Labrador Retrievers are amiable, trainable, intelligent, & gentle. They make terrific outdoor companions.
Their calm, steady nature & drive to please make them dependable. Yorkshire Terriers are little but big-hearted. They'll cuddle on your lap & love your attention.
They'll also love & understand you. They're small enough to travel with. Many airlines allow them in the cabin (although, sadly, the number is falling).
Dogs must understand facial emotions to provide emotional assistance. Corgis are king because they're vigilant, aware of their surroundings, & may help with many mental problems.
Their intelligence and trainability allow them to follow orders. Cavalier King Charles Spaniels are called "love sponges" because they are very affectionate.
Originally bred for comfort & companionship, they're wonderful for anyone who needs a large snuggle, especially those with Post-Traumatic Stress Disorder & depression.
Larger dogs make people feel safer. A Golden Retriever can detect your feelings & comfort you by lying next to you. Loyal, friendly, & lively, they can relieve depression. They're well-behaved & follow commands well.