segment",
    x = 0, xend = -5,
    y = seq(2, 12, 2),
    yend = seq(2, 12, 2),
    linewidth = .5
  ) +
  coord_cartesian(
    clip = "off", xlim = c(0, NA), expand = FALSE
  )