diff --git a/app/components/admin/search_component.html.erb b/app/components/admin/search_component.html.erb
index 0286dcb48..4658f2971 100644
--- a/app/components/admin/search_component.html.erb
+++ b/app/components/admin/search_component.html.erb
@@ -1,4 +1,5 @@
 <%= form_tag(url, options) do |f| %>
+  <%= hidden_current_filter_tag %>
   <%= text_field_tag :search, search_terms.to_s, placeholder: label, "aria-label": label %>
   <%= content %>
   <%= submit_tag t("admin.shared.search.search") %>
diff --git a/app/components/admin/search_component.rb b/app/components/admin/search_component.rb
index e7c4a3e45..6a75b029a 100644
--- a/app/components/admin/search_component.rb
+++ b/app/components/admin/search_component.rb
@@ -20,4 +20,14 @@ class Admin::SearchComponent < ApplicationComponent
     def options
       { method: :get, role: "search" }.merge(form_options)
     end
+
+    def hidden_current_filter_tag
+      hidden_field_tag(:filter, current_filter) if current_filter
+    end
+
+    def current_filter
+      if helpers.respond_to?(:current_filter)
+        helpers.current_filter
+      end
+    end
 end
diff --git a/app/components/sdg_management/relations/index_component.html.erb b/app/components/sdg_management/relations/index_component.html.erb
index 4dfd0cc5a..57127a51f 100644
--- a/app/components/sdg_management/relations/index_component.html.erb
+++ b/app/components/sdg_management/relations/index_component.html.erb
@@ -1,6 +1,6 @@
 <%= header %>
 
-<%= render SDGManagement::Relations::SearchComponent.new(label: search_label, current_filter: current_filter) %>
+<%= render SDGManagement::Relations::SearchComponent.new(label: search_label) %>
 <%= render "shared/filter_subnav", i18n_namespace: "sdg_management.relations.index" %>
 
 <table>
diff --git a/app/components/sdg_management/relations/index_component.rb b/app/components/sdg_management/relations/index_component.rb
index 0db934e13..55fdde345 100644
--- a/app/components/sdg_management/relations/index_component.rb
+++ b/app/components/sdg_management/relations/index_component.rb
@@ -1,7 +1,5 @@
 class SDGManagement::Relations::IndexComponent < ApplicationComponent
   include Header
-  delegate :valid_filters, :current_filter, to: :helpers
-
   attr_reader :records
 
   def initialize(records)
diff --git a/app/components/sdg_management/relations/search_component.html.erb b/app/components/sdg_management/relations/search_component.html.erb
index d77f21c8f..31282e747 100644
--- a/app/components/sdg_management/relations/search_component.html.erb
+++ b/app/components/sdg_management/relations/search_component.html.erb
@@ -5,5 +5,4 @@
   <%= component.select_tag :target_code, target_options,
                            include_blank: target_blank_option,
                            "aria-label": target_label %>
-  <%= component.hidden_field_tag :filter, current_filter %>
 <% end %>
diff --git a/app/components/sdg_management/relations/search_component.rb b/app/components/sdg_management/relations/search_component.rb
index fdbe9c833..c48504424 100644
--- a/app/components/sdg_management/relations/search_component.rb
+++ b/app/components/sdg_management/relations/search_component.rb
@@ -1,10 +1,9 @@
 class SDGManagement::Relations::SearchComponent < ApplicationComponent
   include SDG::OptionsForSelect
-  attr_reader :label, :current_filter
+  attr_reader :label
 
-  def initialize(label:, current_filter: nil)
+  def initialize(label:)
     @label = label
-    @current_filter = current_filter
   end
 
   private
diff --git a/app/controllers/admin/hidden_budget_investments_controller.rb b/app/controllers/admin/hidden_budget_investments_controller.rb
index 6b977cdd3..dc095bd1e 100644
--- a/app/controllers/admin/hidden_budget_investments_controller.rb
+++ b/app/controllers/admin/hidden_budget_investments_controller.rb
@@ -1,16 +1,13 @@
 class Admin::HiddenBudgetInvestmentsController < Admin::BaseController
   include FeatureFlags
-
-  has_filters %w[all with_confirmed_hide without_confirmed_hide], only: :index
+  include Admin::HiddenContent
 
   feature_flag :budgets
 
   before_action :load_investment, only: [:confirm_hide, :restore]
 
   def index
-    @investments = Budget::Investment.only_hidden.send(@current_filter)
-                                                 .order(hidden_at: :desc)
-                                                 .page(params[:page])
+    @investments = hidden_content(Budget::Investment.all)
   end
 
   def confirm_hide
diff --git a/app/controllers/admin/hidden_comments_controller.rb b/app/controllers/admin/hidden_comments_controller.rb
index fc778a1a6..50270eb92 100644
--- a/app/controllers/admin/hidden_comments_controller.rb
+++ b/app/controllers/admin/hidden_comments_controller.rb
@@ -1,11 +1,10 @@
 class Admin::HiddenCommentsController < Admin::BaseController
-  has_filters %w[without_confirmed_hide all with_confirmed_hide]
+  include Admin::HiddenContent
 
   before_action :load_comment, only: [:confirm_hide, :restore]
 
   def index
-    @comments = Comment.not_valuations.only_hidden.with_visible_author
-                       .send(@current_filter).order(hidden_at: :desc).page(params[:page])
+    @comments = hidden_content(Comment.not_valuations).with_visible_author
   end
 
   def confirm_hide
diff --git a/app/controllers/admin/hidden_debates_controller.rb b/app/controllers/admin/hidden_debates_controller.rb
index b5a4ea502..7c267c746 100644
--- a/app/controllers/admin/hidden_debates_controller.rb
+++ b/app/controllers/admin/hidden_debates_controller.rb
@@ -1,14 +1,13 @@
 class Admin::HiddenDebatesController < Admin::BaseController
   include FeatureFlags
+  include Admin::HiddenContent
 
   feature_flag :debates
 
-  has_filters %w[without_confirmed_hide all with_confirmed_hide], only: :index
-
   before_action :load_debate, only: [:confirm_hide, :restore]
 
   def index
-    @debates = Debate.only_hidden.send(@current_filter).order(hidden_at: :desc).page(params[:page])
+    @debates = hidden_content(Debate.all)
   end
 
   def confirm_hide
diff --git a/app/controllers/admin/hidden_proposal_notifications_controller.rb b/app/controllers/admin/hidden_proposal_notifications_controller.rb
index 365471dd6..27f09b6b1 100644
--- a/app/controllers/admin/hidden_proposal_notifications_controller.rb
+++ b/app/controllers/admin/hidden_proposal_notifications_controller.rb
@@ -1,13 +1,10 @@
 class Admin::HiddenProposalNotificationsController < Admin::BaseController
-  has_filters %w[without_confirmed_hide all with_confirmed_hide], only: :index
+  include Admin::HiddenContent
 
   before_action :load_proposal, only: [:confirm_hide, :restore]
 
   def index
-    @proposal_notifications = ProposalNotification.only_hidden
-                                                  .send(@current_filter)
-                                                  .order(hidden_at: :desc)
-                                                  .page(params[:page])
+    @proposal_notifications = hidden_content(ProposalNotification.all)
   end
 
   def confirm_hide
diff --git a/app/controllers/admin/hidden_proposals_controller.rb b/app/controllers/admin/hidden_proposals_controller.rb
index 8ee137140..86be183a7 100644
--- a/app/controllers/admin/hidden_proposals_controller.rb
+++ b/app/controllers/admin/hidden_proposals_controller.rb
@@ -1,15 +1,13 @@
 class Admin::HiddenProposalsController < Admin::BaseController
   include FeatureFlags
-
-  has_filters %w[without_confirmed_hide all with_confirmed_hide], only: :index
+  include Admin::HiddenContent
 
   feature_flag :proposals
 
   before_action :load_proposal, only: [:confirm_hide, :restore]
 
   def index
-    @proposals = Proposal.only_hidden.send(@current_filter).order(hidden_at: :desc)
-                         .page(params[:page])
+    @proposals = hidden_content(Proposal.all)
   end
 
   def confirm_hide
diff --git a/app/controllers/admin/hidden_users_controller.rb b/app/controllers/admin/hidden_users_controller.rb
index 86801fcda..536d8d725 100644
--- a/app/controllers/admin/hidden_users_controller.rb
+++ b/app/controllers/admin/hidden_users_controller.rb
@@ -1,10 +1,10 @@
 class Admin::HiddenUsersController < Admin::BaseController
-  has_filters %w[without_confirmed_hide all with_confirmed_hide], only: :index
+  include Admin::HiddenContent
 
   before_action :load_user, only: [:confirm_hide, :restore]
 
   def index
-    @users = User.only_hidden.send(@current_filter).order(hidden_at: :desc).page(params[:page])
+    @users = hidden_content(User.all)
   end
 
   def show
diff --git a/app/controllers/concerns/admin/hidden_content.rb b/app/controllers/concerns/admin/hidden_content.rb
new file mode 100644
index 000000000..7269539a8
--- /dev/null
+++ b/app/controllers/concerns/admin/hidden_content.rb
@@ -0,0 +1,15 @@
+module Admin::HiddenContent
+  extend ActiveSupport::Concern
+  include Search
+
+  included do
+    has_filters %w[without_confirmed_hide all with_confirmed_hide], only: :index
+  end
+
+  def hidden_content(relation)
+    records = relation.only_hidden
+    records = records.search(@search_terms) if @search_terms.present?
+
+    records.send(@current_filter).order(hidden_at: :desc).page(params[:page])
+  end
+end
diff --git a/app/models/comment.rb b/app/models/comment.rb
index 8e7c886a5..e1a348bfa 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -3,6 +3,7 @@ class Comment < ApplicationRecord
   include HasPublicAuthor
   include Graphqlable
   include Notifiable
+  include Searchable
 
   COMMENTABLE_TYPES = %w[Debate Proposal Budget::Investment Poll Topic
                         Legislation::Question Legislation::Annotation
@@ -131,6 +132,17 @@ class Comment < ApplicationRecord
     cached_votes_up - cached_votes_down
   end
 
+  def searchable_values
+    {
+      body               => "A",
+      commentable&.title => "B"
+    }
+  end
+
+  def self.search(terms)
+    pg_search(terms)
+  end
+
   private
 
     def validate_body_length
diff --git a/app/models/concerns/search_cache.rb b/app/models/concerns/search_cache.rb
index ad25b07de..478f9a0e1 100644
--- a/app/models/concerns/search_cache.rb
+++ b/app/models/concerns/search_cache.rb
@@ -6,7 +6,7 @@ module SearchCache
   end
 
   def calculate_tsvector
-    self.class.where(id: id).update_all("tsv = (#{searchable_values_sql})")
+    self.class.with_hidden.where(id: id).update_all("tsv = (#{searchable_values_sql})")
   end
 
   private
diff --git a/app/models/proposal_notification.rb b/app/models/proposal_notification.rb
index a49dfe9a2..8e24bca40 100644
--- a/app/models/proposal_notification.rb
+++ b/app/models/proposal_notification.rb
@@ -1,6 +1,7 @@
 class ProposalNotification < ApplicationRecord
   include Graphqlable
   include Notifiable
+  include Searchable
 
   belongs_to :author, class_name: "User"
   belongs_to :proposal
@@ -55,6 +56,17 @@ class ProposalNotification < ApplicationRecord
     update(moderated: false)
   end
 
+  def searchable_values
+    {
+      title => "A",
+      body  => "B"
+    }
+  end
+
+  def self.search(terms)
+    pg_search(terms)
+  end
+
   private
 
     def set_author
diff --git a/app/views/admin/hidden_budget_investments/index.html.erb b/app/views/admin/hidden_budget_investments/index.html.erb
index 0fa2879ac..34c3201ea 100644
--- a/app/views/admin/hidden_budget_investments/index.html.erb
+++ b/app/views/admin/hidden_budget_investments/index.html.erb
@@ -1,4 +1,5 @@
 <h2><%= t("admin.hidden_budget_investments.index.title") %></h2>
+<%= render Admin::SearchComponent.new(label: t("admin.shared.search.label.budget_investments")) %>
 <p><%= t("admin.shared.moderated_content") %></p>
 
 <%= render "shared/filter_subnav", i18n_namespace: "admin.hidden_budget_investments.index" %>
diff --git a/app/views/admin/hidden_comments/index.html.erb b/app/views/admin/hidden_comments/index.html.erb
index dbf9c84a1..1cc84b84b 100644
--- a/app/views/admin/hidden_comments/index.html.erb
+++ b/app/views/admin/hidden_comments/index.html.erb
@@ -1,4 +1,5 @@
 <h2><%= t("admin.hidden_comments.index.title") %></h2>
+<%= render Admin::SearchComponent.new(label: t("admin.shared.search.label.comments")) %>
 <p><%= t("admin.shared.moderated_content") %></p>
 
 <%= render "shared/filter_subnav", i18n_namespace: "admin.hidden_comments.index" %>
diff --git a/app/views/admin/hidden_debates/index.html.erb b/app/views/admin/hidden_debates/index.html.erb
index 3074ab646..8c50d90aa 100644
--- a/app/views/admin/hidden_debates/index.html.erb
+++ b/app/views/admin/hidden_debates/index.html.erb
@@ -1,4 +1,5 @@
 <h2><%= t("admin.hidden_debates.index.title") %></h2>
+<%= render Admin::SearchComponent.new(label: t("admin.shared.search.label.debates")) %>
 <p><%= t("admin.shared.moderated_content") %></p>
 
 <%= render "shared/filter_subnav", i18n_namespace: "admin.hidden_debates.index" %>
diff --git a/app/views/admin/hidden_proposal_notifications/index.html.erb b/app/views/admin/hidden_proposal_notifications/index.html.erb
index 31aafc141..227a38215 100644
--- a/app/views/admin/hidden_proposal_notifications/index.html.erb
+++ b/app/views/admin/hidden_proposal_notifications/index.html.erb
@@ -1,4 +1,5 @@
 <h2><%= t("admin.hidden_proposal_notifications.index.title") %></h2>
+<%= render Admin::SearchComponent.new(label: t("admin.shared.search.label.proposal_notifications")) %>
 <p><%= t("admin.shared.moderated_content") %></p>
 
 <%= render "shared/filter_subnav", i18n_namespace: "admin.hidden_proposal_notifications.index" %>
diff --git a/app/views/admin/hidden_proposals/index.html.erb b/app/views/admin/hidden_proposals/index.html.erb
index c28f0f5d4..83a36e329 100644
--- a/app/views/admin/hidden_proposals/index.html.erb
+++ b/app/views/admin/hidden_proposals/index.html.erb
@@ -1,4 +1,5 @@
 <h2><%= t("admin.hidden_proposals.index.title") %></h2>
+<%= render Admin::SearchComponent.new(label: t("admin.shared.search.label.proposals")) %>
 <p><%= t("admin.shared.moderated_content") %></p>
 
 <%= render "shared/filter_subnav", i18n_namespace: "admin.hidden_proposals.index" %>
diff --git a/app/views/admin/hidden_users/index.html.erb b/app/views/admin/hidden_users/index.html.erb
index c4addaeda..9f31bdd7e 100644
--- a/app/views/admin/hidden_users/index.html.erb
+++ b/app/views/admin/hidden_users/index.html.erb
@@ -1,4 +1,5 @@
 <h2><%= t("admin.hidden_users.index.title") %></h2>
+<%= render "admin/shared/user_search", url: admin_hidden_users_path %>
 <p><%= t("admin.shared.moderated_content") %></p>
 
 <%= render "shared/filter_subnav", i18n_namespace: "admin.hidden_users.index" %>
diff --git a/config/locales/en/admin.yml b/config/locales/en/admin.yml
index c6bedf583..f615458c3 100644
--- a/config/locales/en/admin.yml
+++ b/config/locales/en/admin.yml
@@ -1346,6 +1346,7 @@ en:
         label:
           booths: "Search booth by name or location"
           budget_investments: "Search investments by title, description or heading"
+          comments: "Search comments"
           debates: "Search debates by title or description"
           legislation_processes: "Search processes by title or description"
           legislation_proposals: "Search proposals by title or description"
@@ -1355,6 +1356,7 @@ en:
           poll_questions: "Search poll questions"
           polls: "Search polls by name or description"
           proposals: "Search proposals by title, code, description or question"
+          proposal_notifications: "Search notifications by title or description"
           users: "Search user by name or email"
         search: "Search"
       search_results: "Search results"
diff --git a/config/locales/es/admin.yml b/config/locales/es/admin.yml
index 42d446409..aa861ab09 100644
--- a/config/locales/es/admin.yml
+++ b/config/locales/es/admin.yml
@@ -1345,6 +1345,7 @@ es:
         label:
           booths: "Buscar urna por nombre"
           budget_investments: "Buscar proyectos por título, descripción o partida"
+          comments: "Buscar comentarios"
           debates: "Buscar debates por título o descripción"
           legislation_processes: "Buscar procesos por título o descripción"
           legislation_proposals: "Buscar propuestas por título o descripción"
@@ -1354,6 +1355,7 @@ es:
           poll_questions: "Buscar preguntas"
           polls: "Buscar votaciones por nombre o descripción"
           proposals: "Buscar propuestas por título, código, descripción o pregunta"
+          proposal_notifications: "Buscar notificaciones por título o descripción"
           users: "Buscar usuario por nombre o email"
         search: "Buscar"
       search_results: "Resultados de la búsqueda"
diff --git a/db/migrate/20190307113726_add_tsvector_to_comments_and_proposal_notifications.rb b/db/migrate/20190307113726_add_tsvector_to_comments_and_proposal_notifications.rb
new file mode 100644
index 000000000..16f7389f8
--- /dev/null
+++ b/db/migrate/20190307113726_add_tsvector_to_comments_and_proposal_notifications.rb
@@ -0,0 +1,9 @@
+class AddTsvectorToCommentsAndProposalNotifications < ActiveRecord::Migration[5.2]
+  def change
+    add_column :comments, :tsv, :tsvector
+    add_index :comments, :tsv, using: "gin"
+
+    add_column :proposal_notifications, :tsv, :tsvector
+    add_index :proposal_notifications, :tsv, using: "gin"
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 9b9355562..8d87806d6 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -448,6 +448,7 @@ ActiveRecord::Schema.define(version: 2021_11_03_112944) do
     t.string "ancestry"
     t.integer "confidence_score", default: 0, null: false
     t.boolean "valuation", default: false
+    t.tsvector "tsv"
     t.index ["ancestry"], name: "index_comments_on_ancestry"
     t.index ["cached_votes_down"], name: "index_comments_on_cached_votes_down"
     t.index ["cached_votes_total"], name: "index_comments_on_cached_votes_total"
@@ -455,6 +456,7 @@ ActiveRecord::Schema.define(version: 2021_11_03_112944) do
     t.index ["commentable_id", "commentable_type"], name: "index_comments_on_commentable_id_and_commentable_type"
     t.index ["confidence_score"], name: "index_comments_on_confidence_score"
     t.index ["hidden_at"], name: "index_comments_on_hidden_at"
+    t.index ["tsv"], name: "index_comments_on_tsv", using: :gin
     t.index ["user_id"], name: "index_comments_on_user_id"
     t.index ["valuation"], name: "index_comments_on_valuation"
   end
@@ -1268,6 +1270,8 @@ ActiveRecord::Schema.define(version: 2021_11_03_112944) do
     t.datetime "hidden_at"
     t.datetime "ignored_at"
     t.datetime "confirmed_hide_at"
+    t.tsvector "tsv"
+    t.index ["tsv"], name: "index_proposal_notifications_on_tsv", using: :gin
   end
 
   create_table "proposal_translations", id: :serial, force: :cascade do |t|
diff --git a/lib/tasks/consul.rake b/lib/tasks/consul.rake
index 6bd19134b..f1074d23e 100644
--- a/lib/tasks/consul.rake
+++ b/lib/tasks/consul.rake
@@ -2,10 +2,15 @@ namespace :consul do
   desc "Runs tasks needed to upgrade to the latest version"
   task execute_release_tasks: ["settings:rename_setting_keys",
                                "settings:add_new_settings",
-                               "execute_release_1.5.0_tasks"]
+                               "execute_release_1.6.0_tasks"]
 
   desc "Runs tasks needed to upgrade from 1.4.0 to 1.5.0"
   task "execute_release_1.5.0_tasks": [
     "active_storage:remove_paperclip_compatibility_in_existing_attachments"
   ]
+
+  desc "Runs tasks needed to upgrade from 1.5.0 to 1.6.0"
+  task "execute_release_1.6.0_tasks": [
+    "db:calculate_tsv"
+  ]
 end
diff --git a/lib/tasks/db.rake b/lib/tasks/db.rake
index 7896eacdf..cb6b20f92 100644
--- a/lib/tasks/db.rake
+++ b/lib/tasks/db.rake
@@ -5,4 +5,15 @@ namespace :db do
     I18n.enforce_available_locales = false
     load(Rails.root.join("db", "dev_seeds.rb"))
   end
+
+  desc "Calculates the TSV column for all comments and proposal notifications"
+  task calculate_tsv: :environment do
+    logger = ApplicationLogger.new
+
+    logger.info "Calculating tsvector for comments"
+    Comment.with_hidden.find_each(&:calculate_tsvector)
+
+    logger.info "Calculating tsvector for proposal notifications"
+    ProposalNotification.with_hidden.find_each(&:calculate_tsvector)
+  end
 end
diff --git a/spec/components/admin/search_component_spec.rb b/spec/components/admin/search_component_spec.rb
new file mode 100644
index 000000000..196735d52
--- /dev/null
+++ b/spec/components/admin/search_component_spec.rb
@@ -0,0 +1,31 @@
+require "rails_helper"
+
+describe Admin::SearchComponent do
+  describe "#hidden_current_filter_tag" do
+    context "controller responds to current_filter", controller: ApplicationController do
+      it "is present when the controller has a current filter" do
+        allow(controller).to receive(:current_filter).and_return("all")
+
+        render_inline Admin::SearchComponent.new(label: "Search")
+
+        expect(page).to have_field "filter", type: :hidden, with: "all"
+      end
+
+      it "is not present when the controller has no current filter" do
+        render_inline Admin::SearchComponent.new(label: "Search")
+
+        expect(page).not_to have_field "filter", type: :hidden
+        expect(page).not_to have_field "filter"
+      end
+    end
+
+    context "controller does not respond to current_filter", controller: ActionController::Base do
+      it "is not present" do
+        render_inline Admin::SearchComponent.new(label: "Search")
+
+        expect(page).not_to have_field "filter", type: :hidden
+        expect(page).not_to have_field "filter"
+      end
+    end
+  end
+end
diff --git a/spec/lib/tasks/db_spec.rb b/spec/lib/tasks/db_spec.rb
new file mode 100644
index 000000000..118d9d00c
--- /dev/null
+++ b/spec/lib/tasks/db_spec.rb
@@ -0,0 +1,39 @@
+require "rails_helper"
+
+describe "rake db:calculate_tsv" do
+  before { Rake::Task["db:calculate_tsv"].reenable }
+
+  let :run_rake_task do
+    Rake.application.invoke_task("db:calculate_tsv")
+  end
+
+  it "calculates the tsvector for comments, including hidden ones" do
+    comment = create(:comment)
+    hidden = create(:comment, :hidden)
+    comment.update_column(:tsv, nil)
+    hidden.update_column(:tsv, nil)
+
+    expect(comment.reload.tsv).to be nil
+    expect(hidden.reload.tsv).to be nil
+
+    run_rake_task
+
+    expect(comment.reload.tsv).not_to be nil
+    expect(hidden.reload.tsv).not_to be nil
+  end
+
+  it "calculates the tsvector for proposal notifications, including hidden ones" do
+    notification = create(:proposal_notification)
+    hidden = create(:proposal_notification, :hidden)
+    notification.update_column(:tsv, nil)
+    hidden.update_column(:tsv, nil)
+
+    expect(notification.reload.tsv).to be nil
+    expect(hidden.reload.tsv).to be nil
+
+    run_rake_task
+
+    expect(notification.reload.tsv).not_to be nil
+    expect(hidden.reload.tsv).not_to be nil
+  end
+end
diff --git a/spec/models/comment_spec.rb b/spec/models/comment_spec.rb
index 7123c9605..f98c86172 100644
--- a/spec/models/comment_spec.rb
+++ b/spec/models/comment_spec.rb
@@ -193,4 +193,25 @@ describe Comment do
       expect(Comment.public_for_api).to be_empty
     end
   end
+
+  describe ".search" do
+    it "searches by body" do
+      comment = create(:comment, body: "I agree")
+
+      expect(Comment.search("agree")).to eq([comment])
+    end
+
+    it "searches by commentable title" do
+      proposal = create(:proposal, title: "More wood!")
+      comment = create(:comment, body: "I agree", commentable: proposal)
+
+      expect(Comment.search("wood")).to eq([comment])
+    end
+
+    it "does not return non-matching records" do
+      create(:comment, body: "I agree")
+
+      expect(Comment.search("disagree")).to be_empty
+    end
+  end
 end
diff --git a/spec/models/proposal_notification_spec.rb b/spec/models/proposal_notification_spec.rb
index 4bd337c36..682ec9ed4 100644
--- a/spec/models/proposal_notification_spec.rb
+++ b/spec/models/proposal_notification_spec.rb
@@ -42,6 +42,26 @@ describe ProposalNotification do
     end
   end
 
+  describe ".search" do
+    it "searches by title" do
+      notification = create(:proposal_notification, title: "Check this!", body: "It's awesome!")
+
+      expect(ProposalNotification.search("Check")).to eq([notification])
+    end
+
+    it "searches by body" do
+      notification = create(:proposal_notification, title: "Check this!", body: "It's awesome!")
+
+      expect(ProposalNotification.search("awesome")).to eq([notification])
+    end
+
+    it "does not return non-matching records" do
+      create(:proposal_notification, title: "Check this!", body: "It's awesome!")
+
+      expect(ProposalNotification.search("terrible")).to be_empty
+    end
+  end
+
   describe "minimum interval between notifications" do
     before do
       Setting[:proposal_notification_minimum_interval_in_days] = 3
diff --git a/spec/models/search_cache_spec.rb b/spec/models/search_cache_spec.rb
new file mode 100644
index 000000000..03dc09368
--- /dev/null
+++ b/spec/models/search_cache_spec.rb
@@ -0,0 +1,27 @@
+require "rails_helper"
+
+describe SearchCache do
+  describe "#calculate_tsvector" do
+    it "calculates the tsv column of a record" do
+      debate = create(:debate)
+      debate.update_column(:tsv, nil)
+
+      expect(debate.reload.tsv).to be_nil
+
+      debate.calculate_tsvector
+
+      expect(debate.reload.tsv).not_to be_nil
+    end
+
+    it "calculates the tsv column of a hidden record" do
+      debate = create(:debate, :hidden)
+      debate.update_column(:tsv, nil)
+
+      expect(debate.reload.tsv).to be_nil
+
+      debate.calculate_tsvector
+
+      expect(debate.reload.tsv).not_to be_nil
+    end
+  end
+end
diff --git a/spec/system/admin/hidden_budget_investments_spec.rb b/spec/system/admin/hidden_budget_investments_spec.rb
index 29c8a0a72..9f3f20bfe 100644
--- a/spec/system/admin/hidden_budget_investments_spec.rb
+++ b/spec/system/admin/hidden_budget_investments_spec.rb
@@ -31,9 +31,6 @@ describe "Admin hidden budget investments", :admin do
     investment = create(:budget_investment, :hidden, heading: heading)
     visit admin_hidden_budget_investments_path
 
-    click_link "Pending"
-
-    expect(page).not_to have_link "Pending"
     expect(page).to have_content(investment.title)
 
     click_button "Confirm moderation"
@@ -46,18 +43,18 @@ describe "Admin hidden budget investments", :admin do
 
   scenario "Current filter is properly highlighted" do
     visit admin_hidden_budget_investments_path
-    expect(page).not_to have_link("All")
-    expect(page).to have_link("Pending")
-    expect(page).to have_link("Confirmed")
-
-    visit admin_hidden_budget_investments_path(filter: "without_confirmed_hide")
+    expect(page).not_to have_link("Pending")
     expect(page).to have_link("All")
     expect(page).to have_link("Confirmed")
-    expect(page).not_to have_link("Pending")
+
+    visit admin_hidden_budget_investments_path(filter: "all")
+    expect(page).to have_link("Pending")
+    expect(page).not_to have_link("All")
+    expect(page).to have_link("Confirmed")
 
     visit admin_hidden_budget_investments_path(filter: "with_confirmed_hide")
-    expect(page).to have_link("All")
     expect(page).to have_link("Pending")
+    expect(page).to have_link("All")
     expect(page).not_to have_link("Confirmed")
   end
 
diff --git a/spec/system/admin/hidden_content_search_spec.rb b/spec/system/admin/hidden_content_search_spec.rb
new file mode 100644
index 000000000..183f72ac8
--- /dev/null
+++ b/spec/system/admin/hidden_content_search_spec.rb
@@ -0,0 +1,125 @@
+require "rails_helper"
+
+describe "Hidden content search", :admin do
+  scenario "finds matching records" do
+    create(:budget_investment, :hidden, title: "New football field")
+    create(:budget_investment, :hidden, title: "New basketball field")
+    create(:budget_investment, :hidden, title: "New sports center")
+
+    visit admin_hidden_budget_investments_path
+    fill_in "search", with: "field"
+    click_button "Search"
+
+    expect(page).not_to have_content "New sports center"
+    expect(page).to have_content "New football field"
+    expect(page).to have_content "New basketball field"
+  end
+
+  scenario "returns no results if no records match the term" do
+    create(:comment, :hidden, body: "I like this feature")
+
+    visit admin_hidden_comments_path
+    fill_in "search", with: "love"
+    click_button "Search"
+
+    expect(page).to have_content "There are no hidden comments"
+    expect(page).not_to have_content "I like this feature"
+    expect(page).not_to have_content "I hate this feature"
+  end
+
+  scenario "returns all records when the search term is empty" do
+    create(:debate, :hidden, title: "Can we make it better?")
+    create(:debate, :hidden, title: "Can we make it worse?")
+
+    visit admin_hidden_debates_path(search: "worse")
+
+    expect(page).not_to have_content "Can we make it better?"
+    expect(page).to have_content "Can we make it worse?"
+
+    fill_in "search", with: " "
+    click_button "Search"
+
+    expect(page).to have_content "Can we make it better?"
+    expect(page).to have_content "Can we make it worse?"
+    expect(page).not_to have_content "There are no hidden debates"
+  end
+
+  scenario "keeps search parameters after restoring a record" do
+    create(:proposal_notification, :hidden, title: "Someone is telling you something")
+    create(:proposal_notification, :hidden, title: "Someone else says whatever")
+    create(:proposal_notification, :hidden, title: "Nobody is saying anything")
+
+    visit admin_hidden_proposal_notifications_path(search: "Someone")
+
+    expect(page).to have_content "Someone is telling you something"
+    expect(page).to have_content "Someone else says whatever"
+    expect(page).not_to have_content "Nobody is saying anything"
+
+    within "tr", text: "Someone is telling you something" do
+      accept_confirm("Are you sure? Restore") { click_button "Restore" }
+    end
+
+    expect(page).not_to have_content "Someone is telling you something"
+    expect(page).to have_content "Someone else says whatever"
+    expect(page).not_to have_content "Nobody is saying anything"
+  end
+
+  scenario "keeps search parameters after confirming moderation" do
+    create(:proposal, :hidden, title: "Reduce the incoming traffic")
+    create(:proposal, :hidden, title: "Reduce pollution")
+    create(:proposal, :hidden, title: "Increment pollution")
+
+    visit admin_hidden_proposals_path(search: "Reduce")
+
+    expect(page).to have_content "Reduce the incoming traffic"
+    expect(page).to have_content "Reduce pollution"
+    expect(page).not_to have_content "Increment pollution"
+
+    within("tr", text: "Reduce the incoming traffic") { click_button "Confirm moderation" }
+
+    expect(page).not_to have_content "Reduce the incoming traffic"
+    expect(page).to have_content "Reduce pollution"
+    expect(page).not_to have_content "Increment pollution"
+  end
+
+  scenario "keeps search parameters while browsing through filters" do
+    create(:user, :hidden, username: "person1")
+    create(:user, :hidden, username: "alien1")
+    create(:user, :hidden, :with_confirmed_hide, username: "person2")
+    create(:user, :hidden, :with_confirmed_hide, username: "alien2")
+
+    visit admin_hidden_users_path(search: "person")
+
+    expect(page).to have_content "person1"
+    expect(page).not_to have_content "person2"
+    expect(page).not_to have_content "alien1"
+    expect(page).not_to have_content "alien2"
+
+    click_link "Confirmed"
+
+    expect(page).not_to have_content "person1"
+    expect(page).to have_content "person2"
+    expect(page).not_to have_content "alien1"
+    expect(page).not_to have_content "alien2"
+  end
+
+  scenario "keeps filter parameters after searching" do
+    create(:user, :hidden, :with_confirmed_hide, username: "person1")
+    create(:user, :hidden, :with_confirmed_hide, username: "alien1")
+    create(:user, :hidden, username: "person2")
+    create(:user, :hidden, username: "alien2")
+
+    visit admin_hidden_users_path(filter: "with_confirmed_hide")
+
+    fill_in "search", with: "alien"
+    click_button "Search"
+
+    expect(page).not_to have_content "person1"
+    expect(page).to have_content "alien1"
+    expect(page).not_to have_content "person2"
+    expect(page).not_to have_content "alien2"
+
+    expect(page).to have_content "Confirmed"
+    expect(page).not_to have_link "Confirmed"
+  end
+end