In Clutter Control, Jeff Campbell has pointed out some of the psychological landmarks indicating clutter may be interfering with a happy and productive life:

• It is creating feelings of depression, anxiety or desperation.
• The need for more or newer stuff seems insatiable.
• You feel like you are not the master of your own life anymore: It feels like you are being controlled by your possessions.
• The disorder of your living space prevents you from feeling comfortable or creative or happy when you are there.
• You deride yourself for not being more organized.
• You’re in chronic conflict with other household members over this issue.
• You’re ashamed to have friends or relatives over to the house because it’s such a mess and you’re feeling more and more isolated or eccentric as a result.