抑うつが役に立つのはどのような状況においてか
ガットは歴史上の人物に関する鮮やかなケース・スタディーを用いて、抑うつによる社会的引きこもりと集中的な思考は、人生の大問題が引き起こす大規模な変化に対処する力を高める場合があると指摘したうえで、非生産的な抑うつに陥ったままになってしまう人もいると論じた。
人生に関わるような大きな失敗は、新たな戦略を見つけるために大きな労力を割く動機になる場合がある。だが、ガットやネトル、ホークセマらが指摘しているとおり、そのような状況における反芻と社会的引きこもりが、常に最適な反応であるとは言い難い。
本稿ではここまで、落ち込んだ気分とうつ病の機能に関してこれまでに提唱された中でももっとも説得力のある説をいくつか紹介した。こうした説のうちどれが正しいのかが議論され続けているが、これは不要な議論であり、実際にはすべての説が当てはまり得る。そして何より、抑うつが果たし得る機能は何か、という問いから、抑うつが役に立つのはどのような状況においてか、という問いに焦点を移すことで、各機能の重要性や関係性をより明らかにできるようになる。
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