FORthelasthalfcenturypsychologyhasbeenconsumedwithasingletopiconly-mentalillness-andhasdonefairlywellwithit.Psychologistscannowmeasuresuchonce-fuzzyconceptsasdepression,schizophrenia,andalcoholismwithconsiderableprecision.Wenowknowagooddealabouthowthesetroublesdevelopacrossthelifespa